[4] Recent changes to this document  Updated! 
(Part of C++ FAQ, Copyright © 1991-2011, Marshall Cline, cline@parashift.com)

FAQs in section [4]:

• [4.1] What updates were made for the 07/11 release?  New! 
• [4.2] What updates were made for the 05/11 release?  New! 
• [4.3] What updates were made for the 03/11 release?
• [4.4] What updates were made for the 08/10 release?
• [4.5] What updates were made for the 06/10 release?
• [4.6] What updates were made for the 05/10 release?
• [4.7] What updates were made for the 04/10 release?
• [4.8] What updates were made for the 03/10 release?
• [4.9] What updates were made for the 01/10 release?
• [4.10] What updates were made for the 09/09 release?
• [4.11] What updates were made for the 06/09 release?
• [4.12] What updates were made for the 01/09 release?
• [4.13] What updates were made for the 09/06 release?
• [4.14] What updates were made for the 03/06 release?
• [4.15] What updates were made for the 10/05 release?
• [4.16] What updates were made for the 07/05 release?
• [4.17] What updates were made for the 06/05 release?
• [4.18] What updates were made for the 05/05 release?
• [4.19] What updates were made for the 04/05 release?
• [4.20] What updates were made for the 03/05 release?
• [4.21] What updates were made for the 02/05 release?
• [4.22] What updates were made for the 12/04 release?
• [4.23] What updates were made for the 06/04 release?
• [4.24] What updates were made for the 08/03 release?
• [4.25] What updates were made for the 06/03 release?
• [4.26] What updates were made for the 05/03 release?
• [4.27] What updates were made for the 04/03 release?
• [4.28] What updates were made for the 03/03 release?
• [4.29] What updates were made for the 02/03 release?
• [4.30] What updates were made for the 01/03 release?
• [4.31] What updates were made for the 12/02 release?
• [4.32] What updates were made for the 09/02 release?
• [4.33] What updates were made for the 06/02 release?
• [4.34] What updates were made for the 05/02 release?
• [4.35] What updates were made for the 04/02 release?
• [4.36] What updates were made for the 03/02 release?
• [4.37] What updates were made for the 08/01 release?
• [4.38] What updates were made for the 04/01 release?
• [4.39] What updates were made for the 07/00 release?
• [4.40] What updates were made for the 03/00 release?
• [4.41] What updates were made for the 01/00 release?
• [4.42] What updates were made for the 10/99 release?
• [4.43] What updates were made for the 07/99 release?
• [4.44] What updates were made for the 06/98 release?
• [4.45] What updates were made for the 05/98 release?
• [4.46] What updates were made for the 09/97 release?
• [4.47] What updates were made for the 01/97 release?
• [4.48] What updates were made for the 11/96 release?
• [4.49] What updates were made for the 10/96 release?
• [4.50] What updates were made for the 09/96 release?
• [4.51] What updates were made for the 08/96 release?
• [4.52] What updates were made for the 07/96 release?
• [4.53] What updates were made for the 06/96 release?
• [4.54] What updates were made for the 05/96 release?
• [4.55] What updates were made for the 04/96 release?
• [4.56] What updates were made for the 03/96 release?
• [4.57] What updates were made for the 09/95 release?
• [4.58] What updates were made for the 06/95 release?
• [4.59] What updates were made for the 04/95 release?
• [4.60] What updates were made for the 03/95 release?
• [4.61] What updates were made for the 01/95 release?
• [4.62] What updates were made for the 12/94 release?
• [4.63] What updates were made for the 11/94 release?
• [4.64] What updates were made for the 08/94 release?
• [4.65] What updates were made before 08/94?

2 New FAQs:

• [2.14] Where can I find the C++ FAQ translated into Spanish?
  (with much thanks to translator Osmar Lizarraga)
• [4.1] What updates were made for the 07/11 release?

17 Changed FAQs:

• [2.15] Where can I find the C++ FAQ translated into Turkish?
  (with much thanks to new translator Murat Ahmet Genc)
• [13.9] What are some guidelines / "rules of thumb" for overloading operators?
  (fixed some typos thanks to alert reader Thiago Cesar Vieira)
• [13.12] I still don't get it. Why shouldn't my Matrix class's interface look like an array-of-array?
  (fixed a typo thanks to alert reader Thiago Cesar Vieira)
• [29.11] Is it okay if a lot of numbers appear in my code?
  (fixed a typo thanks to Thomas Middeldorp)
• [32.1] What do I need to know when mixing C and C++ code?
  (fixed a typo thanks to Thomas Middeldorp)
• [33.8] How do I declare a pointer-to-member-function that points to a const member function?
  (fixed a typo in the typedef thanks to alert reader Stephen Bennett)
• [33.13] What the heck is a functionoid, and why would I use one?
  (fixed a typo thanks to Thomas Middeldorp)
• [34.3] Is the storage for a std::vector<T> guaranteed to be contiguous?
  (fixed a typo thanks to Thomas Middeldorp)
• [35.2] What's the syntax / semantics for a "class template"?
  (fixed a typo thanks to Thomas Middeldorp)
• [35.13] How can I avoid linker errors with my template functions?
  (fixed a typo thanks to Thomas Middeldorp)
• [35.15] How can I avoid linker errors with my template classes?
  (fixed a typo thanks to Thomas Middeldorp)
• [35.21] How can I create a container-template that allows my users to supply the type of the underlying container that actually stores the values?
  (fixed a typo thanks to Thomas Middeldorp)
• [36.10] How do I serialize objects that contain pointers to other objects, but those pointers form a tree with no cycles and only "trivial" joins?
  (fixed a typo thanks to Thomas Middeldorp)
• [36.11] How do I serialize objects that contain pointers to other objects, and those pointers form a graph that might have cycles or non-trivial joins?
  (fixed a typo thanks to Thomas Middeldorp)
• [37.4] Where can I get help on how to use STL?
  (fixed some dead links thanks to Thomas Middeldorp)
• [37.5] How can you tell if you have a dynamically typed C++ class library?
  (fixed a typo thanks to Thomas Middeldorp)
• [38.13] Is it possible to convert C++ to C?
  (fixed a typo thanks to Thomas Middeldorp)

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1 New FAQs:

• [4.2] What updates were made for the 05/11 release?

3 Changed FAQs:

• [10.13] Can I add = initializer; to the declaration of a class-scope static const data member?
  (added const to definition of Fred::maximum thanks to Marcel Schriber)
• [16.17] But the previous FAQ's code is SOOOO tricky and error prone! Isn't there a simpler way?
  (minor wordsmithing/grammatical improvement)
• [17.5] Okay, so you're saying exception handling is easy and simple, right?
  (minor wordsmithing/grammatical improvement)

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6 New FAQs:

• [2.3] Where can I find the C++ FAQ translated into Belorussian (Minsk)?
  (with much thanks to translator M. Ruzkowski)
• [2.8] Where can I find the C++ FAQ translated into German?
  (with much thanks to translator Julian Albrecht)
• [4.3] What updates were made for the 03/11 release?
• [8.7] What does it mean that a reference must refer to an object, not a dereferenced NULL pointer?
  (thanks to a suggestion from Brendan Iribe)
• [10.22] What is the purpose of the explicit keyword?
  (thanks to Joseph Coffland)
• [15.22] How can I print a char as a number? How can I print a char* so the output shows the pointer's numeric value?
  (thanks to some great work by Paul Feraud)

24 Changed FAQs:

• [2.16] Where can I find the C++ FAQ translated into Romanian?
  (fixed a typo thanks to alert reader Riff)
• [10.7] Should you use the this pointer in the constructor?
  (fixed a typo thanks to Thomas Middeldorp)
• [10.21] Why am I getting an error after declaring a Foo object via Foo x(Bar())?
  (added some more fine print on the second solution thanks to alert reader Dan Nabutovsky)
• [11.14] Is there a way to force new to allocate memory from a specific memory area?
  (typo in the code (null vs. NULL) was fixed thanks to Eli Bendersky)
• [12.4] I'm creating a derived class; should my assignment operator call my base class's assignment operator?
  (fixed a typo thanks to Thomas Middeldorp)
• [13.12] I still don't get it. Why shouldn't my Matrix class's interface look like an array-of-array?
  (fixed two typos thanks to Thomas Middeldorp)
• [16.2] Is it safe to delete the same pointer twice?
  (fixed a typo thanks to Thomas Middeldorp)
• [16.12] What if I forget the [] when deleteing an array allocated via new T[n]?
  (fixed a typo thanks to Thomas Middeldorp)
• [16.13] Can I drop the [] when deleteing an array of some built-in type (char, int, etc)?
  (fixed a typo thanks to Thomas Middeldorp)
• [16.15] Is it legal (and moral) for a member function to say delete this?
  (fixed some typos thanks to Thomas Middeldorp)
• [16.25] Can you absolutely prevent people from subverting the reference counting mechanism, and if so, should you?
  (fixed two typos thanks to Thomas Middeldorp)
• [16.26] Can I use a garbage collector in C++?
  (fixed a typo thanks to Thomas Middeldorp)
• [17.2] I'm still not convinced: a 4-line code snippet shows that return-codes aren't any worse than exceptions; why should I therefore use exceptions on an application that is orders of magnitude larger?
  (improved the wording thanks to Thomas Middeldorp)
• [17.8] How can I handle a constructor that fails?
  (added a discussion about memory leaks thanks to an insightful question from Wojciech "Spook" Sura)
• [18.1] What is "const correctness"?
  (fixed two typos thanks to Thomas Middeldorp)
• [18.17] Why am I getting an error converting a Foo** → Foo const**?
  (fix two typos thanks to Thomas Middeldorp)
• [20.5] How can a member function in my derived class call the same function from its base class?
  (fixed a typo thanks to Thomas Middeldorp)
• [20.7] When should my destructor be virtual?
  (changed "explicit destructor" to "explicitly defined destructor" to avoid confusion with the explicit keyword used with constructors)
• [21.2] Converting Derived* → Base* works OK; why doesn't Derived** → Base** work?
  (fixed a typo thanks to Thomas Middeldorp)
• [23.9] What's the meaning of, Warning: Derived::f(char) hides Base::f(double)?
  (fixed a typo thanks to Thomas Middeldorp)
• [25.6] Is there a simple way to visualize all these tradeoffs?
  (improved the wording and fixed some typos thanks to Rob Swarbrick and Thomas Middeldorp and Martinho Fernandes)
• [25.7] Can you give another example to illustrate the above disciplines?
  (fixed a typo thanks to Thomas Middeldorp)
• [27.1] What are some good C++ coding standards?
  (fixed a typo thanks to Thomas Middeldorp)
• [29.2] Where do I start? Why do I feel so confused, so stupid?
  (fixed two broken links thanks to alert reader Dan Nabutovsky)

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Generic changes:

• Reverted the document's name back to its original name: C++ FAQ. Reason: the "Lite" suffix was an anachronism. The document has grown to 531 FAQs in 40 chapters/sections with well over 13,000 internal cross-references. It is far from "lite."
• Started some much-needed revamping of the templates section. That still needs a lot of work, and I welcome any additions. There are lots of topics that should be added!!
• As always, I am soliciting your additions for any section, templates or otherwise. Please send them in!

13 New FAQs:

• [2.5] Where can I find the C++ FAQ translated into Bulgarian?
  (with much thanks to translator Anthony Ivanov)
• [2.16] Where can I find the C++ FAQ translated into Romanian?
  (with much thanks to translator Emil Cataranciuc)
• [4.4] What updates were made for the 08/10 release?
• [6.19] How can you help make the C++ FAQ even better??!??
  (to coalesce all the "please help" messages that have traditionally been scattered throughout the FAQ)
• [10.10] What about returning a local variable by value? Does the local exist as a separate object, or does it get optimized away?
  (split this from [10.9] and rewrote to clarify the message)
• [10.13] Can I add = initializer; to the declaration of a class-scope static const data member?
  (thanks to a suggestion from Chris Parker)
• [17.2] I'm still not convinced: a 4-line code snippet shows that return-codes aren't any worse than exceptions; why should I therefore use exceptions on an application that is orders of magnitude larger?
• [17.3] How do exceptions simplify my function return type and parameter types?
• [17.4] What does it mean that exceptions separate the "good path" (or "happy path") from the "bad path"?
• [17.5] Okay, so you're saying exception handling is easy and simple, right?
• [35.21] How can I create a container-template that allows my users to supply the type of the underlying container that actually stores the values?
  (thanks to Victor Bazarov)
• [35.22] Follow-up to previous: can I pass in the underlying structure and the element-type separately?
  (thanks to Victor Bazarov)
• [35.23] Related: all those proxies must negatively reflect on the speed of my program. Don't they?
  (thanks to Victor Bazarov)

28 Changed FAQs:

• [1.3] Copying Permissions
  (wordsmithing)
• [2.1] Where's the closest mirror site to access this document?
  (updated the URL for the all-in-one compiled-help-file version thanks to Omar Lawand Dalatieh)
• [3.2] Is there a big difference between this on-line C++ FAQ and the C++ FAQ Book?
  (rewrote and updated)
• [5.3] What should I do if I see someone else posting a homework problem?
  (fixed typo thanks to Sergio Perez Camacho)
• [5.13] What about spam?
  (updated the URL thanks to Daniel Krügler)
• [10.9] Does return-by-value mean extra copies and extra overhead?
  (rewrote to clarify the message thanks to Nikola Smiljanic, and split the return-local-variable-by-value information into a separate FAQ)
• [10.11] Why can't I initialize my static member data in my constructor's initialization list?
  (added material showing why some static data member definitions don't have a "= initializer" part)
• [10.12] Why are classes with static data members getting linker errors?
  (added material regarding static const data members with initializer)
• [17.6] Exception handling seems to make my life more difficult; clearly I'm not the problem, am I??
  (reorganized the section, moving this FAQ up toward the beginning)
• [17.7] I have too many try blocks; what can I do about it?
  (reorganized the section, moving this FAQ up toward the beginning)
• [18.17] Why am I getting an error converting a Foo** → Foo const**?
  (added a cross-reference to the FAQ about converting Derived** to Base** thanks to a suggestion from Miloslavskiy Alexander)
• [20.7] When should my destructor be virtual?
  (clarified the wording of the virtual-destructor rule thanks to Nikola Smiljanic)
• [21.2] Converting Derived* → Base* works OK; why doesn't Derived** → Base** work?
  (added a cross-reference to the FAQ about converting Foo** to Foo const** thanks to a suggestion from Miloslavskiy Alexander)
• [23.4] When should someone use private virtuals?
  (coalesced duplicate definition of myOp() thanks to alert readers Nikola Smiljanic and Antoine W. Campagna)
• [25.6] Is there a simple way to visualize all these tradeoffs?
  (fixed a typo in the text thanks to Nikola Smiljanic)
• [25.9] Where in a hierarchy should I use virtual inheritance?
  (fixed a typo thanks to Miloslavskiy Alexander)
• [31.7] Sounds like I should never use reference semantics, right?
  (fixed a typo thanks to Miloslavskiy Alexander)
• [32.8] How can I pass an object of a C++ class to/from a C function?
  (rewrote prose to clarify issues surrounding different binary representations for Base* and Derived*)
• [33.8] How do I declare a pointer-to-member-function that points to a const member function?
  (fixed a typo in the code thanks to alert readers James Lingard, Stephen Howe and Andrew Denner)
• [33.10] Can I convert a pointer-to-member-function to a void*?
  (added technical details and rationale for why this sort of comparison is illegal thanks to a suggestion from Miloslavskiy Alexander)
• [33.11] Can I convert a pointer-to-function to a void*?
  (added technical details and rationale for why this sort of comparison is illegal thanks to a suggestion from Miloslavskiy Alexander)
• [34.5] How can I insert/access/change elements from a linked list/hashtable/etc?
  (fixed a typo in the text thanks to Nikola Smiljanic)
• [34.6] Can I have a container of smart pointers to my objects?
  (fixed a bug in the code thanks to Nikola Smiljanic and Miloslavskiy Alexander)
• [35.2] What's the syntax / semantics for a "class template"?
  (moved one of the method template definitions outside the class template body to show how that's done thanks to a suggestion from John Dickson)
• [35.14] How does the C++ keyword export help with template linker errors?
  (rewrote because the C++0x committee has voted export out of the standard, thanks to alert reader Alex Dumov)
• [36.2] How do I select the best serialization technique?
  (fixed a typo in the text thanks to Nikola Smiljanic)
• [36.4] How do I serialize/unserialize simple types like numbers, characters, strings, etc.?
  (fixed a typo in the FAQ title thanks to Nikola Smiljanic)
• [36.8] How do I serialize objects that are part of an inheritance hierarchy and that don't contain pointers to other objects?
  (added technical details and rationale for why unique[className] = unique.size() could cause an error thanks to a suggestion from Miloslavskiy Alexander)

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3 New FAQs:

• [4.5] What updates were made for the 06/10 release?
• [33.8] How do I declare a pointer-to-member-function that points to a const member function?
  (thanks to David Norris)
• [33.9] What is the difference between the .* and ->* operators?
  (thanks to David Norris)

11 Changed FAQs:

• [6.16] Will I sometimes use any so-called "evil" constructs?
  (strengthened the wording)
• [13.9] What are some guidelines / "rules of thumb" for overloading operators?
  (fixed a typo ("should have should have") thanks to Miloslavskiy Alexander)
• [18.6] What does "Fred const& x" mean?
  (fixed a typo in a variable name (x instead of p) thanks to David Norris)
• [27.1] What are some good C++ coding standards?
  (rewrote to better explain the emotional reactions against coding standards and to strengthen the case for them)
• [28.5] What are some best-of-breed C++ morality guides?
  (updated info on Effective C++ book because of its Third Edition thanks to Terry Poulin)
• [29.17] Why doesn't my floating-point comparison work?
  (added a reference to a review critical to "Numerical Recipes" thanks to K. Frank, plus added NETLIB to the list of alternative sources for numerical algorithms)
• [30.1] What's the difference between C++ and Smalltalk?
  (rewrote the last paragraph, softening the language with respect to how many C++ programmers come from a Smalltalk background and strengthening the language about avoiding language bigotry)
• [33.5] How can I avoid syntax errors when creating pointers to members?
  (split from the FAQ about using a macro to call through a pointer-to-member-function)
• [33.6] How can I avoid syntax errors when calling a member function using a pointer-to-member-function?
  (split from the FAQ about using a macro to call through a pointer-to-member-function)
• [37.7] Where can I ftp the code that accompanies "Numerical Recipes"?
  (added a reference to a review critical of "Numerical Recipes" thanks to K. Frank, plus added a list of alternative sources for numerical algorithms)
• [39.4] What should be done with macros that contain if?
  (fixed a typo ("the" vs. "they") thanks to David Norris)

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1 New FAQs:

• [4.6] What updates were made for the 05/10 release?

8 Changed FAQs:

• [10.21] Why am I getting an error after declaring a Foo object via Foo x(Bar())?
  (added a new solution thanks to Paul A. Rombouts)
• [16.6] Do I need to check for NULL after p = new Fred()?
  (strengthened the descriptions to clarify that compilers which don't throw on allocation failure are ancient, not just old)
• [16.10] In p = new Fred(), does the Fred memory "leak" if the Fred constructor throws an exception?
  (fixed the "equivalent" code to show that the pointer isn't changed until the ctor succeeds thanks to Michael Cox)
• [18.6] What does "Fred const& x" mean?
  (fixed a copy-error ("pointer" vs. "reference") thanks to Adam Scott, Cameron McCormack, Stefan Pantschitz)
• [18.8] What does "const X& x" mean?
  (fixed a copy-error ("X const&" vs. "const X&") thanks to Adam Scott, Clemens Lode, Cameron McCormack, Mike Leibensperger)
• [18.9] What does "const X* x" mean?
  (fixed a copy-error ("X const*" vs. "const X*") thanks to Adam Scott)
• [18.17] Why am I getting an error converting a Foo** → Foo const**?
  (strengthened and clarified via a new discussion at the end thanks to Miloslavskiy Alexander)
• [26.13] What should be returned from a function?
  (fixed a typo in a code snippet ("const X const*") and two typos in the prose, all thanks to John Dickson)

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2 New FAQs:

• [4.7] What updates were made for the 04/10 release?
• [7.7] Can a method directly access the non-public members of another instance of its class?
  (thanks to a suggestion from Darren Sargent and Vikas Rangarajan)

63 Changed FAQs:

• [2.11] Where can I find the C++ FAQ translated into Polish?
  (updated the Polish translation's URL)
• [4.23] What updates were made for the 06/04 release?
  (updated the Polish translation's URL)
• [4.32] What updates were made for the 09/02 release?
  (updated the Polish translation's URL)
• [8.5] How can you reseat a reference to make it refer to a different object?
  (changed const X* to X const*)
• [10.20] What is the "Named Parameter Idiom"?
  (changed const X& to X const&)
• [10.21] Why am I getting an error after declaring a Foo object via Foo x(Bar())?
  (changed const X& to X const&)
• [12.2] Why should I worry about "self assignment"?
  (changed const X& to X const&)
• [12.3] OK, OK, already; I'll handle self-assignment. How do I do it?
  (clarified the "don't go out of your way to make self-assignment fast" paragraphs at the end thanks to a question from Stan; and changed const X& to X const&)
• [12.4] I'm creating a derived class; should my assignment operator call my base class's assignment operator?
  (changed const X& to X const&)
• [13.1] What's the deal with operator overloading?
  (changed const X& to X const&)
• [13.10] How do I create a subscript operator for a Matrix class?
  (changed const X& to X const&)
• [13.12] I still don't get it. Why shouldn't my Matrix class's interface look like an array-of-array?
  (changed const X& to X const&)
• [15.8] How can I provide printing for my class Fred?
  (changed const X& to X const&)
• [15.9] But shouldn't I always use a printOn() method rather than a friend function?
  (changed const X& to X const&)
• [15.10] How can I provide input for my class Fred?
  (changed const X& to X const&)
• [15.11] How can I provide printing for an entire hierarchy of classes?
  (changed const X& to X const&)
• [15.12] How can I open a stream in binary mode?
  (changed const X& to X const&)
• [16.17] But the previous FAQ's code is SOOOO tricky and error prone! Isn't there a simpler way?
  (changed const X& to X const&)
• [16.18] But the above Matrix class is specific to Fred! Isn't there a way to make it generic?
  (changed const X& to X const&)
• [16.19] What's another way to build a Matrix template?
  (changed const X& to X const&)
• [16.21] How can I force objects of my class to always be created via new rather than as locals or global/static objects?
  (changed const X& to X const&)
• [16.22] How do I do simple reference counting?
  (changed const X& to X const&)
• [16.23] How do I provide reference counting with copy-on-write semantics?
  (changed const X& to X const&)
• [16.24] How do I provide reference counting with copy-on-write semantics for a hierarchy of classes?
  (changed const X& to X const&)
• [17.11] How do I change the string-length of an array of char to prevent memory leaks even if/when someone throws an exception?
  (changed const X& to X const& and const X* to X const*)
• [17.15] What does throw; (without an exception object after the throw keyword) mean? Where would I use it?
  (changed const X& to X const&)
• [18.1] What is "const correctness"?
  (changed const X& to X const& and const X* to X const*)
• [18.4] What does "Fred const* p" mean?
  (changed const X* to X const*)
• [18.5] What's the difference between "Fred const* p", "Fred* const p" and "Fred const* const p"?
  (changed const X* to X const*)
• [18.6] What does "Fred const& x" mean?
  (changed const X& to X const&)
• [18.7] Does "Fred& const x" make any sense?
  (changed const X& to X const&)
• [18.8] What does "const X& x" mean?
  (reversed the sense so X const& is now common and const X& is classic)
• [18.9] What does "const X* x" mean?
  (reversed the sense so X const* is now common and const X* is classic)
• [18.10] What is a "const member function"?
  (changed const X& to X const&)
• [18.11] What's the relationship between a return-by-reference and a const member function?
  (changed const X& to X const&)
• [18.12] What's the deal with "const-overloading"?
  (changed const X& to X const&)
• [18.13] What do I do if I want a const member function to make an "invisible" change to a data member?
  (changed const X* to X const*)
• [18.15] Why does the compiler allow me to change an int after I've pointed at it with a int const*?
  (changed const X* to X const*)
• [18.16] Does "Fred const* p" mean that *p can't change?
  (changed const X* to X const*)
• [18.17] Why am I getting an error converting a Foo** → Foo const**?
  (changed const X* to X const*)
• [21.12] If SortedList has exactly the same public interface as List, is SortedList a kind-of List?
  (changed const X& to X const&)
• [22.5] How do you define a copy constructor or assignment operator for a class that contains a pointer to a (abstract) base class?
  (changed const X& to X const&)
• [23.5] When my base class's constructor calls a virtual function on its this object, why doesn't my derived class's override of that virtual function get invoked?
  (changed const X& to X const&)
• [23.6] Okay, but is there a way to simulate that behavior as if dynamic binding worked on the this object within my base class's constructor?
  (changed const X& to X const&)
• [26.13] What should be returned from a function?
  (changed const X* to X const*)
• [27.10] Are there any lint-like guidelines for C++?
  (changed const X& to X const&)
• [27.14] Should I use "unusual" syntax?
  (changed const X& to X const&)
• [28.4] Should I buy one book, or several?
  (fixed a misspelling thanks to Nigel Colpitts)
• [29.17] Why doesn't my floating-point comparison work?
  (added #include <cmath> to make sure the compiler uses the std::abs(double) overload, rather than std::abs(int))
• [32.5] How can I call a non-system C function f(int,char,float) from my C++ code?
  (changed const X* to X const*)
• [33.13] What the heck is a functionoid, and why would I use one?
  (changed const X& to X const&)
• [33.14] Can you make functionoids faster than normal function calls?
  (changed const X& to X const&)
• [35.2] What's the syntax / semantics for a "class template"?
  (changed const X& to X const&)
• [35.7] My template function does something special when the template type T is int or std::string; how do I write my template so it uses the special code when T is one of those specific types?
  (changed const X& to X const&)
• [35.8] Huh? Can you provide an example of template specialization that doesn't use foo and bar?
  (changed const X& to X const&)
• [35.9] But most of the code in my template function is the same; is there some way to get the benefits of template specialization without duplicating all that source code?
  (changed const X& to X const&)
• [35.16] Why do I get linker errors when I use template friends?
  (changed const X& to X const&)
• [37.3] How can I find a Fred object in an STL container of Fred* such as std::vector<Fred*>?
  (changed const X& to X const& and const X* to X const*)
• [39.1] How do I convert a value (a number, for example) to a std::string?
  (changed const X& to X const&)
• [39.2] How do I convert a std::string to a number?
  (changed const X& to X const&)
• [39.3] Can I templatize the above functions so they work with other types?
  (changed const X& to X const&)
• [39.5] What should be done with macros that have multiple lines?
  (rewrote to reflect current C++ compilers)
• [39.11] How can I create two classes that both know about each other?
  (fixed the return type in the prose from Fred to Fred* thanks to Mark Ruvald)

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2 New FAQs:

• [4.8] What updates were made for the 03/10 release?
• [34.6] Can I have a container of smart pointers to my objects?
  (thanks to Darren Sargent)

6 Changed FAQs:

• [8.5] How can you reseat a reference to make it refer to a different object?
  (reworded the last sentence to avoid confusion (thanks to Cam McKinnon) and to strengthen the conclusion)
• [29.18] Why is cos(x) != cos(y) even though x == y? (Or sine or tangent or log or just about any other floating point computation)
  (fixed a typo ("assemply" vs. "assembly") thanks to Patrick J. LoPresti)
• [29.21] What other "newbie" guides are there for me?
  (added another broken (sorry!) URL for the Correct C++ Tutorial; if anyone has a better link, please let me know)
• [36.9] How do I serialize objects that contain pointers to other objects, but those pointers form a tree with no cycles and no joins?
  (clarified discussion of "trees" and added caveats)
• [36.10] How do I serialize objects that contain pointers to other objects, but those pointers form a tree with no cycles and only "trivial" joins?
  (clarified discussion of "trees" and added, thanks to Ian Goodfellow, added a caveat for pointers that point to a data member of an object rather than to the object itself)
• [38.13] Is it possible to convert C++ to C?
  (updated link to Cfront)

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2 New FAQs:

• [4.9] What updates were made for the 01/10 release?
• [12.4] I'm creating a derived class; should my assignment operator call my base class's assignment operator?
  (inspired by a question from Peter Spiekermann)

4 Changed FAQs:

• [12.3] OK, OK, already; I'll handle self-assignment. How do I do it?
  (rewrote to strengthen the point of not adding an unnecessary "if")
• [34.3] Is the storage for a std::vector<T> guaranteed to be contiguous?
  (added nit about order semantics thanks to Shane Calimlim)
• [35.12] Why can't I separate the definition of my templates class from its declaration and put it inside a .cpp file?
  (fixed a grammatical error (it's vs. its) thanks to Andrew Predoehl)
• [35.14] How does the C++ keyword export help with template linker errors?
  (added Sun Studio thanks to Piero Foscari, and fixed the export code thanks to Sean Hunt)

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1 New FAQs:

• [4.10] What updates were made for the 09/09 release?

5 Changed FAQs:

• [10.8] What is the "Named Constructor Idiom"?
  (changed sin() to std::sin() thanks to Andrey Vihrov)
• [24.6] What are the access rules with private and protected inheritance?
  (wordsmithing thanks to Aron Ahmadia)
• [25.6] Is there a simple way to visualize all these tradeoffs?
  (rewrote to strengthen the prose)
• [29.9] What is the "standard library"? What is included / excluded from it?
  (fixed misspelled word thanks to Andrey Vihrov)
• [29.18] Why is cos(x) != cos(y) even though x == y? (Or sine or tangent or log or just about any other floating point computation)
  (added #include <iostream> thanks to Ives Van Der Flaas)

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1 New FAQs:

• [4.11] What updates were made for the 06/09 release?

3 Changed FAQs:

• [23.4] When should someone use private virtuals?
  (rewrote thanks to Jonathan Roy)
• [29.18] Why is cos(x) != cos(y) even though x == y? (Or sine or tangent or log or just about any other floating point computation)
  (changed sin() to std::sin() thanks to Andrey Vihrov)
• [38.13] Is it possible to convert C++ to C?
  (updated link to LLVM thanks to Stiepan Kovac)

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4 New FAQs:

• [2.10] Where can I find the C++ FAQ translated into Korean?
  (with much thanks to translator Michael Kang)
• [4.12] What updates were made for the 01/09 release?
• [26.13] What should be returned from a function?
  (thanks to Stefan Monov)
• [33.15] What's the difference between a functionoid and a functor?
  (thanks to a question from Dan Kegel and to some pestering by Alf P. Steinbach)

8 Changed FAQs:

• [2.1] Where's the closest mirror site to access this document?
  (added a link to the all-in-one compiled-help-file version thanks to Omar Lawand Dalatieh)
• [10.14] What's the "static initialization order fiasco"?
  (softened the "before main() begins" comment since dynamic initialization of statics might happen after main(); see standard 3.6.2p3; thanks to Alexander Bernauer)
• [15.11] How can I provide printing for an entire hierarchy of classes?
  (added advice on choosing between pure virtual and plain virtual)
• [16.7] How can I convince my (older) compiler to automatically check new to see if it returns NULL?
  (softened the "before main() begins" comment since dynamic initialization of statics might happen after main(); see standard 3.6.2p3; thanks to Alexander Bernauer)
• [23.9] What's the meaning of, Warning: Derived::f(char) hides Base::f(double)?
  (added a delete d to the code so no one gets distracted from the main point by a memory leak thanks to Juha Nieminen)
• [29.3] Should I use void main() or int main()?
  (fixed a typo in one of the subject-index entries that points to this FAQ thanks to Eric Galloway)
• [35.8] Huh? Can you provide an example of template specialization that doesn't use foo and bar?
  (added note about std::numeric_limits<>::max_digits10 thanks to Alessandro Gentilini)
• [40.3] Are there any pretty-printers that reformat C++ source code?
  (added "Uncrustify" thanks to Peter Dufault)

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2 New FAQs:

• [4.13] What updates were made for the 09/06 release?
• [35.18] Why am I getting errors when my template-derived-class uses a nested type it inherits from its template-base-class?
  (thanks to Victor Bazarov)

11 Changed FAQs:

• [2.1] Where's the closest mirror site to access this document?
  (added the new mirror site in China thanks to dd_engi, and changed the output to a table)
• [6.18] What should I tell people who complain that the word "FAQ" is misleading, that it emphasizes the questions rather than the answers, and that we should all start using a different acronym?
  (added "DIRR" acronym thanks to Andrew D. Hwang)
• [13.12] I still don't get it. Why shouldn't my Matrix class's interface look like an array-of-array?
  (wordsmithed)
• [20.6] I have a heterogeneous list of objects, and my code needs to do class-specific things to the objects. Seems like this ought to use dynamic binding but can't figure it out. What should I do?
  (corrected the name of Meyer's "Law of Inversion" thanks to Darren Hiebert)
• [23.3] Should I use protected virtuals instead of public virtuals?
  (fixed a typo in the code (f_double is now f_dbl) thanks to Al-Asham Said)
• [29.18] Why is cos(x) != cos(y) even though x == y? (Or sine or tangent or log or just about any other floating point computation)
  (added #include <iostream> thanks to Phil Buluschek)
• [34.3] Is the storage for a std::vector<T> guaranteed to be contiguous?
  (removed obsolete caveat from when this had not yet been ratified thanks to Alberto Ganesh Barbati and Gerald Thaler)
• [35.14] How does the C++ keyword export help with template linker errors?
  (fixed a bug in the last paragraph by changing NO_EXPORT_KEYWORD to USE_EXPORT_KEYWORD thanks to Luís Bruno)
• [35.19] Why am I getting errors when my template-derived-class uses a member it inherits from its template-base-class?
  (wordsmithed, clarified)
• [35.20] Can the previous problem hurt me silently? Is it possible that the compiler will silently generate the wrong code?
  (rewrote to include non-dependent type-names in addition to non-dependent member-names thanks to a discussion with Victor Bazarov)
• [40.3] Are there any pretty-printers that reformat C++ source code?
  (added "ProFactor StyleManager" thanks to Matt Godbolt)

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2 New FAQs:

• [4.14] What updates were made for the 03/06 release?
• [29.18] Why is cos(x) != cos(y) even though x == y? (Or sine or tangent or log or just about any other floating point computation)

8 Changed FAQs:

• [13.9] What are some guidelines / "rules of thumb" for overloading operators?
  (clarified point #7)
• [13.12] I still don't get it. Why shouldn't my Matrix class's interface look like an array-of-array?
  (fixed call to Matrix::Row ctor thanks to John Pavel)
• [17.14] But MFC seems to encourage the use of catch-by-pointer; should I do the same?
  (changed rand() to rand() >> 8 to (typically) improve the period of lowest 2 bits)
• [23.3] Should I use protected virtuals instead of public virtuals?
  (connected in the (previously named) "Public Overloaded Non-Virtuals Call Protected Non-Overloaded Virtuals" Idiom)
• [34.3] Is the storage for a std::vector<T> guaranteed to be contiguous?
  (added new subject-index entries that point to this FAQ thanks to Peter Koch)
• [35.8] Huh? Can you provide an example of template specialization that doesn't use foo and bar?
  (rewrote the last paragraph for clarity)
• [35.9] But most of the code in my template function is the same; is there some way to get the benefits of template specialization without duplicating all that source code?
  (reworked the code-commentary to improve clarity)
• [38.1] Where can I download a free C++ compiler?
  (added the compilers.net site thanks to Dejan Milicic plus added Microsoft's command-line compiler)

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9 New FAQs:

• [4.15] What updates were made for the 10/05 release?
• [23.3] Should I use protected virtuals instead of public virtuals?
  (thanks to a question from Neil Morgenstern)
• [23.4] When should someone use private virtuals?
  (thanks to a question from Neil Morgenstern)
• [35.7] My template function does something special when the template type T is int or std::string; how do I write my template so it uses the special code when T is one of those specific types?
  (thanks to Victor Bazarov)
• [35.8] Huh? Can you provide an example of template specialization that doesn't use foo and bar?
• [35.9] But most of the code in my template function is the same; is there some way to get the benefits of template specialization without duplicating all that source code?
  (thanks to Victor Bazarov)
• [35.10] All those templates and template specializations must slow down my program, right?
  (thanks to Victor Bazarov)
• [35.11] So templates are overloading, right?
  (thanks to Victor Bazarov)
• [35.14] How does the C++ keyword export help with template linker errors?
  (thanks to Yechiel Kimchi )

4 Changed FAQs:

• [6.13] Where can I get a copy of the ANSI/ISO C++ standard?
  (added another link to the C++ Standard thanks to Andrew Koenig)
• [35.12] Why can't I separate the definition of my templates class from its declaration and put it inside a .cpp file?
  (added some caveats and pointed people to the newly added FAQ on the export keyword)
• [35.13] How can I avoid linker errors with my template functions?
  (added some caveats and pointed people to the newly added FAQ on the export keyword)
• [39.6] What should be done with macros that need to paste two tokens together?
  (capitalized macro name2() to NAME2() to prevent name-collisions)

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1 New FAQs:

• [4.16] What updates were made for the 07/05 release?

3 Changed FAQs:

• [5.1] What does IMHO mean? (or IMO, IMNSHO, FWIW, OTOH, etc.)?
  (added SSO thanks to Andrei Alexandrescu)
• [10.5] Which constructor gets called when I create an array of Fred objects?
  (wordsmithed thanks to Vangelis Katsikaros)
• [28.6] What are some best-of-breed C++ legality guides?
  (updated the information about C++ Primer to reflect its fourth edition thanks to Andrew Koenig)

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2 New FAQs:

• [4.17] What updates were made for the 06/05 release?
• [27.5] Should I use using namespace std in my code?
  (thanks to a suggestion from Victor Bazarov)

7 Changed FAQs:

• [2.4] Where can I find the C++ FAQ translated into Bosnian / Serbian / Croatian?
  (fixed misspelling in "Croatian" thanks to Ivan Lashutin)
• [6.3] What's the big deal with OO?
  (fixed a typo thanks to Allan W)
• [6.16] Will I sometimes use any so-called "evil" constructs?
  (improved the tooltip ("bubble help-text") that pops up on "milquetoast")
• [6.18] What should I tell people who complain that the word "FAQ" is misleading, that it emphasizes the questions rather than the answers, and that we should all start using a different acronym?
  (corrected a misspelling)
• [8.6] When should I use references, and when should I use pointers?
  (expounded on "sentinel reference" thanks to Vangelis Katsikaros)
• [10.6] Should my constructors use "initialization lists" or "assignment"?
  (fixed a typo thanks to Vangelis Katsikaros)
• [18.9] What does "const X* x" mean?
  (added a paragraph about making sure nobody confuses Fred const* x and Fred* const x)

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Generic changes:

• Reworked the lists of mirror sites and translations on the opening page.

4 New FAQs:

• [2.4] Where can I find the C++ FAQ translated into Bosnian / Serbian / Croatian?
  (with much thanks to translator Zaharije Pasalic)
• [4.18] What updates were made for the 05/05 release?
• [13.12] I still don't get it. Why shouldn't my Matrix class's interface look like an array-of-array?
• [25.15] What is the exact order of destructors in a multiple and/or virtual inheritance situation?
  (thanks to a question from Noam)

4 Changed FAQs:

• [13.10] How do I create a subscript operator for a Matrix class?
  (added a pointer to the FAQ containing the rationale)
• [13.11] Why shouldn't my Matrix class's interface look like an array-of-array?
  (added an indication that the outer operator[] can return a (shudder) raw pointer to the zeroth element of the corresponding row)
• [35.20] Can the previous problem hurt me silently? Is it possible that the compiler will silently generate the wrong code?
  (fixed a typo thanks to Assaf Lavie)
• [38.5] Where can I get information about the C++ compiler from {Borland, IBM, Microsoft, Sun, etc.}?
  (updated the link to Microsoft Visual C++ thanks to Amos Shapira)

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5 New FAQs:

• [4.19] What updates were made for the 04/05 release?
• [6.4] What's the big deal with generic programming?
  (thanks to a suggestion from Ioannis Vranos)
• [6.18] What should I tell people who complain that the word "FAQ" is misleading, that it emphasizes the questions rather than the answers, and that we should all start using a different acronym?
• [17.7] I have too many try blocks; what can I do about it?
  (thanks to a question from Gustavo A. Baratto)
• [29.21] What other "newbie" guides are there for me?
  (thanks to Alf Steinbach for putting together The Correct C++ Tutorial)

18 Changed FAQs:

• [5.1] What does IMHO mean? (or IMO, IMNSHO, FWIW, OTOH, etc.)?
  (added the Acronym Finder thanks to Jarno Lamberg)
• [6.2] Is C++ a perfect language?
  (made it clear that "warts" are common to all languages and tools)
• [6.3] What's the big deal with OO?
  (rewrote third paragraph to reflect the reality that "as a better C" is sometimes intentional)
• [6.7] How long does it take to learn OO/C++?
  (wordsmithed)
• [6.9] Are virtual functions (dynamic binding) central to OO/C++?
  (added the last paragraph to clarify relationship between virtual functions and generic programming)
• [8.8] What is a handle to an object? Is it a pointer? Is it a reference? Is it a pointer-to-a-pointer? What is it?
  (slight wordsmithing thanks to Steve Fábián)
• [16.22] How do I do simple reference counting?
  (fixed a subtle bug in the assignment operator thanks to Gianni Mariani)
• [16.23] How do I provide reference counting with copy-on-write semantics?
  (fixed a subtle bug in the assignment operator thanks to Gianni Mariani)
• [16.24] How do I provide reference counting with copy-on-write semantics for a hierarchy of classes?
  (fixed a subtle bug in the assignment operator thanks to Gianni Mariani)
• [17.16] How do I throw polymorphically?
  (fixed a typo thanks to Lyle Ziegelmiller)
• [23.6] Okay, but is there a way to simulate that behavior as if dynamic binding worked on the this object within my base class's constructor?
  (clarified that this is called the "Dynamic Binding During Initialization Idiom")
• [23.7] I'm getting the same mess with destructors: calling a virtual on my this object from my base class's destructor ends up ignoring the override in the derived class; what's going on?
  (fixed the cross-references thanks to Alf Steinbach and Michal Bartoszkiewicz)
• [27.13] Are there any other sources of coding standards?
  (added www.codingstandard.com/ thanks to Robert Buckley)
• [29.5] What are the criteria for choosing between short / int / long data types?
  (added the disclaimer that <stdint.h> is not guaranteed to include int32_t thanks to Padmanabhan V. Karthic)
• [29.15] What is this NaN thing?
  (added recommendation to use isnan() where available thanks to Stefan Ring)
• [35.19] Why am I getting errors when my template-derived-class uses a member it inherits from its template-base-class?
  (fixed a typo thanks to Neil Falwasser; while I was in there I rewrote most of it)
• [35.20] Can the previous problem hurt me silently? Is it possible that the compiler will silently generate the wrong code?
  (added a cross-reference and did some wordsmithing)
• [39.13] What special considerations are needed when forward declarations are used with inline functions?
  (added the inline-below-Barney workaround thanks to Ganesh Sundaram, plus the nested-classes workaround; rewrote the "workarounds" paragraph)

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9 New FAQs:

• [2.9] Where can I find the C++ FAQ translated into Greek?
  (with much thanks to translator Vangelis Katsikaros)
• [2.15] Where can I find the C++ FAQ translated into Turkish?
  (with much thanks to translator Doruk Caner)
• [4.20] What updates were made for the 03/05 release?
• [16.2] Is it safe to delete the same pointer twice?
  (promted by a question from Hans Van den Eynden)
• [18.11] What's the relationship between a return-by-reference and a const member function?
• [18.12] What's the deal with "const-overloading"?
• [20.4] What happens in the hardware when I call a virtual function? How many layers of indirection are there? How much overhead is there?
• [20.5] How can a member function in my derived class call the same function from its base class?
• [23.7] I'm getting the same mess with destructors: calling a virtual on my this object from my base class's destructor ends up ignoring the override in the derived class; what's going on?

23 Changed FAQs:

• [5.9] Which newsgroup should I post my questions?
  (added microsoft.public.dotnet.languages.vc thanks to Ioannis Vranos)
• [5.10] Should I post job advertisements and/or resumés on comp.lang.c++?
  (duplicated the attribution that was in the recent changes section thanks to Daryle Walker)
• [5.11] What if I really need a job; should I post my resumé on comp.lang.c++?
  (duplicated the attribution that was in the recent changes section thanks to Daryle Walker)
• [6.13] Where can I get a copy of the ANSI/ISO C++ standard?
  (updated the Barnes & Noble URL)
• [10.5] Which constructor gets called when I create an array of Fred objects?
  (added the paragraph on placement-new thanks to Alf P. Steinbach; rewrote the other examples)
• [10.6] Should my constructors use "initialization lists" or "assignment"?
  (added "non-static reference" to the list of data members that must appear within an initialization list thanks to Daryle Walker)
• [10.15] How do I prevent the "static initialization order fiasco"?
  (changed *.hpp to *.h)
• [10.16] Why doesn't the construct-on-first-use idiom use a static object instead of a static pointer?
  (changed *.hpp to *.h)
• [10.17] How do I prevent the "static initialization order fiasco" for my static data members?
  (changed *.hpp to *.h)
• [12.1] What is "self assignment"?
  (changed *.hpp to *.h)
• [16.18] But the above Matrix class is specific to Fred! Isn't there a way to make it generic?
  (changed *.hpp to *.h)
• [19.8] I've been told to never use protected data, and instead to always use private data with protected access functions. Is that a good rule?
  (added the goal of providing a coherent/opaque interface to the goals of data hiding thanks to Yechiel Kimchi )
• [23.1] Is it okay for a non-virtual function of the base class to call a virtual function?
  (changed *.hpp to *.h)
• [23.9] What's the meaning of, Warning: Derived::f(char) hides Base::f(double)?
  (added the paragraph on "hiding happens when you have a derived-pointer, not when you have a base-pointer" thanks to Daniel Kabs)
• [26.6] I'm sooooo confused. Would you please go over the rules about bytes, chars, and characters one more time?
  (fixed a spelling error thanks to Daryle Walker)
• [26.10] Can I define an operator overload that works with built-in / intrinsic / primitive types?
  (added "or enumeration type" to the first sentence thanks to Daryle Walker)
• [29.20] If an enumeration type is distinct from any other type, what good is it? What can you do with it?
  (added the caveat on the last line of code thanks to Daryle Walker)
• [32.1] What do I need to know when mixing C and C++ code?
  (added a caveat about some of the requirements depending on your compiler-vendor thanks to Mitchell Charity)
• [34.3] Is the storage for a std::vector<T> guaranteed to be contiguous?
  (changed &v[0] to v.empty() ? NULL : &v[0] thanks to David Hilsee)
• [35.15] How can I avoid linker errors with my template classes?
  (fixed a bug by changing template Foo<int> to template class Foo<int> thanks to alert readers Eric Gorr and Patrick Guio)
• [37.9] Where can I get tons and tons of more information on C++ class libraries?
  (fixed the URL to www.mathtools.net/C_C__ thanks to Daryle Walker)
• [39.7] Why can't the compiler find my header file in #include "c:\test.h" ?
  (changed *.hpp to *.h)
• [40.3] Are there any pretty-printers that reformat C++ source code?
  (fixed the URL to C++2LaTeX thanks to Daryle Walker and Nicolás Conde)

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Generic changes:

• Split the section on Containers and Templates into a section on Containers and a section on Templates.

6 New FAQs:

• [4.21] What updates were made for the 02/05 release?
• [9.9] With inline member functions that are defined outside the class, is it best to put the inline keyword next to the declaration within the class body, next to the definition outside the class body, or both?
• [10.9] Does return-by-value mean extra copies and extra overhead?
• [13.8] Okay, that tells me the operators I can override; which operators should I override?
  (thanks to Conrad Weisert for suggesting the topic)
• [13.9] What are some guidelines / "rules of thumb" for overloading operators?
• [33.14] Can you make functionoids faster than normal function calls?
  (thanks to a suggestion from Padmanabhan V. Karthic)

24 Changed FAQs:

• [5.9] Which newsgroup should I post my questions?
  (added a link to TechiWarehouse thanks to Adam Fisher)
• [9.3] Do inline functions improve performance?
  (added two bullets on cache misses thanks to a suggestion from Tom Brown)
• [10.6] Should my constructors use "initialization lists" or "assignment"?
  (added an "or when" and a cross reference to the last paragraph, plus fixed some grammar, thanks to Padmanabhan V. Karthic)
• [10.8] What is the "Named Constructor Idiom"?
  (added the last paragraph to discuss the return-by-value optimization thanks to a question from Can Isin)
• [10.20] What is the "Named Parameter Idiom"?
  (changed friend File; to friend class File; thanks to Mehri and Padmanabhan V. Karthic)
• [10.21] Why am I getting an error after declaring a Foo object via Foo x(Bar())?
  (added the alternate syntax Foo x = Bar(); thanks to a suggestion from Mike Dunn)
• [13.13] Should I design my classes from the outside (interfaces first) or from the inside (data first)?
  (changed friend LinkedList; to friend class LinkedList;, and similarly with LinkedListIterator, thanks to Padmanabhan V. Karthic)
• [16.19] What's another way to build a Matrix template?
  (added some pros/cons (mostly pros) thanks to a suggestion from Padmanabhan V. Karthic)
• [16.22] How do I do simple reference counting?
  (changed friend FredPtr; to friend class FredPtr; thanks to Padmanabhan V. Karthic)
• [16.24] How do I provide reference counting with copy-on-write semantics for a hierarchy of classes?
  (changed friend Fred; to friend class Fred; thanks to Padmanabhan V. Karthic)
• [17.6] Exception handling seems to make my life more difficult; clearly I'm not the problem, am I??
  (rewrote the last bullet thanks to a critique of the old wording from Jan Ploski)
• [17.13] What should I catch?
  (fixed a grammatical error thanks to Padmanabhan V. Karthic)
• [18.15] Why does the compiler allow me to change an int after I've pointed at it with a int const*?
  (initialized variable x in main() thanks to Yechiel Kimchi )
• [27.13] Are there any other sources of coding standards?
  (hoisted the Sutter/Alexandrescu book out to its proper, primary place; also added (thanks to Kevlin Henney) links to and insights about Elemtel and Industrial Strength C++)
• [29.5] What are the criteria for choosing between short / int / long data types?
  (added the disclaimer that <stdint.h> is not part of the C++ standard and might not be supplied by your compiler vendor thanks to Padmanabhan V. Karthic)
• [29.19] What is the type of an enumeration such as enum Color? Is it of type int?
  (fixed a typo thanks to Surendra Phadke and Brandon Forehand)
• [30.5] What are the practical consequences of differences in Smalltalk/C++ inheritance?
  (fixed the spelling of Maserati thanks to Alessandro/Gruppo Visione)
• [33.2] How do I pass a pointer-to-member-function to a signal handler, X event callback, system call that starts a thread/task, etc?
  (fixed a grammatical error thanks to Padmanabhan V. Karthic)
• [33.5] How can I avoid syntax errors when creating pointers to members?
  (added return value (int ans = ...) to make the sample-code more illustrative thanks to Pete Brunet)
• [33.6] How can I avoid syntax errors when calling a member function using a pointer-to-member-function?
  (added return value (int ans = ...) to make the sample-code more illustrative thanks to Pete Brunet)
• [33.13] What the heck is a functionoid, and why would I use one?
  (added a virtual dtor thanks to Marcus; added parameters to doit() thanks to Dirk Bonekaemper; made the dtor pure virtual as an optimization)
• [35.19] Why am I getting errors when my template-derived-class uses a member it inherits from its template-base-class?
  (added public: thanks to Alexander Kamotsky and Leonard "SoulSkorpion" Frankel and Stefan Näwe; fixed a grammatical error thanks to Val Kartchner)
• [39.4] What should be done with macros that contain if?
  (clarified why we use the (void)0 part thanks to a suggestion from Padmanabhan V. Karthic)
• [40.1] How can I generate HTML documentation for my classes? Does C++ have anything similar to javadoc?
  (updated the link to www.robertnz.net/cpp_site.html#Documentation thanks to Robert Davies and Peter Kammer)

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Generic changes:

• In an attempt to stem the inexorable tide of spam, I've obfuscated the email address of anyone who has contributed to the FAQ. The email addresses are easy to decode, e.g., (NOSPAM)marshall(DASH)cline(AT)parashift(DOT)com becomes marshall-cline@parashift.com, though hopefully the spam-bots won't bother (yea right).

3 New FAQs:

• [4.22] What updates were made for the 12/04 release?
• [10.21] Why am I getting an error after declaring a Foo object via Foo x(Bar())?
  (thanks to James Kanze)
• [17.6] Exception handling seems to make my life more difficult; clearly I'm not the problem, am I??
  (thanks to an email conversation with Bob Bell)

9 Changed FAQs:

• [2.2] What happened to the one-click-download option?
  (added request to stop emailing me requests to send it manually)
• [5.2] How do I get other people to do my homework problem for me?
  (duplicated the "Jack Klein" attribution that was in the recent changes section thanks to Daryle Walker)
• [6.5] Is C++ better than Ada? (or Visual Basic, C, FORTRAN, Pascal, Smalltalk, or any other language?)
  (fixed a spelling error thanks to Gerriet Backer)
• [21.8] But I have a Ph.D. in Mathematics, and I'm sure a Circle is a kind of an Ellipse! Does this mean Marshall Cline is stupid? Or that C++ is stupid? Or that OO is stupid?
  (added the paragraph on constant Ellipses thanks to Luke Palmer)
• [23.9] What's the meaning of, Warning: Derived::f(char) hides Base::f(double)?
  (included a new example, changed the parameter types so the behavior seems more bizarre/ominous, and added a note about warnings not being standardized, thanks to Daniel Kabs)
• [25.3] So there are times when multiple inheritance isn't bad?!??
  (fixed a typo thanks to Sumit Rajan)
• [27.1] What are some good C++ coding standards?
  (added last few sentences on the Sutter/Alexandrescu book)
• [27.13] Are there any other sources of coding standards?
  (added a bullet on the Sutter/Alexandrescu book)
• [28.4] Should I buy one book, or several?
  (added last few sentences recommending purchase of a coding-standards book)

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Polish translation:

• The Polish translation of the C++ FAQ is now available thanks to the hard work of translators Tomek Bywalec, Bartek Krzemien and Janek Pustelnik. The translation isn't finished, but the translators deserve congratulations and thanks for what they've done so far.

16 New FAQs:

• [2.11] Where can I find the C++ FAQ translated into Polish?
  (with much thanks to translators Tomek Bywalec, Bartek Krzemien and Janek Pustelnik)
• [4.23] What updates were made for the 06/04 release?
• [6.17] Is it important to know the technical definition of "good OO"? Of "good class design"?
• [17.12] What should I throw?
  (thanks to Carl Daniel)
• [17.13] What should I catch?
  (thanks to Carl Daniel)
• [17.14] But MFC seems to encourage the use of catch-by-pointer; should I do the same?
  (thanks to Carl Daniel)
• [17.15] What does throw; (without an exception object after the throw keyword) mean? Where would I use it?
  (thanks to Carl Daniel)
• [17.16] How do I throw polymorphically?
  (thanks to Carl Daniel)
• [17.17] When I throw this object, how many times will it be copied?
  (thanks to Carl Daniel)
• [33.12] I need something like function-pointers, but with more flexibility and/or thread-safety; is there another way?
• [33.13] What the heck is a functionoid, and why would I use one?
  (thanks to a question from Christian Cuvier)
• [35.17] How can any human hope to understand these overly verbose template-based error messages?
  (thanks to gentle pestering from Leor Zolman)
• [35.19] Why am I getting errors when my template-derived-class uses a member it inherits from its template-base-class?
  (thanks to Daveed Vandevoorde)
• [35.20] Can the previous problem hurt me silently? Is it possible that the compiler will silently generate the wrong code?
  (thanks to Daveed Vandevoorde)
• [39.15] Why do some people think x = ++y + y++ is bad?
• [39.16] What's the deal with "sequence points"?

32 Changed FAQs:

• [2.6] Where can I find the C++ FAQ translated into Chinese?
  (updated the URL for the GB-encoded translation thanks to Imron Alston)
• [6.5] Is C++ better than Ada? (or Visual Basic, C, FORTRAN, Pascal, Smalltalk, or any other language?)
  (added to the last paragraph to make it stronger(!!))
• [6.13] Where can I get a copy of the ANSI/ISO C++ standard?
  (rewrote from scratch, thanks to comments and corrections from Petter Häggholm, Lars Christensen, Pieter Van Dyck and Jim Fischer)
• [6.15] What does the FAQ mean by "such and such is evil"?
  (changed "such-in-such" to "such and such" thanks to Darren Frith and Simon OLeary)
• [8.4] What does object.method1().method2() mean?
  (removed a couple superfluous ")"s)
• [10.3] Can one constructor of a class call another constructor of the same class to initialize the this object?
  (added a strong statement against using placement new in this situation thanks to questions from Marc Page and Steve Peters)
• [10.6] Should my constructors use "initialization lists" or "assignment"?
  (fixed a (subtle!) miswording in the second paragraph thanks to Tomek Bywalec, Bartek Krzemien and Tian Yu; added the stuff on exceptions (see last paragraph) thanks to Alf Steinbach)
• [10.20] What is the "Named Parameter Idiom"?
  (added a bunch more example code and clarified the explanation of class OpenFile thanks to Tomek Bywalec and Bartek Krzemien)
• [12.1] What is "self assignment"?
  (fixed an error in the code-comments thanks to Jonathan Mcdougall)
• [13.10] How do I create a subscript operator for a Matrix class?
  (fixed a typo thanks to Doug Schwartz)
• [15.1] Why should I use <iostream> instead of the traditional <cstdio>?
  (removed a superfluous ")")
• [15.9] But shouldn't I always use a printOn() method rather than a friend function?
  (removed a superfluous ")")
• [15.17] How can I tell {if a key, which key} was pressed before the user presses the ENTER key?
  (updated the URL thanks to Sampath Patnala)
• [15.18] How can I make it so keys pressed by users are not echoed on the screen?
  (fixed the title thanks to Todd Catelotti)
• [16.6] Do I need to check for NULL after p = new Fred()?
  (added a caveat for MSVC++ thanks to Graham Knap)
• [20.8] What is a "virtual constructor"?
  (rewrote the last paragraph for clarity)
• [21.2] Converting Derived* → Base* works OK; why doesn't Derived** → Base** work?
  (fixed a grammatical error thanks to Philip S Tellis)
• [22.5] How do you define a copy constructor or assignment operator for a class that contains a pointer to a (abstract) base class?
  (added a "contract" to the Fred ctor thanks to Bo Majewski; changed the return types in the derived classes to exploit covariant return types thanks to Dan Raviv)
• [23.11] How can I set up my class so it won't be inherited from?
  (fixed a bug in the friend declaration, renamed the classes to Fred and FredBase, and general wordsmithing)
• [28.7] What are some best-of-breed C++ programming-by-example guides?
  (added details about Musser and Saini thanks to Randy Sherman)
• [29.5] What are the criteria for choosing between short / int / long data types?
  (added stuff about <stdint.h> thanks to Oliver Kellogg)
• [29.19] What is the type of an enumeration such as enum Color? Is it of type int?
  (added the caveat about converting only valid integers to enumerations thanks to Mike Radford)
• [33.2] How do I pass a pointer-to-member-function to a signal handler, X event callback, system call that starts a thread/task, etc?
  (added caveat about using extern "C" non-member function thanks to Rolf Magnus)
• [33.4] Why am I having trouble taking the address of a C++ function?
  (rewrote the opening paragraph to give a better explanation of the "short answer")
• [35.13] How can I avoid linker errors with my template functions?
  (added a note about the export keyword thanks to Greg Comeau)
• [35.15] How can I avoid linker errors with my template classes?
  (added a note about the export keyword thanks to Greg Comeau)
• [35.16] Why do I get linker errors when I use template friends?
  (added the required <> within the friend declaration thanks to Christophe Barbe; added the "define it within the class body" approach thanks to Frode Angell-Petersen AKA Sprudling)
• [36.10] How do I serialize objects that contain pointers to other objects, but those pointers form a tree with no cycles and only "trivial" joins?
  (fixed some spelling errors thanks to Steve Fallows)
• [38.13] Is it possible to convert C++ to C?
  (added LLVM thanks to Chris Sabre)
• [39.4] What should be done with macros that contain if?
  (modified the primary solution to include (void)0, and thanks to Erik Haugen and Mike Morearty, added some pros/cons commentary to the secondary solution; plus did some general wordsmithing)
• [39.5] What should be done with macros that have multiple lines?
  (modified the primary solution to include (void)0, and thanks to Erik Haugen and Mike Morearty, added some pros/cons commentary to the secondary solution; plus did some general wordsmithing)
• [39.7] Why can't the compiler find my header file in #include "c:\test.h" ?
  (softened the wording to reflect the difference between header-names and string-literals thanks to Michiel Salters)

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1 New FAQs:

• [4.24] What updates were made for the 08/03 release?

10 Changed FAQs:

• [2.2] What happened to the one-click-download option?
  (disabled due to spam)
• [6.16] Will I sometimes use any so-called "evil" constructs?
  (changed "effect" to "affect" thanks to J.K. Lowden)
• [10.3] Can one constructor of a class call another constructor of the same class to initialize the this object?
  (fixed typo thanks to Charles Daniels)
• [13.10] How do I create a subscript operator for a Matrix class?
  (fixed a memory leak thanks to Paladin)
• [16.18] But the above Matrix class is specific to Fred! Isn't there a way to make it generic?
  (plugged a memory leak in the ctor)
• [16.22] How do I do simple reference counting?
  (fixed a typo thanks to Lee Graham)
• [29.5] What are the criteria for choosing between short / int / long data types?
  (changed "at least 2 bytes" to "at least 16 bits" (and fixed other similar bone-headed mistakes) thanks to Peter Nilsson)
• [36.11] How do I serialize objects that contain pointers to other objects, and those pointers form a graph that might have cycles or non-trivial joins?
  (fixed a spelling error)
• [39.3] Can I templatize the above functions so they work with other types?
  (fixed a bug (type_info<T>::name() → typeid(x).name()) thanks to Thomas Tutone)
• [39.8] What are the C++ scoping rules for for loops?
  (fixed typo thanks to Henrik Torkelund)

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2 New FAQs:

• [4.25] What updates were made for the 06/03 release?
• [35.16] Why do I get linker errors when I use template friends?
  (with lots of input from Carl Daniel)

13 Changed FAQs:

• [5.1] What does IMHO mean? (or IMO, IMNSHO, FWIW, OTOH, etc.)?
  (added HAND, YHBT and YHL)
• [10.14] What's the "static initialization order fiasco"?
  (wordsmithed)
• [16.18] But the above Matrix class is specific to Fred! Isn't there a way to make it generic?
  (changed class to typename in template declarations)
• [16.19] What's another way to build a Matrix template?
  (changed class to typename in template declarations)
• [32.8] How can I pass an object of a C++ class to/from a C function?
  (added the last two paragraphs)
• [35.2] What's the syntax / semantics for a "class template"?
  (changed class to typename in template declarations)
• [35.3] What's the syntax / semantics for a "function template"?
  (changed class to typename in template declarations)
• [35.4] How do I explicitly select which version of a function template should get called?
  (changed class to typename in template declarations)
• [35.12] Why can't I separate the definition of my templates class from its declaration and put it inside a .cpp file?
  (changed class to typename in template declarations)
• [35.13] How can I avoid linker errors with my template functions?
  (changed class to typename in template declarations)
• [35.15] How can I avoid linker errors with my template classes?
  (changed class to typename in template declarations)
• [37.3] How can I find a Fred object in an STL container of Fred* such as std::vector<Fred*>?
  (changed class to typename in template declarations)
• [39.3] Can I templatize the above functions so they work with other types?
  (changed class to typename in template declarations)

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1 New FAQs:

• [4.26] What updates were made for the 05/03 release?

5 Changed FAQs:

• [9.4] How can inline functions help with the tradeoff of safety vs. speed?
  (fixed a misspelling)
• [16.17] But the previous FAQ's code is SOOOO tricky and error prone! Isn't there a simpler way?
  (fixed a memory leak in the ctor when nrows or ncols was zero thanks to Chris Carton)
• [16.24] How do I provide reference counting with copy-on-write semantics for a hierarchy of classes?
  (fixed a subtle bug in the code thanks to James Megquier)
• [25.12] What special considerations do I need to know about when I inherit from a class that uses virtual inheritance?
  (fixed spelling error ("becuase") thanks to Olga Colombo)
• [37.4] Where can I get help on how to use STL?
  (added SGI's STL Programmer's guide)

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1 New FAQs:

• [4.27] What updates were made for the 04/03 release?

13 Changed FAQs:

• [3.1] Is there a C++ FAQ Book in addition to this on-line C++ FAQ?
  (rewrote, added several bookstores, and updated the URL for the source code)
• [7.5] How does C++ help with the tradeoff of safety vs. usability?
  (clarified that it is data declared as static at file-scope that is deprecated)
• [9.3] Do inline functions improve performance?
  (rewrote the "can cause thrashing" bullet thanks to Zarius Tularial; also reworded throughout to strengthen the points)
• [16.19] What's another way to build a Matrix template?
  (added methods nrows() and ncols() thanks to Christopher Mackie and Paolo Copello; inserted std:: in front of vector a few times thanks to Francisco Osorio G)
• [20.8] What is a "virtual constructor"?
  (added a note that MS VC++ 7.0 handles covariant return types thanks to Paolo Copello)
• [23.11] How can I set up my class so it won't be inherited from?
  (added the paragraph that the virtual inheritance approach might increase sizeof(Leaf))
• [26.6] I'm sooooo confused. Would you please go over the rules about bytes, chars, and characters one more time?
  (reworded the fifth bullet (so it doesn't use "effect") thanks to Mal Morrow and Chuck Pahlmeyer)
• [26.7] What is a "POD type"?
  (fixed a misspelling (equialent → equivalent) thanks to Mal Morrow)
• [34.3] Is the storage for a std::vector<T> guaranteed to be contiguous?
  (fixed a couple of typos in the last two paragraphs thanks to Dean Stanton)
• [37.2] Where can I get a copy of "STL"?
  (fixed the URL for the SGI implementation thanks to Jeremy Bishop)
• [38.2] Where can I get more information on using MFC and Visual C++?
  (rewrote with updated URLs thanks to Paolo Copello)
• [39.8] What are the C++ scoping rules for for loops?
  (replaced the pithy one-liner at the very beginning and corrected another typo thanks to Mans Gunnarsson)
• [40.3] Are there any pretty-printers that reformat C++ source code?
  (fixed the URL for C++2LaTeX thanks to Vinay Kumar Nallamothu)

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1 New FAQs:

• [4.28] What updates were made for the 03/03 release?

4 Changed FAQs:

• [5.9] Which newsgroup should I post my questions?
  (clarified that "the C++ language" means the language defined by the ISO/ANSI C++ Standard thanks to Victor Bazarov)
• [18.8] What does "const X& x" mean?
  (rewrote to make it even clearer that this is a business decision, and that the outcome will be different in different organizations)
• [18.9] What does "const X* x" mean?
  (rewrote to make it even clearer that this is a business decision, and that the outcome will be different in different organizations)
• [25.6] Is there a simple way to visualize all these tradeoffs?
  (fixed a typo ("calss" → "class") thanks to John Ericson)

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4 New FAQs:

• [4.29] What updates were made for the 02/03 release?
• [25.8] What is the "dreaded diamond"?
  (thanks to Carl Daniel)
• [25.9] Where in a hierarchy should I use virtual inheritance?
  (thanks to Carl Daniel)
• [25.10] What does it mean to "delegate to a sister class" via virtual inheritance?
  (thanks to Carl Daniel)

12 Changed FAQs:

• [5.1] What does IMHO mean? (or IMO, IMNSHO, FWIW, OTOH, etc.)?
  (added PEBCAC and PEBCAK thanks to William L. Thomson Jr.)
• [6.15] What does the FAQ mean by "such and such is evil"?
  (fixed a typo in second to last paragraph thanks to Joe Sewell)
• [15.3] How can I get std::cin to skip invalid input characters?
  (changed ignore()'s first parameter from int to std::streamsize thanks to Mike Wahler)
• [15.6] Why is my program ignoring my input request after the first iteration?
  (changed ignore()'s first parameter from int to std::streamsize thanks to Mike Wahler)
• [17.8] How can I handle a constructor that fails?
  (rewrote to make a stronger case against "zombie" objects)
• [18.17] Why am I getting an error converting a Foo** → Foo const**?
  (fixed a bug in the code (*q vs. *p) thanks to Richard van Wegen)
• [19.9] Okay, so exactly how should I decide whether to build a "protected interface"?
  (fixed a couple of typos thanks to Joe Sewell)
• [23.9] What's the meaning of, Warning: Derived::f(char) hides Base::f(double)?
  (added the last paragraph thanks to Carl Daniel)
• [23.11] How can I set up my class so it won't be inherited from?
  (added the virtual base class technique thanks to Carl Daniel)
• [25.11] What special considerations do I need to know about when I use virtual inheritance?
  (updated thanks to Carl Daniel)
• [25.12] What special considerations do I need to know about when I inherit from a class that uses virtual inheritance?
  (updated thanks to Carl Daniel)
• [33.2] How do I pass a pointer-to-member-function to a signal handler, X event callback, system call that starts a thread/task, etc?
  (fixed a typo in the name "The X Window System" thanks to Maurizio Colucci)

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9 New FAQs:

• [4.30] What updates were made for the 01/03 release?
• [15.3] How can I get std::cin to skip invalid input characters?
  (thanks to Mike Wahler and Sam Dutton)
• [18.9] What does "const X* x" mean?
• [18.17] Why am I getting an error converting a Foo** → Foo const**?
  (thanks to a question from Stephen Tashiro)
• [34.3] Is the storage for a std::vector<T> guaranteed to be contiguous?
  (thanks to Daveed Vandevoorde)
• [36.3] How do I decide whether to serialize to human-readable ("text") or non-human-readable ("binary") format?
• [36.4] How do I serialize/unserialize simple types like numbers, characters, strings, etc.?
• [36.5] How exactly do I read/write simple types in human-readable ("text") format?
• [36.6] How exactly do I read/write simple types in non-human-readable ("binary") format?
  (fixed a typo (indent vs. intent) and added a few clarifications thanks to Troy S)

16 Changed FAQs:

• [1.5] Trademarks
  (added comment about non-commercial sites being exempt from trademark dilution laws)
• [2.1] Where's the closest mirror site to access this document?
  (added URL to the mirror site in Israel thanks to Yechiel Kimchi )
• [6.16] Will I sometimes use any so-called "evil" constructs?
  (added "'Think' is not a four-letter word" thanks to Dave Power)
• [13.14] How can I overload the prefix and postfix forms of operators ++ and --?
  (fixed typo in title thanks to Kevin Goodsell)
• [18.8] What does "const X& x" mean?
  (added the paragraph starting "Note: you'll have to overcome a certain amount of inertia...")
• [21.2] Converting Derived* → Base* works OK; why doesn't Derived** → Base** work?
  (wordsmithed and clarified)
• [21.6] Is a Circle a kind-of an Ellipse?
  (strengthened the wording)
• [21.7] Are there other options to the "Circle is/isnot kind-of Ellipse" dilemma?
  (strengthened the wording)
• [21.8] But I have a Ph.D. in Mathematics, and I'm sure a Circle is a kind of an Ellipse! Does this mean Marshall Cline is stupid? Or that C++ is stupid? Or that OO is stupid?
  (strengthened the wording)
• [29.17] Why doesn't my floating-point comparison work?
  (clarified the code)
• [33.2] How do I pass a pointer-to-member-function to a signal handler, X event callback, system call that starts a thread/task, etc?
  (rewrote to discuss the (typical) void* parameter on many system- and GUI-calls thanks to Ryan Melville)
• [36.2] How do I select the best serialization technique?
  (fixed a misspelling ("forth" vs. "fourth") thanks to Charles Brockman; rewrote to include cross-references to the text/binary decision and how to handle simple types)
• [36.7] How do I serialize objects that aren't part of an inheritance hierarchy and that don't contain pointers to other objects?
  (added description of sample algorithm thanks to Niall Douglas; rewrote everything else as well)
• [38.5] Where can I get information about the C++ compiler from {Borland, IBM, Microsoft, Sun, etc.}?
  (updated several links thanks to Thomas Tutone)
• [40.1] How can I generate HTML documentation for my classes? Does C++ have anything similar to javadoc?
  (added the link to PERCEPS)
• [40.3] Are there any pretty-printers that reformat C++ source code?
  (updated the URL for Source Styler)

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Big-picture changes:

• Added a new section on Multiple and Virtual Inheritance.
• Added a new section on Serialization.
• Added  New!  and  Updated!  tags on the section titles.

34 New FAQs:

• [4.31] What updates were made for the 12/02 release?
• [13.14] How can I overload the prefix and postfix forms of operators ++ and --?
  (thanks to Sandeep Grover)
• [13.15] Which is more efficient: i++ or ++i?
• [15.12] How can I open a stream in binary mode?
  (thanks to Simon Barner)
• [15.14] How can I write/read objects of my class to/from a data file?
• [15.15] How can I send objects of my class to another computer (e.g., via a socket, TCP/IP, FTP, email, a wireless link, etc.)?
• [19.8] I've been told to never use protected data, and instead to always use private data with protected access functions. Is that a good rule?
  (thanks to a question from Andrew Chan)
• [19.9] Okay, so exactly how should I decide whether to build a "protected interface"?
• [21.11] How could "it depend"??!? Aren't terms like "Circle" and "Ellipse" defined mathematically?
• [25.1] How is this section organized?
• [25.2] I've been told that I should never use multiple inheritance. Is that right?
• [25.3] So there are times when multiple inheritance isn't bad?!??
• [25.4] What are some disciplines for using multiple inheritance?
• [25.5] Can you provide an example that demonstrates the above guidelines?
• [25.6] Is there a simple way to visualize all these tradeoffs?
• [25.7] Can you give another example to illustrate the above disciplines?
• [25.11] What special considerations do I need to know about when I use virtual inheritance?
• [25.12] What special considerations do I need to know about when I inherit from a class that uses virtual inheritance?
• [25.13] What special considerations do I need to know about when I use a class that uses virtual inheritance?
• [25.14] One more time: what is the exact order of constructors in a multiple and/or virtual inheritance situation?
  (thanks to Carl Daniel)
• [33.10] Can I convert a pointer-to-member-function to a void*?
• [33.11] Can I convert a pointer-to-function to a void*?
• [35.13] How can I avoid linker errors with my template functions?
  (thanks to a suggestion by Michael Kochetkov)
• [35.15] How can I avoid linker errors with my template classes?
  (thanks to a suggestion by Michael Kochetkov)
• [36.1] What's this "serialization" thing all about?
  (thanks to a question from Stephen Tashiro)
• [36.2] How do I select the best serialization technique?
• [36.7] How do I serialize objects that aren't part of an inheritance hierarchy and that don't contain pointers to other objects?
• [36.8] How do I serialize objects that are part of an inheritance hierarchy and that don't contain pointers to other objects?
• [36.9] How do I serialize objects that contain pointers to other objects, but those pointers form a tree with no cycles and no joins?
• [36.10] How do I serialize objects that contain pointers to other objects, but those pointers form a tree with no cycles and only "trivial" joins?
• [36.11] How do I serialize objects that contain pointers to other objects, and those pointers form a graph that might have cycles or non-trivial joins?
  (thanks to a question from Stephen Tashiro)
• [36.12] Are there any caveats when serializing / unserializing objects?
• [36.13] What's all this about graphs, trees, nodes, cycles, joins, and joins at the leaves vs. internal nodes?
• [39.3] Can I templatize the above functions so they work with other types?
  (inspired by Merlyn Morgan-Graham)

21 Changed FAQs:

• [5.2] How do I get other people to do my homework problem for me?
  (added the "serious bodily harm" quote thanks to Jack Klein)
• [5.4] How can I find out about general netiquette so I don't embarrass myself?
  (added the joke/quote about top-posting)
• [6.15] What does the FAQ mean by "such and such is evil"?
  (fixed a typo in the last paragraph thanks to YaoJun)
• [10.18] Do I need to worry about the "static initialization order fiasco" for variables of built-in/intrinsic types?
  (added std:: prefix on cout thanks to Thomas Tutone)
• [13.1] What's the deal with operator overloading?
  (changed parameter types from by-value to by-reference-to-const)
• [15.13] How can I "reopen" std::cin and std::cout in binary mode?
  (removed references to DOS and OS/2)
• [15.16] Why can't I open a file in a different directory such as "..\test.dat"?
  (moved/renumbered)
• [29.3] Should I use void main() or int main()?
  (fixed parameter-order mistake thanks to Chris Young and many others)
• [29.17] Why doesn't my floating-point comparison work?
  (reworded)
• [33.2] How do I pass a pointer-to-member-function to a signal handler, X event callback, system call that starts a thread/task, etc?
  (shortened some names to make it easier to read)
• [33.5] How can I avoid syntax errors when creating pointers to members?
  (renamed the macro to all-caps)
• [33.6] How can I avoid syntax errors when calling a member function using a pointer-to-member-function?
  (renamed the macro to all-caps)
• [33.7] How do I create and use an array of pointer-to-member-function?
  (renamed the macro to all-caps)
• [35.12] Why can't I separate the definition of my templates class from its declaration and put it inside a .cpp file?
  (added the caveat at the beginning; wordsmithed throughout)
• [37.4] Where can I get help on how to use STL?
  (added Rogue Wave's STL Guide thanks to Richard van Wegen)
• [37.8] Why is my executable so large?
  (added the paragraph on debugging thanks to Richard van Wegen; rewrote the second paragraph)
• [38.1] Where can I download a free C++ compiler?
  (added several new links thanks to Thomas Tutone)
• [39.1] How do I convert a value (a number, for example) to a std::string?
  (fixed a typo in the last paragraph thanks to Alex Rutchka, rewrote the code examples to use exceptions, and moved it from the I/O section)
• [39.2] How do I convert a std::string to a number?
  (rewrote the code examples to use exceptions, added the failIfLeftoverChars, and moved it from the I/O section)
• [39.4] What should be done with macros that contain if?
  (reworded in various spots)
• [39.5] What should be done with macros that have multiple lines?
  (reworded)

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Big-picture changes:

• Hyperlinks now have "hover text" — text that most browsers show when your mouse hovers over a hyperlink (though please don't write me if your particular browser doesn't have this feature; most browsers have it but some do not).
• Added a new mirror site in Poland.
• Made things easier to find by adding lots more index-terms to the permuted subject index.

9 New FAQs:

• [4.32] What updates were made for the 09/02 release?
• [6.16] Will I sometimes use any so-called "evil" constructs?
• [9.2] What's a simple example of procedural integration?
• [15.7] Should I end my output lines with std::endl or '\n'?
  (thanks to Moshe Shimoni)
• [15.20] How can I clear the screen? Is there something like clrscr()?
• [15.21] How can I change the colors on the screen?
• [23.6] Okay, but is there a way to simulate that behavior as if dynamic binding worked on the this object within my base class's constructor?
  (thanks to Alf Steinbach for inspiration, ideas, and constructive criticism)
• [29.3] Should I use void main() or int main()?
• [29.4] Should I use f(void) or f()?
  (thanks to a question from Mario Knezovic)

32 Changed FAQs:

• [2.6] Where can I find the C++ FAQ translated into Chinese?
  (updated the URL for the Big5 encoding)
• [5.1] What does IMHO mean? (or IMO, IMNSHO, FWIW, OTOH, etc.)?
  (added PMFJI)
• [5.4] How can I find out about general netiquette so I don't embarrass myself?
  (added admonitions against top-posting, HTML/rich-text postings, attachments, "C/C++," and confusing classes with objects; also removed "include a valid email address")
• [6.9] Are virtual functions (dynamic binding) central to OO/C++?
  (minor clarifications)
• [6.14] What are some "interview questions" I could ask that would let me know if candidates really know their stuff?
  (fixed a spelling error thanks to Martin Linklater)
• [9.1] What's the deal with inline functions?
  (rewrote, adding several new points)
• [9.3] Do inline functions improve performance?
  (rewrote, added numerous new points)
• [9.5] Why should I use inline functions instead of plain old #define macros?
  (wordsmithed)
• [10.3] Can one constructor of a class call another constructor of the same class to initialize the this object?
  (rewrote for clarification thanks to Nikolai Borissov)
• [10.4] Is the default constructor for Fred always Fred::Fred()?
  (partially rewrote for clarity)
• [11.6] What if I want a local to "die" before the close } of the scope in which it was created? Can I call a destructor on a local if I really want to?
  (wordsmithed)
• [17.10] How should I handle resources if my constructors may throw exceptions?
  (added the example and the admonition to use a typedef)
• [17.11] How do I change the string-length of an array of char to prevent memory leaks even if/when someone throws an exception?
  (rewrote to clarify/strengthen)
• [18.8] What does "const X& x" mean?
  (rewrote to address the "guru approach")
• [20.7] When should my destructor be virtual?
  (rewrote)
• [21.3] Is a parking-lot-of-Car a kind-of parking-lot-of-Vehicle?
  (strengthened in several places)
• [21.8] But I have a Ph.D. in Mathematics, and I'm sure a Circle is a kind of an Ellipse! Does this mean Marshall Cline is stupid? Or that C++ is stupid? Or that OO is stupid?
  (fixed typo in first paragraph thanks to Jim Fischer)
• [21.12] If SortedList has exactly the same public interface as List, is SortedList a kind-of List?
  (strengthened the wording in a few places)
• [23.5] When my base class's constructor calls a virtual function on its this object, why doesn't my derived class's override of that virtual function get invoked?
  (rewrote completely and added an example program)
• [23.8] Should a derived class redefine ("override") a member function that is non-virtual in a base class?
  (reworded the question — clarification)
• [23.9] What's the meaning of, Warning: Derived::f(char) hides Base::f(double)?
  (changed typo f(double) to f(float) thanks to Tarjei Knapstad)
• [26.9] When initializing static data members of built-in / intrinsic / primitive types, should I worry about the "static initialization order fiasco"?
  (reworded thanks to Orjan Petersson)
• [29.2] Where do I start? Why do I feel so confused, so stupid?
  (added sites for "sample problems")
• [29.16] Why is floating point so inaccurate? Why doesn't this print 0.43?
  (moved from the Miscellaneous Technical Issues section)
• [29.17] Why doesn't my floating-point comparison work?
  (added links to David Goldberg's paper and to Doug Priest's supplement thanks to Kevin Quitt; added a definition for isEqual(double,double) thanks to Steve Summit; moved from the Miscellaneous Technical Issues section)
• [32.5] How can I call a non-system C function f(int,char,float) from my C++ code?
  (changed "C code" to "C++ code" in the first sentence thanks to Sreenivas Sunil Penumarthy)
• [33.5] How can I avoid syntax errors when creating pointers to members?
  (made it clearer there is an and between the recommended typedef and macro)
• [33.6] How can I avoid syntax errors when calling a member function using a pointer-to-member-function?
  (made it clearer there is an and between the recommended typedef and macro)
• [33.7] How do I create and use an array of pointer-to-member-function?
  (made it clearer there is an and between the recommended typedef and macro)
• [37.4] Where can I get help on how to use STL?
  (wordsmithed for clarity)
• [37.9] Where can I get tons and tons of more information on C++ class libraries?
  (added the "with frames" URL for the C++ Libraries FAQ and the comment about google, both thanks to Henrik Haraldsson)
• [40.1] How can I generate HTML documentation for my classes? Does C++ have anything similar to javadoc?
  (moved from the Miscellaneous Technical Issues section)

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Big-picture changes:

• Added a new section on Newbie Questions / Answers.

20 New FAQs:

• [4.33] What updates were made for the 06/02 release?
• [6.15] What does the FAQ mean by "such and such is evil"?
• [21.12] If SortedList has exactly the same public interface as List, is SortedList a kind-of List?
  (thanks to a conversation with Dave Mikesell)
• [26.12] How can I tell if an integer is a power of two without looping?
  (thanks to S.K. Mody)
• [29.1] What is this "newbie section" all about?
• [29.2] Where do I start? Why do I feel so confused, so stupid?
  (thanks to a question from John Lester)
• [29.5] What are the criteria for choosing between short / int / long data types?
  (thanks to a question from John Lester)
• [29.6] What the heck is a const variable? Isn't that a contradiction in terms?
  (thanks to a question from John Lester)
• [29.7] Why would I use a const variable / const identifier as opposed to #define?
  (thanks to a question from John Lester)
• [29.8] Are you saying that the preprocessor is evil?
• [29.9] What is the "standard library"? What is included / excluded from it?
  (thanks to a question from John Lester)
• [29.10] How should I lay out my code? When should I use spaces, tabs, and/or newlines in my code?
  (thanks to a question from John Lester)
• [29.11] Is it okay if a lot of numbers appear in my code?
• [29.12] What's the point of the L, U and f suffixes on numeric literals?
  (thanks to a question from John Lester)
• [29.13] I can understand the and (&&) and or (||) operators, but what's the purpose of the not (!) operator?
  (thanks to a question from John Lester)
• [29.14] Is !(a < b) logically the same as a >= b?
• [29.15] What is this NaN thing?
• [29.19] What is the type of an enumeration such as enum Color? Is it of type int?
  (thanks to a question from John Lester)
• [29.20] If an enumeration type is distinct from any other type, what good is it? What can you do with it?
  (thanks to a question from John Lester)
• [38.6] What's the difference between C++ and Visual C++?
  (based on a question from Lavanya Mahashankar)

13 Changed FAQs:

• [2.12] Where can I find the C++ FAQ translated into Portuguese?
  (updated the URL)
• [3.1] Is there a C++ FAQ Book in addition to this on-line C++ FAQ?
  (changed the URL for the book cover and excerpts thanks to Thomas Hansen; also added the sample chapter and source code.)
• [5.6] Wait a minute, does that previous FAQ say to not answer their question just because it's already answered in the FAQ?!?
  (fixed misspelling in "cripple" thanks to John Marshall plus general rewording)
• [5.13] What about spam?
  (fixed a typo thanks to Paul Savage)
• [10.6] Should my constructors use "initialization lists" or "assignment"?
  (added symmetry argument wrt non-static const members thanks to Tanmoy Bhattacharya)
• [10.16] Why doesn't the construct-on-first-use idiom use a static object instead of a static pointer?
  (made substantive changes to the second-to-last paragraph thanks to Amitha Perera and Wil Evers)
• [18.13] What do I do if I want a const member function to make an "invisible" change to a data member?
  (reworded the question to distinguish "invisible change" from "invisible data member" thanks to Thomas Hansen)
• [26.4] But, but, but what about machines where a char has more than 8 bits? Surely you're not saying a C++ byte might have more than 8 bits, are you?!?
  (removed a superfluous statement)
• [26.6] I'm sooooo confused. Would you please go over the rules about bytes, chars, and characters one more time?
  (rewrote; changed the example from the mythical FOO machine to a PDP-10, plus added words showing how to simulate pointers using software, much thanks to Andrew Koenig)
• [26.7] What is a "POD type"?
  (added note that POD types can contain non-virtual member functions thanks to Andrew Koenig)
• [26.8] When initializing non-static data members of built-in / intrinsic / primitive types, should I use the "initialization list" or assignment?
  (clarified the cross-reference)
• [26.9] When initializing static data members of built-in / intrinsic / primitive types, should I worry about the "static initialization order fiasco"?
  (made it clearer that the FAQ provides a solution)
• [38.5] Where can I get information about the C++ compiler from {Borland, IBM, Microsoft, Sun, etc.}?
  (updated the link to KAI C++)

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Big-picture changes:

• Added a new section on built-in / intrinsic / primitive data types.
• Updated the link to the Portuguese translation.

16 New FAQs:

• [4.34] What updates were made for the 05/02 release?
• [5.6] Wait a minute, does that previous FAQ say to not answer their question just because it's already answered in the FAQ?!?
• [15.17] How can I tell {if a key, which key} was pressed before the user presses the ENTER key?
  (inspired by a posting by Alan Didey)
• [15.18] How can I make it so keys pressed by users are not echoed on the screen?
• [15.19] How can I move the cursor around on the screen?
• [26.1] Can sizeof(char) be 2 on some machines? For example, what about double-byte characters?
  (inspired by Randy Sherman)
• [26.2] What are the units of sizeof?
  (inspired by Randy Sherman)
• [26.3] Whoa, but what about machines or compilers that support multibyte characters. Are you saying that a "character" and a char might be different?!?
  (inspired by Randy Sherman)
• [26.4] But, but, but what about machines where a char has more than 8 bits? Surely you're not saying a C++ byte might have more than 8 bits, are you?!?
  (thanks to Randy Sherman)
• [26.5] Okay, I could imagine a machine with 9-bit bytes. But surely not 16-bit bytes or 32-bit bytes, right?
  (thanks to Randy Sherman)
• [26.6] I'm sooooo confused. Would you please go over the rules about bytes, chars, and characters one more time?
  (thanks to Randy Sherman)
• [26.7] What is a "POD type"?
• [26.8] When initializing non-static data members of built-in / intrinsic / primitive types, should I use the "initialization list" or assignment?
• [26.9] When initializing static data members of built-in / intrinsic / primitive types, should I worry about the "static initialization order fiasco"?
• [26.10] Can I define an operator overload that works with built-in / intrinsic / primitive types?
• [26.11] When I delete an array of some built-in / intrinsic / primitive type, why can't I just say delete a instead of delete[] a?

5 Changed FAQs:

• [6.14] What are some "interview questions" I could ask that would let me know if candidates really know their stuff?
  (rewrote from scratch thanks to Robin)
• [7.6] How can I prevent other programmers from violating encapsulation by seeing the private parts of my class?
  (minor rewording)
• [11.14] Is there a way to force new to allocate memory from a specific memory area?
  (two typos ("myPool" vs. "pool") in the code were fixed thanks to Randy Sherman)
• [32.3] How can I include a non-system C header file in my C++ code?
  (fixed a grammatical error in the first paragraph thanks to Randy Sherman)
• [38.13] Is it possible to convert C++ to C?
  (added a URL for Cfront and reworded the third bullet thanks to Richard T. Guy)

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3 New FAQs:

• [4.35] What updates were made for the 04/02 release?
• [11.14] Is there a way to force new to allocate memory from a specific memory area?
  (inspired by a conversation with Tuan Tran)
• [27.14] Should I use "unusual" syntax?

4 Changed FAQs:

• [2.1] Where's the closest mirror site to access this document?
  (added URL to the mirror site in the Netherlands thanks to Almer Visser)
• [13.13] Should I design my classes from the outside (interfaces first) or from the inside (data first)?
  (rewrote the rationale for hiding nodes as inspired by a discussion with Michael Lacher)
• [27.13] Are there any other sources of coding standards?
  (added several new links and updated numerous changed URLs thanks to John Vorwald)
• [38.5] Where can I get information about the C++ compiler from {Borland, IBM, Microsoft, Sun, etc.}?
  (updated URLs for Intel's and Watcom's C++ compilers, and added Open Watcom, thanks to Dave Symonds)

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Global changes:

• Changed the HTML "anchor" scheme so it conforms to the standard. Thanks to Eric Anderson for pointing this out.

4 New FAQs:

• [4.36] What updates were made for the 03/02 release?
• [6.14] What are some "interview questions" I could ask that would let me know if candidates really know their stuff?
  (thanks to inspiration from Shawn Panosian)
• [35.12] Why can't I separate the definition of my templates class from its declaration and put it inside a .cpp file?
  (thanks to Assaf Lavie)
• [40.1] How can I generate HTML documentation for my classes? Does C++ have anything similar to javadoc?
  (thanks to Joe Linoff)

27 Changed FAQs:

• [3.1] Is there a C++ FAQ Book in addition to this on-line C++ FAQ?
  (changed the URL for book excerpts thanks to Chris Young)
• [5.1] What does IMHO mean? (or IMO, IMNSHO, FWIW, OTOH, etc.)?
  (added OO)
• [6.11] Is C++ backward compatible with ANSI/ISO C?
  (clarified the relationship between f() in C and f(...) in C++ thanks to Stefan Farfeleder)
• [6.13] Where can I get a copy of the ANSI/ISO C++ standard?
  (swapped some mixed up links thanks to Randal Leistikow)
• [8.8] What is a handle to an object? Is it a pointer? Is it a reference? Is it a pointer-to-a-pointer? What is it?
  (changed pointers-to-references into references-to-pointers thanks to Scott Douglass)
• [13.1] What's the deal with operator overloading?
  (added comment about templates and intrinsic types thanks to Phil Hibbs)
• [15.1] Why should I use <iostream> instead of the traditional <cstdio>?
  (corrected grammar of first bullet ("better type safety" ==> "more type-safe") thanks to Tristan Miller)
• [15.16] Why can't I open a file in a different directory such as "..\test.dat"?
  (added an explanation as to why "/" is better than "\\" thanks to Chris Young)
• [16.3] Can I free() pointers allocated with new? Can I delete pointers allocated with malloc()?
  (strengthened)
• [18.13] What do I do if I want a const member function to make an "invisible" change to a data member?
  (added a caveat about this being a Set const* const thanks to Steve White)
• [20.6] I have a heterogeneous list of objects, and my code needs to do class-specific things to the objects. Seems like this ought to use dynamic binding but can't figure it out. What should I do?
  (fixed typo in a typedef thanks to Salminen Kari; plus various clarifications throughout)
• [20.8] What is a "virtual constructor"?
  (added parenthetical recommendation about slicing thanks to Jesse Jones)
• [21.2] Converting Derived* → Base* works OK; why doesn't Derived** → Base** work?
  (added a paragraph near the end about using a pointer cast thanks to Steve White)
• [21.6] Is a Circle a kind-of an Ellipse?
  (reworded)
• [21.7] Are there other options to the "Circle is/isnot kind-of Ellipse" dilemma?
  (added words allowing Circle to be a state of Ellipse rather than a class in itself thanks to Nicholas Leippe)
• [21.8] But I have a Ph.D. in Mathematics, and I'm sure a Circle is a kind of an Ellipse! Does this mean Marshall Cline is stupid? Or that C++ is stupid? Or that OO is stupid?
  (softened things up in two spots (thanks to Salminen Kari and Nicholas Leippe) and made it even more in-your-face in other spots (blame the author for this second set of changes — I'm the meanie))
• [27.8] What source-file-name convention is best? foo.cpp? foo.C? foo.cc?
  (rewrote/wordsmithed thanks to Michael Tiller)
• [27.13] Are there any other sources of coding standards?
  (removed a dead link thanks to Phil Hibbs)
• [28.7] What are some best-of-breed C++ programming-by-example guides?
  (added Musser's STL book thanks to Xavier Outhier from D2SET scientific and technology non profit association)
• [29.17] Why doesn't my floating-point comparison work?
  (added new book references thanks to Alan McKenney)
• [37.2] Where can I get a copy of "STL"?
  (removed dead link to Musser's STL site thanks to Xavier Outhier from D2SET scientific and technology non profit association)
• [37.4] Where can I get help on how to use STL?
  (removed dead link to Musser's STL site thanks to Xavier Outhier from D2SET scientific and technology non profit association; added link to book section)
• [37.9] Where can I get tons and tons of more information on C++ class libraries?
  (added the URL to www.mathtools.net/C_C__/ thanks to Ophir Herbst; also added the boost.org URL)
• [38.1] Where can I download a free C++ compiler?
  (added Digital Mars to the list (thanks Walter!))
• [38.4] How can I decompile an executable program back into C++ source code?
  (added caveat at the end re legitimate reasons to decompile)
• [38.5] Where can I get information about the C++ compiler from {Borland, IBM, Microsoft, Sun, etc.}?
  (removed Symantec C++ since Symantec's web site says it is "discontinued," thanks to Richard Gill; added an annotation that the Digital Mars compiler is free, thanks to Walter Bright; and added the URL to the Cygwin-compiled version of GCC, thanks to Wouter Demuynck)
• [40.3] Are there any pretty-printers that reformat C++ source code?
  (added "Source Styler for C++" thanks to Alison Boyce)

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New features:

• You can now search the C++ FAQ (thanks to www.google.com).
• The FAQ has now been translated into Chinese using the GB encoding (typically used on the Chinese mainland).

13 New FAQs:

• [4.37] What updates were made for the 08/01 release?
• [5.10] Should I post job advertisements and/or resumés on comp.lang.c++?
  (thanks to David Harmon and Brian B. Rodenborn)
• [5.11] What if I really need a job; should I post my resumé on comp.lang.c++?
  (thanks to David Harmon and Brian B. Rodenborn)
• [5.12] What should I do to someone who posts something off-topic?
• [5.13] What about spam?
• [10.16] Why doesn't the construct-on-first-use idiom use a static object instead of a static pointer?
• [10.18] Do I need to worry about the "static initialization order fiasco" for variables of built-in/intrinsic types?
  (thanks to Cyril Schmidt)
• [20.6] I have a heterogeneous list of objects, and my code needs to do class-specific things to the objects. Seems like this ought to use dynamic binding but can't figure it out. What should I do?
  (based on an email discussion with Jeramie Hicks)
• [23.11] How can I set up my class so it won't be inherited from?
• [23.12] How can I set up my member function so it won't be overridden in a derived class?
• [27.11] Why do people worry so much about pointer casts and/or reference casts?
• [29.17] Why doesn't my floating-point comparison work?
  (thanks to Stan Brown)
• [38.13] Is it possible to convert C++ to C?
  (thanks to J. Stephen Adamczyk and Greg Comeau)

24 Changed FAQs:

• [2.1] Where's the closest mirror site to access this document?
  (removed the Finland mirror site — it wasn't being kept up-to-date)
• [2.6] Where can I find the C++ FAQ translated into Chinese?
  (added the URL for the GB-encoded version thanks to Shen Min for the translation)
• [10.6] Should my constructors use "initialization lists" or "assignment"?
  (reworded various things thanks to Stan Brown)
• [10.7] Should you use the this pointer in the constructor?
  (wordsmithed thanks to Stan Brown)
• [10.14] What's the "static initialization order fiasco"?
  (closed loophole wrt built-in/intrinsic types thanks to Cyril Schmidt)
• [10.15] How do I prevent the "static initialization order fiasco"?
  (closed loophole wrt built-in/intrinsic types thanks to Cyril Schmidt)
• [10.17] How do I prevent the "static initialization order fiasco" for my static data members?
  (closed loophole wrt built-in/intrinsic types thanks to Cyril Schmidt)
• [10.20] What is the "Named Parameter Idiom"?
  (wordsmithed and added last paragraph with inspiration from Stan Brown)
• [14.2] Do friends violate encapsulation?
  (added the last paragraph with inspiration from Stan Brown)
• [14.4] What does it mean that "friendship isn't inherited, transitive, or reciprocal"?
  (wordsmithed ("nor" vs. "or") thanks to Herbert Gintis)
• [16.6] Do I need to check for NULL after p = new Fred()?
  (changed endl to std::endl)
• [16.25] Can you absolutely prevent people from subverting the reference counting mechanism, and if so, should you?
  (wordsmithed thanks to Stan Brown)
• [16.26] Can I use a garbage collector in C++?
  (added cross-references thanks to Stan Brown)
• [16.27] What are the two kinds of garbage collectors for C++?
  (added a URL for Attardi and Flagella's CMM thanks to Markus Laker)
• [19.7] How can I protect derived classes from breaking when I change the internal parts of the base class?
  (wordsmithed thanks to Stan Brown)
• [20.8] What is a "virtual constructor"?
  (added the paragraph about MS VC++ 6.0's mishandling of Covariant Return Types; thanks to Karthik for pointing this out)
• [28.4] Should I buy one book, or several?
  (wordsmithed thanks to Stan Brown)
• [32.1] What do I need to know when mixing C and C++ code?
  (fixed a typo thanks to Kumaran Surrendra; added the paragraph on compiling everything, even C-style code, using a C++ compiler thanks to Gary Jenkins)
• [37.2] Where can I get a copy of "STL"?
  (added comment about "<string>" thanks to Stan Brown)
• [38.5] Where can I get information about the C++ compiler from {Borland, IBM, Microsoft, Sun, etc.}?
  (added URL for Digital Mars C++ thanks to Walter Bright)
• [39.1] How do I convert a value (a number, for example) to a std::string?
  (changed <stdio> to <cstdio> thanks to Stan Brown)
• [39.2] How do I convert a std::string to a number?
  (changed <stdio> to <cstdio> thanks to Stan Brown)
• [39.6] What should be done with macros that need to paste two tokens together?
  (removed ambivalence regarding second layer of indirection when using ## thanks to Joshua Fraser and Ronald Fischer)
• [40.2] Is there a TeX or LaTeX macro that fixes the spacing on "C++"?
  (wordsmithed thanks to Stan Brown)

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Global changes:

• Updated the opening page so it lists both the chain of recent changes as well as the table of recent changes. This improvement is thanks to a suggestion by John Kewley.
• Moved the main FAQ site to www.parashift.com/c++-faq/. (This was unfortunately necessary due to a business issue involving AT&T and the previous web hosting company, Cerf-Net.)

11 New FAQs:

• [2.13] Where can I find the C++ FAQ translated into Russian?
  (thanks to Yaroslav Mironov)
• [4.38] What updates were made for the 04/01 release?
• [8.4] What does object.method1().method2() mean?
  (thanks to Robert Cullen)
• [8.8] What is a handle to an object? Is it a pointer? Is it a reference? Is it a pointer-to-a-pointer? What is it?
• [10.20] What is the "Named Parameter Idiom"?
• [16.19] What's another way to build a Matrix template?
  (thanks to an idea from Jesper Rasmussen)
• [16.25] Can you absolutely prevent people from subverting the reference counting mechanism, and if so, should you?
• [23.1] Is it okay for a non-virtual function of the base class to call a virtual function?
• [23.2] That last FAQ confuses me. Is it a different strategy from the other ways to use virtual functions? What's going on?
• [28.7] What are some best-of-breed C++ programming-by-example guides?
• [35.4] How do I explicitly select which version of a function template should get called?
  (with help from Perry Rapp)

27 Changed FAQs:

• [5.2] How do I get other people to do my homework problem for me?
  (added stuff about the evils of asking others to do your homework for you via email)
• [6.13] Where can I get a copy of the ANSI/ISO C++ standard?
  (total rewrite; changed several URLs thanks to Brian K. Hamon and Garen Parham)
• [9.3] Do inline functions improve performance?
  (explained "code bloat" and also added lots of if's, and's and but's)
• [10.6] Should my constructors use "initialization lists" or "assignment"?
  (rewrote)
• [10.7] Should you use the this pointer in the constructor?
  (rewrote because of a suggestion from Perry Rapp)
• [10.11] Why can't I initialize my static member data in my constructor's initialization list?
  (added a "," in the initialization list thanks to Yaroslav Mironov)
• [14.2] Do friends violate encapsulation?
  (made a bit more emphatic)
• [14.4] What does it mean that "friendship isn't inherited, transitive, or reciprocal"?
  (added the "not reciprocal" item thanks to Karel Roose)
• [15.9] But shouldn't I always use a printOn() method rather than a friend function?
  (fixed a bug thanks to Richard Hector)
• [16.17] But the previous FAQ's code is SOOOO tricky and error prone! Isn't there a simpler way?
  (fixed the Star Trek movie number thanks to Chris Sheppard, wordsmithed last paragraph at the suggestion of Perry Rapp)
• [16.22] How do I do simple reference counting?
  (moved definition of Fred::create() methods below the definition of class FredPtr)
• [16.27] What are the two kinds of garbage collectors for C++?
  (added a URL for Bartlett's collector thanks to Abhishek)
• [17.8] How can I handle a constructor that fails?
  (fixed typo ("its" vs. "it's") thanks to Wes Bemont)
• [24.2] How are "private inheritance" and "composition" similar?
  (changed the syntax to using Engine::start; and added the sixth distinction thanks to Stan Brown; added the third similarity; added "aggregation" as another synonym; wordsmithed various parts)
• [27.1] What are some good C++ coding standards?
  (fixed typo changing "where" to "were" thanks to Robert Marshall)
• [27.12] Which is better: identifier names that_look_like_this or identifier names thatLookLikeThis?
  (clarified the last paragraph)
• [27.13] Are there any other sources of coding standards?
  (added a new URL thanks to Christopher Lott; added www.arcticlabs.com/codingstandards/ thanks to Richard)
• [28.4] Should I buy one book, or several?
  (rewrote; added the "programming by example" category)
• [31.2] What is "virtual data," and how-can / why-would I use it in C++?
  (fixed the sentence just before Pros & Cons list (changed StretchableArray to StretchableStack) thanks to Harri Klapuri)
• [32.2] How can I include a standard C header file in my C++ code?
  (added the whole section on "compiling C code with a C++ compiler," with inspiration thanks to Sebastian Kapfer)
• [33.7] How do I create and use an array of pointer-to-member-function?
  (removed the array size from the declaration of array a, that way there's one less thing to change if someone ever adds another function-pointer to the array thanks to Serge Ansay)
• [34.1] Why should I use container classes rather than simple arrays?
  (clarified "local" vs. "non-static local" thanks to Garen Parham)
• [38.1] Where can I download a free C++ compiler?
  (changed to a different site since the old URL was dead thanks to Victor R. Volkman)
• [38.5] Where can I get information about the C++ compiler from {Borland, IBM, Microsoft, Sun, etc.}?
  (fixed "Semantic" to "Symantec" and "Gary Comeau" to "Greg Comeau" thanks to Scott Tringali; fixed the URL to SGI's compiler thanks to Toon Knapen)
• [38.11] Is there a yacc-able C++ grammar?
  (rewrote; added a new grammar/lexer plus a new URL for the old grammar/lexer thanks to Ed Willink)
• [40.2] Is there a TeX or LaTeX macro that fixes the spacing on "C++"?
  (added a new LaTeX macro thanks to Bob Kline; rewrote)
• [40.3] Are there any pretty-printers that reformat C++ source code?
  (fixed the URL for Artistic Style thanks to Claus Dahl; added A2PS thanks to Clark Dorman)

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Global changes:

• Moved the main FAQ site to www.parashift.com/c++-faq/. (This was unfortunately necessary due to a business issue involving AT&T and the previous web hosting company, Cerf-Net.)

12 New FAQs:

• [4.39] What updates were made for the 07/00 release?
• [11.13] Should my destructor throw an exception when it detects a problem?
• [15.9] But shouldn't I always use a printOn() method rather than a friend function?
• [16.26] Can I use a garbage collector in C++?
  (thanks to Hans Boehm)
• [16.27] What are the two kinds of garbage collectors for C++?
  (thanks to Hans Boehm)
• [16.28] Where can I get more info on garbage collectors for C++?
• [17.1] What are some ways try / catch / throw can improve software quality?
• [17.9] How can I handle a destructor that fails?
• [21.9] Perhaps Ellipse should inherit from Circle then?
• [34.1] Why should I use container classes rather than simple arrays?
  (with help from Stan Brown)
• [39.1] How do I convert a value (a number, for example) to a std::string?
  (thanks to Rob Stewart)
• [39.2] How do I convert a std::string to a number?
  (thanks to Rob Stewart)

72 Changed FAQs:

• [2.6] Where can I find the C++ FAQ translated into Chinese?
  (updated the URL)
• [3.1] Is there a C++ FAQ Book in addition to this on-line C++ FAQ?
  (added BookPool.com and AllDirect.com thanks to Stan Brown, plus reorganized)
• [3.2] Is there a big difference between this on-line C++ FAQ and the C++ FAQ Book?
  (changed 'much' to 'many' thanks to Stan Brown)
• [6.6] Who uses C++?
  (rewrote)
• [6.9] Are virtual functions (dynamic binding) central to OO/C++?
  (inserted "the" before "difference" thanks to Stan Brown and reworded references to STL)
• [6.12] Is C++ standardized?
  (changed "has been finalized" to "was finalized" thanks to Stan Brown)
• [6.13] Where can I get a copy of the ANSI/ISO C++ standard?
  (added URLs to free copies of CD2)
• [9.5] Why should I use inline functions instead of plain old #define macros?
  (rewrote the sentence on #define being evil)
• [10.5] Which constructor gets called when I create an array of Fred objects?
  (changed so it uses new-style headers and the std:: syntax and reworded references to STL)
• [10.8] What is the "Named Constructor Idiom"?
  (fixed a typo (Fred vs. Point) in the prose thanks to Roy LeCates)
• [12.3] OK, OK, already; I'll handle self-assignment. How do I do it?
  (reworded the last paragraph)
• [13.3] What are some examples of operator overloading?
  (changed so it uses the std:: syntax)
• [13.6] Can I overload operator== so it lets me compare two char[] using a string comparison?
  (changed so it uses the std:: syntax)
• [13.10] How do I create a subscript operator for a Matrix class?
  (changed so it uses new-style headers and the std:: syntax)
• [13.13] Should I design my classes from the outside (interfaces first) or from the inside (data first)?
  (changed so it uses new-style headers and the std:: syntax and reworded references to STL)
• [15.1] Why should I use <iostream> instead of the traditional <cstdio>?
  (renamed "subclassable" to "inheritable" and revamped to use new-style headers)
• [15.2] Why does my program go into an infinite loop when someone enters an invalid input character?
  (changed so it uses new-style headers and the std:: syntax)
• [15.4] How does that funky while (std::cin >> foo) syntax work?
  (changed so it uses new-style headers and the std:: syntax)
• [15.5] Why does my input seem to process past the end of file?
  (changed so it uses new-style headers and the std:: syntax)
• [15.6] Why is my program ignoring my input request after the first iteration?
  (changed so it uses new-style headers and the std:: syntax)
• [15.8] How can I provide printing for my class Fred?
  (changed so it uses new-style headers and the std:: syntax)
• [15.10] How can I provide input for my class Fred?
  (changed so it uses new-style headers and the std:: syntax)
• [15.11] How can I provide printing for an entire hierarchy of classes?
  (changed so it uses new-style headers and the std:: syntax)
• [15.13] How can I "reopen" std::cin and std::cout in binary mode?
  (changed so it uses new-style headers and the std:: syntax)
• [15.16] Why can't I open a file in a different directory such as "..\test.dat"?
  (changed so it uses new-style headers and uses the std:: syntax)
• [16.6] Do I need to check for NULL after p = new Fred()?
  (changed so it uses new-style headers and the std:: syntax)
• [16.7] How can I convince my (older) compiler to automatically check new to see if it returns NULL?
  (changed the example to use throw rather than abort() thanks to Stan Brown; changed to use new-style headers and the std:: syntax)
• [16.14] After p = new Fred[n], how does the compiler know there are n objects to be destructed during delete[] p?
  (changed "popluar" to "popular" thanks to Fabrice Clerc)
• [16.16] How do I allocate multidimensional arrays using new?
  (fixed a leak in the third manipulateArray() by moving another for loop into the try block)
• [16.17] But the previous FAQ's code is SOOOO tricky and error prone! Isn't there a simpler way?
  (clarified the last paragraph)
• [16.18] But the above Matrix class is specific to Fred! Isn't there a way to make it generic?
  (rewrote)
• [16.20] Does C++ have arrays whose length can be specified at run-time?
  (changed so it uses new-style headers and the std:: syntax and reworded references to STL)
• [16.23] How do I provide reference counting with copy-on-write semantics?
  (rewrote the first paragraph for clarity thanks to Fabrice Clerc)
• [16.24] How do I provide reference counting with copy-on-write semantics for a hierarchy of classes?
  (changed so it uses new-style headers and the std:: syntax)
• [17.11] How do I change the string-length of an array of char to prevent memory leaks even if/when someone throws an exception?
  (rewrote the last half)
• [18.1] What is "const correctness"?
  (changed so it uses new-style headers and the std:: syntax)
• [18.2] How is "const correctness" related to ordinary type safety?
  (changed so it uses new-style headers and the std:: syntax)
• [18.10] What is a "const member function"?
  (removed a spurious ")" thanks to Stan Brown)
• [18.15] Why does the compiler allow me to change an int after I've pointed at it with a int const*?
  (changed so it uses new-style headers and the std:: syntax)
• [19.3] How do you express inheritance in C++?
  (added "derived class of" to the list of synonyms)
• [19.7] How can I protect derived classes from breaking when I change the internal parts of the base class?
  (renamed "subclass" to "derived class")
• [21.4] Is an array of Derived a kind-of array of Base?
  (changed so it uses new-style headers and the std:: syntax and reworded references to STL)
• [21.5] Does array-of-Derived is-not-a-kind-of array-of-Base mean arrays are bad?
  (changed so it uses new-style headers and the std:: syntax and reworded references to STL)
• [22.3] What is an ABC?
  (renamed "subclass" to "derived class")
• [22.4] What is a "pure virtual" member function?
  (renamed "subclass" to "derived class")
• [24.3] Which should I prefer: composition or private inheritance?
  (changed so it uses new-style headers and the std:: syntax)
• [24.5] How is protected inheritance related to private inheritance?
  (renamed "subclass" to "derived class")
• [24.6] What are the access rules with private and protected inheritance?
  (renamed "subclass" to "derived class")
• [27.4] What's the difference between <xxx> and <xxx.h> headers?
  (changed <xyz.h> to <xxx.h> and wordsmithed thanks to Stan Brown)
• [27.6] Is the ?: operator evil since it can be used to create unreadable code?
  (changed so it uses new-style headers and the std:: syntax)
• [27.10] Are there any lint-like guidelines for C++?
  (changed so it uses new-style headers and the std:: syntax)
• [27.12] Which is better: identifier names that_look_like_this or identifier names thatLookLikeThis?
  (improved the precision and added the last two paragraphs thanks to Chris Hurst)
• [27.13] Are there any other sources of coding standards?
  (fixed some URLs thanks to James S. Adelman and Stan Brown)
• [29.16] Why is floating point so inaccurate? Why doesn't this print 0.43?
  (changed so it uses new-style headers and the std:: syntax)
• [30.4] How do you use inheritance in C++, and is that different from Smalltalk?
  (renamed "subclass" to "derived class")
• [30.5] What are the practical consequences of differences in Smalltalk/C++ inheritance?
  (renamed "subclass" to "derived class")
• [31.3] What's the difference between virtual data and dynamic data?
  (renamed "subclass" to "derived class")
• [31.8] Does the poor performance of reference semantics mean I should pass-by-value?
  (renamed "subclass" to "derived class")
• [34.2] How can I make a perl-like associative array in C++?
  (changed so it uses new-style headers and the std:: syntax)
• [34.5] How can I insert/access/change elements from a linked list/hashtable/etc?
  (reworded, plus changed so it uses new-style headers and the std:: syntax)
• [35.2] What's the syntax / semantics for a "class template"?
  (changed so it uses new-style headers and the std:: syntax)
• [35.3] What's the syntax / semantics for a "function template"?
  (changed so it uses new-style headers and the std:: syntax)
• [37.1] What is the "STL"?
  (changed so it uses new-style headers and the std:: syntax)
• [37.2] Where can I get a copy of "STL"?
  (added URLs for the SGI implementation and STLport thanks to Stan Brown)
• [37.3] How can I find a Fred object in an STL container of Fred* such as std::vector<Fred*>?
  (changed so it uses new-style headers and the std:: syntax)
• [38.5] Where can I get information about the C++ compiler from {Borland, IBM, Microsoft, Sun, etc.}?
  (updated the URL for IBM VisualAge C++ thanks to Rick Alther; updated the URL for GNU C++ thanks to Martin Honnen)
• [39.4] What should be done with macros that contain if?
  (added the last three paragraphs, including the link showing why we don't use do {...} while (false))
• [39.5] What should be done with macros that have multiple lines?
  (changed "if (1)..." to "if (true)..." and "do...while (0)" to "do...while (false)")
• [39.8] What are the C++ scoping rules for for loops?
  (because the scoping rules for for loops are no longer "new" (thanks Stan Brown), rewote the FAQ)
• [39.14] Why can't I put a forward-declared class in a std::vector<>?
  (changed so it uses new-style headers and the std:: syntax)
• [40.3] Are there any pretty-printers that reformat C++ source code?
  (added HPS Beauty)
• [40.6] Why does my DOS C++ program says "Sorry: floating point code not linked"?
  (added a cross reference and updated to new header syntax)

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4 New FAQs:

• [4.40] What updates were made for the 03/00 release?
• [39.4] What should be done with macros that contain if?
• [39.5] What should be done with macros that have multiple lines?
• [39.6] What should be done with macros that need to paste two tokens together?

15 Changed FAQs:

• [2.12] Where can I find the C++ FAQ translated into Portuguese?
  (updated the URL for the Portuguese translation of the FAQ thanks to Ricardo F. de Oliveira)
• [3.1] Is there a C++ FAQ Book in addition to this on-line C++ FAQ?
  (rewrote)
• [3.2] Is there a big difference between this on-line C++ FAQ and the C++ FAQ Book?
  (rewrote)
• [6.13] Where can I get a copy of the ANSI/ISO C++ standard?
  (changed the URL for the electronic copy of the Standard thanks to Wolfgang Haefelinger)
• [9.5] Why should I use inline functions instead of plain old #define macros?
  (added cross references to other evilness of macros)
• [11.8] What if I can't wrap the local in an artificial block?
  (added the note about constructors at the end)
• [13.13] Should I design my classes from the outside (interfaces first) or from the inside (data first)?
  (added friend relationship between LinkedListIterator and LinkedList thanks to Monica Garcia Garcia; reworded "In the case of OO software..." sentence thanks to Fabrice Clerc)
• [18.13] What do I do if I want a const member function to make an "invisible" change to a data member?
  (added a warning against use of const_cast on const objects thanks to TiTi)
• [20.8] What is a "virtual constructor"?
  (added the paragraph on Covariant Return Types)
• [30.3] Which is a better fit for C++: "static typing" or "dynamic typing"?
  (added cross references to evilness of macros)
• [32.4] How can I modify my own C header files so it's easier to #include them in C++ code?
  (added the "macros are sometimes useful" paragraph at the end)
• [33.1] Is the type of "pointer-to-member-function" different from "pointer-to-function"?
  (changed another "It's" to "Its" thanks to Chris Young)
• [33.5] How can I avoid syntax errors when creating pointers to members?
  (added the "macros are sometimes useful" paragraph at the end)
• [33.6] How can I avoid syntax errors when calling a member function using a pointer-to-member-function?
  (added the "macros are sometimes useful" paragraph at the end)
• [33.7] How do I create and use an array of pointer-to-member-function?
  (added the "macros are sometimes useful" paragraph at the end)

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3 New FAQs:

• [4.41] What updates were made for the 01/00 release?
• [10.7] Should you use the this pointer in the constructor?
  (with the help of Jim Hyslop)
• [27.4] What's the difference between <xxx> and <xxx.h> headers?
  (thanks to Stan Brown)

16 Changed FAQs:

• [2.1] Where's the closest mirror site to access this document?
  (changed the rationale for choosing a close site thanks to Stan Brown)
• [5.1] What does IMHO mean? (or IMO, IMNSHO, FWIW, OTOH, etc.)?
  (added IMAO thanks to Charles R Martin)
• [5.14] How do I get the FAQs for a particular newsgroup?
  (added www.faqs.org thanks to Dan Kegel)
• [6.9] Are virtual functions (dynamic binding) central to OO/C++?
  (reworded the second paragraph thanks to Stan Brown)
• [6.12] Is C++ standardized?
  (changed "American National Standards Organization" to "American National Standards Institute" thanks to Mark Jones; also reworded first paragraph thanks to Stan Brown)
• [12.1] What is "self assignment"?
  (changed "knowning" to "knowing" thanks to Stan Brown)
• [12.3] OK, OK, already; I'll handle self-assignment. How do I do it?
  (reworded the last paragraph thanks to Stan Brown)
• [13.5] What operators can/cannot be overloaded?
  (got rid of #if/#else/#endif by splitting the example thanks to Stan Brown)
• [15.16] Why can't I open a file in a different directory such as "..\test.dat"?
  (added an explanation that the library routines treat "/" and "\" interchangeably thanks to Stan Brown)
• [18.16] Does "Fred const* p" mean that *p can't change?
  (added an indication that there might be other non-const ways to get at the object thanks to Stan Brown)
• [20.2] How can C++ achieve dynamic binding yet also static typing?
  (added the definition of polymorphism thanks to Kemberli Jennings)
• [22.5] How do you define a copy constructor or assignment operator for a class that contains a pointer to a (abstract) base class?
  (fixed Circle and Square so they inherit from Shape thanks to Paul Campbell)
• [33.1] Is the type of "pointer-to-member-function" different from "pointer-to-function"?
  (changed "It's type is..." to "Its type is..." thanks to Graham Borland)
• [34.5] How can I insert/access/change elements from a linked list/hashtable/etc?
  (reworded first 4 paragraphs thanks to Stan Brown)
• [38.2] Where can I get more information on using MFC and Visual C++?
  (updated the URL thanks to Katy Mulvey; changed the maintainer's name thanks to AllanW)
• [38.5] Where can I get information about the C++ compiler from {Borland, IBM, Microsoft, Sun, etc.}?
  (changed the URL for Watcom C++ thanks to Stephen Howe; added Comeau C++ thanks to Greg Comeau)

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8 New FAQs:

• [2.7] Where can I find the C++ FAQ translated into French?
  (with much thanks to translators S. Bailliez, L. Bize, F. Clerc, P. Elie and J. Lecomte)
• [4.42] What updates were made for the 10/99 release?
• [13.11] Why shouldn't my Matrix class's interface look like an array-of-array?
• [37.1] What is the "STL"?
• [39.11] How can I create two classes that both know about each other?
  (thanks to Steve Horne)
• [39.12] What special considerations are needed when forward declarations are used with member objects?
  (thanks to Steve Horne)
• [39.13] What special considerations are needed when forward declarations are used with inline functions?
  (thanks to Steve Horne)
• [39.14] Why can't I put a forward-declared class in a std::vector<>?
  (thanks to Steve Horne)

38 Changed FAQs:

• [6.12] Is C++ standardized?
  (changed "International Standards Organization" to "International Organization for Standardization" thanks to (NOSPAM)savvysoft2(AT)aol(DOT)com)
• [7.1] What is a class?
  (cleaned up wording so no one thinks int is a class thanks to Ron Natalie)
• [8.1] What is a reference?
  (added return type to main())
• [8.2] What happens if you assign to a reference?
  (inserted "state of the" to avoid ambiguity thanks to Donna)
• [8.3] What happens if you return a reference?
  (added return type to main())
• [10.5] Which constructor gets called when I create an array of Fred objects?
  (added return type to main(), plus added stuff about "explicit initialization of arrays" thanks to Keller Beyer)
• [10.8] What is the "Named Constructor Idiom"?
  (added return type to main())
• [12.1] What is "self assignment"?
  (added return type to main())
• [13.4] But operator overloading makes my class look ugly; isn't it supposed to make my code clearer?
  (added return type to main())
• [13.5] What operators can/cannot be overloaded?
  (added return type to main())
• [13.6] Can I overload operator== so it lets me compare two char[] using a string comparison?
  (replaced "class type" with "user-defined type" in first paragraph thanks to Daryle Walker)
• [13.10] How do I create a subscript operator for a Matrix class?
  (added return type to main(); added parameters to the instantiation of m in main() thanks to Boris Pulatov)
• [13.13] Should I design my classes from the outside (interfaces first) or from the inside (data first)?
  (added an admonition to not "roll your own" container classes)
• [15.2] Why does my program go into an infinite loop when someone enters an invalid input character?
  (added return type to main())
• [15.5] Why does my input seem to process past the end of file?
  (strengthened the message with another example)
• [15.8] How can I provide printing for my class Fred?
  (added return type to main())
• [15.10] How can I provide input for my class Fred?
  (added return type to main())
• [15.16] Why can't I open a file in a different directory such as "..\test.dat"?
  (added return type to main())
• [16.7] How can I convince my (older) compiler to automatically check new to see if it returns NULL?
  (added return type to main())
• [16.21] How can I force objects of my class to always be created via new rather than as locals or global/static objects?
  (added return type to main())
• [18.15] Why does the compiler allow me to change an int after I've pointed at it with a int const*?
  (added return type to main())
• [18.16] Does "Fred const* p" mean that *p can't change?
  (added return type to main())
• [21.2] Converting Derived* → Base* works OK; why doesn't Derived** → Base** work?
  (added return type to main(); added methods openGasCap() and fireNuclearMissle() — makes the example more exciting)
• [21.4] Is an array of Derived a kind-of array of Base?
  (added return type to main())
• [24.4] Should I pointer-cast from a private derived class to its base class?
  (changed PrivateDer to PrivatelyDer in last paragraph)
• [24.6] What are the access rules with private and protected inheritance?
  (rewritten with the using syntax; thanks to Stephen Vance)
• [29.16] Why is floating point so inaccurate? Why doesn't this print 0.43?
  (added return type to main())
• [32.2] How can I include a standard C header file in my C++ code?
  (added return type to main())
• [32.3] How can I include a non-system C header file in my C++ code?
  (added return type to main())
• [32.4] How can I modify my own C header files so it's easier to #include them in C++ code?
  (added return type to main())
• [32.5] How can I call a non-system C function f(int,char,float) from my C++ code?
  (added return type to main())
• [33.2] How do I pass a pointer-to-member-function to a signal handler, X event callback, system call that starts a thread/task, etc?
  (added return type to main())
• [34.2] How can I make a perl-like associative array in C++?
  (added return type to main())
• [35.2] What's the syntax / semantics for a "class template"?
  (added return type to main())
• [35.3] What's the syntax / semantics for a "function template"?
  (added return type to main())
• [38.1] Where can I download a free C++ compiler?
  (fixed the URL)
• [38.5] Where can I get information about the C++ compiler from {Borland, IBM, Microsoft, Sun, etc.}?
  (added Edison Design Group C++ thanks to Matt Page)
• [40.3] Are there any pretty-printers that reformat C++ source code?
  (added Artistic Style thanks to Philipp Berndt, fixed the URL for C++2LaTeX thanks to Vinay Kumar Nallamothu, fixed the URL for C-Clearly thanks to Bill Robertson; fixed the plaintext version (the "grind" definition didn't show up there) thanks to Nimrod Zimerman)

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2 New FAQs:

• [4.43] What updates were made for the 07/99 release?
• [38.1] Where can I download a free C++ compiler?

22 Changed FAQs:

• [1.6] On-line C++-FAQ != C++-FAQ-Book
  (updated due to the Second Edition of the book)
• [2.1] Where's the closest mirror site to access this document?
  (added Ireland mirror site: snet.wit.ie/GreenSpirit/c++-faq-lite)
• [2.2] What happened to the one-click-download option?
  (added "Windows 98" to last paragraph)
• [3.1] Is there a C++ FAQ Book in addition to this on-line C++ FAQ?
  (updated due to the Second Edition of the book)
• [6.6] Who uses C++?
  (corrected the growth rate)
• [6.9] Are virtual functions (dynamic binding) central to OO/C++?
  (added STL and generic programming)
• [6.13] Where can I get a copy of the ANSI/ISO C++ standard?
  (added new ways to get a copy via the web)
• [12.3] OK, OK, already; I'll handle self-assignment. How do I do it?
  (tightened the wording of the last paragraph thanks to Andy Glew)
• [15.4] How does that funky while (std::cin >> foo) syntax work?
  (corrected a serious bug: changed operator bool() to operator void*(); thanks to Rajinikanth Sivalingam)
• [16.24] How do I provide reference counting with copy-on-write semantics for a hierarchy of classes?
  (fixed a bug by making Fred a friend of Fred::Data)
• [18.10] What is a "const member function"?
  (changed "const pointer" to "pointer-to-const" thanks to Saieb Khalil)
• [20.7] When should my destructor be virtual?
  (changed "explicit destructor" to "explicitly defined destructor" to avoid confusion with the explicit keyword used with constructors)
• [23.8] Should a derived class redefine ("override") a member function that is non-virtual in a base class?
  (reworded first full paragraph)
• [27.13] Are there any other sources of coding standards?
  (removed the URL for the anti-guide (thanks to Bill Seymour for letting me know that the anti-guide disappeared))
• [28.5] What are some best-of-breed C++ morality guides?
  (updated info on C++ FAQs book because of its Second Edition)
• [28.6] What are some best-of-breed C++ legality guides?
  (fixed the ISBN for Bjarne Stroustrup's book)
• [31.1] What is value and/or reference semantics, and which is best in C++?
  (wordsmithed changes thanks to Lance Ware)
• [34.5] How can I insert/access/change elements from a linked list/hashtable/etc?
  (reworded item #3 thanks to John Millaway)
• [37.3] How can I find a Fred object in an STL container of Fred* such as std::vector<Fred*>?
  (fixed a typo in the code thanks to Scott Maxwell and Bill Sloan)
• [38.4] How can I decompile an executable program back into C++ source code?
  (wordsmithed changes thanks to Lance Ware)
• [38.5] Where can I get information about the C++ compiler from {Borland, IBM, Microsoft, Sun, etc.}?
  (corrected the URL for KAI C++ and added Rational APEX C/C++ thanks to Kevin Broadey; corrected the URL for Borland C++ FAQ thanks to Kent Reisdorph and Michael J. Reeves)
• [39.8] What are the C++ scoping rules for for loops?
  (wordsmithed thanks to Lance Ware)

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2 New FAQs:

• [4.44] What updates were made for the 06/98 release?
• [10.19] How can I handle a constructor that fails?

1 Changed FAQs:

• [37.9] Where can I get tons and tons of more information on C++ class libraries?
  (fixed the URL)

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Global changes:

• Removed the grey background color on the HTML version. It now displays in the Web Browser's own preferences.

5 New FAQs:

• [1.5] Trademarks
• [2.12] Where can I find the C++ FAQ translated into Portuguese?
• [4.45] What updates were made for the 05/98 release?
• [10.6] Should my constructors use "initialization lists" or "assignment"?
• [38.2] Where can I get more information on using MFC and Visual C++?

9 Changed FAQs:

• [2.2] What happened to the one-click-download option?
  (made it clearer why there is no FTP or HTTP address for downloading the FAQ)
• [6.12] Is C++ standardized?
  (rewrote now that the standard is here)
• [6.13] Where can I get a copy of the ANSI/ISO C++ standard?
  (rewrote now that the standard is here)
• [16.18] But the above Matrix class is specific to Fred! Isn't there a way to make it generic?
  (fixed Matrix's ctor thanks to Dhavide Aruliah)
• [16.23] How do I provide reference counting with copy-on-write semantics?
  (fixed Fred's default ctor thanks to Scott Harris)
• [37.3] How can I find a Fred object in an STL container of Fred* such as std::vector<Fred*>?
  (changed operator==() to operator()() thanks to Ali Tajeldin)
• [37.4] Where can I get help on how to use STL?
  (added the URL for the STL FAQ)
• [38.5] Where can I get information about the C++ compiler from {Borland, IBM, Microsoft, Sun, etc.}?
  (corrected the URL for Borland C++ & HP C++; added GNU C++, Intel Reference C++, KAI C++, and Portland Group C++)
• [40.3] Are there any pretty-printers that reformat C++ source code?
  (added a URL for "GNU indent")

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5 New FAQs:

• [4.46] What updates were made for the 09/97 release?
• [10.14] What's the "static initialization order fiasco"?
• [10.15] How do I prevent the "static initialization order fiasco"?
• [10.17] How do I prevent the "static initialization order fiasco" for my static data members?
• [16.18] But the above Matrix class is specific to Fred! Isn't there a way to make it generic?

8 Changed FAQs:

• [1.3] Copying Permissions
  (clarified)
• [5.1] What does IMHO mean? (or IMO, IMNSHO, FWIW, OTOH, etc.)?
  (added silly acronym-laden comment at the bottom (adapted from e-mail from Erik Corry)
• [16.17] But the previous FAQ's code is SOOOO tricky and error prone! Isn't there a simpler way?
  (fixed some inconsistencies between FredMatrix and Matrix thanks to Jeff Baker)
• [16.22] How do I do simple reference counting?
  (fixed FredPtr's constructor thanks to Chichiang Wan)
• [23.9] What's the meaning of, Warning: Derived::f(char) hides Base::f(double)?
  (rewritten with the using syntax; thanks to Matt Seitz)
• [38.5] Where can I get information about the C++ compiler from {Borland, IBM, Microsoft, Sun, etc.}?
  (corrected the URL for Symantec C++ thanks to Michel Joly de Lotbiniere and added the URL for HP C++ thanks to David Green)
• [38.5] Where can I get information about the C++ compiler from {Borland, IBM, Microsoft, Sun, etc.}?
  (corrected the URL for Microsoft Visual C++ thanks to Leila Rannanjarvi, and added the URL for Sun C++ thanks to Aryan Mirsepassi)
• [40.3] Are there any pretty-printers that reformat C++ source code?
  (added information about tgrind)

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Global changes:

• Added the (much requested!) one-click download feature. This automagically sends you a copy of the entire FAQ so you can browse off-line. There's a similar feature to get a copy of the "plaintext" version of the FAQ.
• Removed those pesky "hit counters" from each HTML page.
• Added nifty forward and backward links just after each FAQ.
• Added more nifty navigation aids at the bottom of each page.
• Renamed section [6] from "Management Issues" to "Big Picture Issues."

5 New FAQs:

• [4.47] What updates were made for the 01/97 release?
• [15.2] Why does my program go into an infinite loop when someone enters an invalid input character?
• [15.4] How does that funky while (std::cin >> foo) syntax work?
• [16.17] But the previous FAQ's code is SOOOO tricky and error prone! Isn't there a simpler way?
• [27.6] Is the ?: operator evil since it can be used to create unreadable code?

16 Changed FAQs:

• [1.3] Copying Permissions
  (simplified)
• [2.1] Where's the closest mirror site to access this document?
  (removed the "USA-2" site)
• [2.2] What happened to the one-click-download option?
  (rewrote and added a one-click feature to get .zip, .tar.Z or .tar.gz format)
• [5.1] What does IMHO mean? (or IMO, IMNSHO, FWIW, OTOH, etc.)?
  (added KUTGW (thanks to Bengt Richter))
• [15.8] How can I provide printing for my class Fred?
  (added note about cascading operator<< calls)
• [15.10] How can I provide input for my class Fred?
  (added note about cascading operator<< calls)
• [16.7] How can I convince my (older) compiler to automatically check new to see if it returns NULL?
  (fixed bugs: new handlers don't take arguments, thanks to Scott Aaron; changed set_new_hanlder to set_new_handler, thanks to Peter Andersson)
• [16.16] How do I allocate multidimensional arrays using new?
  (rewritten and expanded with a rectangular-matrix case)
• [18.1] What is "const correctness"?
  (rewrote because of helpful feedback from Nor Jaidi)
• [21.6] Is a Circle a kind-of an Ellipse?
  (added a caveat that setSize(x,y) isn't sacred)
• [21.7] Are there other options to the "Circle is/isnot kind-of Ellipse" dilemma?
  (added a caveat that setSize(x,y) isn't sacred)
• [21.8] But I have a Ph.D. in Mathematics, and I'm sure a Circle is a kind of an Ellipse! Does this mean Marshall Cline is stupid? Or that C++ is stupid? Or that OO is stupid?
  (added a caveat that setSize(x,y) isn't sacred)
• [23.5] When my base class's constructor calls a virtual function on its this object, why doesn't my derived class's override of that virtual function get invoked?
  (rewrote)
• [32.8] How can I pass an object of a C++ class to/from a C function?
  (added #ifndef FRED_H / #define FRED_H to code)
• [38.5] Where can I get information about the C++ compiler from {Borland, IBM, Microsoft, Sun, etc.}?
  (added HP C++)
• [40.5] Where can I get OS-specific questions answered (e.g., BC++, Windows, etc)?
  (added Borland C++ URLs thanks to Simon Edlund)

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4 New FAQs:

• [2.2] What happened to the one-click-download option?
• [4.48] What updates were made for the 11/96 release?
• [20.3] What's the difference between how virtual and non-virtual member functions are called?
• [38.3] How do I display text in the status bar using MFC?
  (with the help of Paul Ganney)

3 Changed FAQs:

• [8.5] How can you reseat a reference to make it refer to a different object?
  (changed last line from "pointer to const" to "const pointer" thanks to Neelesh Pandit)
• [27.13] Are there any other sources of coding standards?
  (rewrote and added more URLs)
• [38.9] If name mangling was standardized, could I link code compiled with compilers from different compiler vendors?
  (reworded and added v-table and v-pointer references)

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1 New FAQs:

• [4.49] What updates were made for the 10/96 release?

4 Changed FAQs:

• [5.9] Which newsgroup should I post my questions?
  (added comp.sys.mac.programmer.* and comp.sys.mac.oop.*)
• [16.7] How can I convince my (older) compiler to automatically check new to see if it returns NULL?
  (added comments on constructors of globals; thanks to William Carroll)
• [27.13] Are there any other sources of coding standards?
  (added URLs)
• [38.5] Where can I get information about the C++ compiler from {Borland, IBM, Microsoft, Sun, etc.}?
  (added URL for Metrowerks and Watcom compilers)

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12 New FAQs:

• [4.50] What updates were made for the 09/96 release?
• [5.1] What does IMHO mean? (or IMO, IMNSHO, FWIW, OTOH, etc.)?
• [5.2] How do I get other people to do my homework problem for me?
• [5.3] What should I do if I see someone else posting a homework problem?
  (with the help of Phil Staite)
• [18.4] What does "Fred const* p" mean?
• [18.5] What's the difference between "Fred const* p", "Fred* const p" and "Fred const* const p"?
• [18.6] What does "Fred const& x" mean?
• [18.7] Does "Fred& const x" make any sense?
• [18.8] What does "const X& x" mean?
• [18.16] Does "Fred const* p" mean that *p can't change?
• [27.13] Are there any other sources of coding standards?
• [38.4] How can I decompile an executable program back into C++ source code?
  (with the help of Phil Staite)

11 Changed FAQs:

• [8.5] How can you reseat a reference to make it refer to a different object?
  (added a cross reference regarding pointer to const)
• [9.6] How do you tell the compiler to make a non-member function inline?
  (strengthened the "Note:" at the end)
• [16.21] How can I force objects of my class to always be created via new rather than as locals or global/static objects?
  (reworded and added a paragraph on using friend to soften the original goal)
• [16.23] How do I provide reference counting with copy-on-write semantics?
  (added links to the self assignment discussion)
• [16.24] How do I provide reference counting with copy-on-write semantics for a hierarchy of classes?
  (added links to the self assignment discussion)
• [17.10] How should I handle resources if my constructors may throw exceptions?
  (added cross-references for reference-counted and remote smart-pointers)
• [21.2] Converting Derived* → Base* works OK; why doesn't Derived** → Base** work?
  (fixed a bug with help from William Wu)
• [22.4] What is a "pure virtual" member function?
  (reworded)
• [37.4] Where can I get help on how to use STL?
  (fixed the URL for Kenny Zalewski's STL guide)
• [38.5] Where can I get information about the C++ compiler from {Borland, IBM, Microsoft, Sun, etc.}?
  (added URLs for Silicon Graphics and Symantec compilers)
• [40.3] Are there any pretty-printers that reformat C++ source code?
  (added a URL for "V Communications")

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Global changes:

• Recently added/changed FAQs are now chained together using hyper-links (mainly for those who want to find out what has changed since the last time they read this document)
• Recently added FAQs are now decorated with  New!  ("recently" = "in the current or previous release")
• Recently changed FAQs are now decorated with  Updated!  ("recently" = "in the current or previous release")
• The look-and-feel of hyper-linked cross references is changed
  • The old look-and-feel "looks like this[4.51]"
  • The new look-and-feel "looks like this"
• Added section [12] Assignment operators
• Added section [28] Learning OO/C++

18 New FAQs:

• [4.51] What updates were made for the 08/96 release?
• [7.3] When is an interface "good"?
• [7.4] What is encapsulation?
• [7.5] How does C++ help with the tradeoff of safety vs. usability?
• [9.4] How can inline functions help with the tradeoff of safety vs. speed?
• [12.1] What is "self assignment"?
• [12.2] Why should I worry about "self assignment"?
• [12.3] OK, OK, already; I'll handle self-assignment. How do I do it?
• [13.3] What are some examples of operator overloading?
• [15.16] Why can't I open a file in a different directory such as "..\test.dat"?
• [28.1] What is mentoring?
• [28.2] Should I learn C before I learn OO/C++?
• [28.3] Should I learn Smalltalk before I learn OO/C++?
• [28.4] Should I buy one book, or several?
• [28.5] What are some best-of-breed C++ morality guides?
• [28.6] What are some best-of-breed C++ legality guides?
• [28.8] Are there other OO books that are relevant to OO/C++?
• [38.5] Where can I get information about the C++ compiler from {Borland, IBM, Microsoft, Sun, etc.}?

12 Changed FAQs:

• [6.5] Is C++ better than Ada? (or Visual Basic, C, FORTRAN, Pascal, Smalltalk, or any other language?)
  (reworded the last paragraph)
• [6.7] How long does it take to learn OO/C++?
  (added management-level hints for training developers in OO/C++)
• [9.5] Why should I use inline functions instead of plain old #define macros?
  (moved)
• [13.4] But operator overloading makes my class look ugly; isn't it supposed to make my code clearer?
  (rewritten)
• [13.10] How do I create a subscript operator for a Matrix class?
  (fixed a bug: "double** data_" is now "double* data_")
• [27.10] Are there any lint-like guidelines for C++?
  (added links to the self assignment discussion)
• [28.6] What are some best-of-breed C++ legality guides?
  (fixed the ISBN for Stan Lippman's book)
• [30.1] What's the difference between C++ and Smalltalk?
  (rewritten)
• [37.5] How can you tell if you have a dynamically typed C++ class library?
  (moved from the section on Smalltalk)
• [37.6] What is the NIHCL? Where can I get it?
  (moved from the section on Smalltalk)
• [37.9] Where can I get tons and tons of more information on C++ class libraries?
  (updated the URL)
• [39.7] Why can't the compiler find my header file in #include "c:\test.h" ?
  (updated to refer to [15.16])

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Global changes:

• Created an extensive subject index
• Added hyper-linked internal cross references throughout
• Changed the name of the document from On-Line C++ FAQs to C++ FAQs Lite
• Created section [23] Inheritance — what your mother never told you
• Split sections [10] Constructors and [11] Destructors into two distinct sections
• Major reorganization of sections [19] Inheritance — basics, [20] Inheritance — virtual functions, [21] Inheritance — proper inheritance and substitutability, and [22] Inheritance — abstract base classes (ABCs)
• Added example code throughout section [32] How to mix C and C++

50 New FAQs:

• [4.52] What updates were made for the 07/96 release?
• [5.5] What do I do if someone else posts a question that's already in the FAQ?
• [5.7] What makes a good Subject: line?
• [6.9] Are virtual functions (dynamic binding) central to OO/C++?
• [6.10] I'm from Missouri. Can you give me a simple reason why virtual functions (dynamic binding) make a big difference?
• [7.6] How can I prevent other programmers from violating encapsulation by seeing the private parts of my class?
• [7.8] Is Encapsulation a Security device?
• [10.4] Is the default constructor for Fred always Fred::Fred()?
• [10.5] Which constructor gets called when I create an array of Fred objects?
• [10.8] What is the "Named Constructor Idiom"?
• [10.11] Why can't I initialize my static member data in my constructor's initialization list?
• [11.2] What's the order that local objects are destructed?
• [11.3] What's the order that objects in an array are destructed?
• [11.4] Can I overload the destructor for my class?
• [11.5] Should I explicitly call a destructor on a local variable?
• [11.6] What if I want a local to "die" before the close } of the scope in which it was created? Can I call a destructor on a local if I really want to?
• [11.7] OK, OK already; I won't explicitly call the destructor of a local; but how do I handle the above situation?
• [11.8] What if I can't wrap the local in an artificial block?
• [11.9] But can I explicitly call a destructor if I've allocated my object with new?
• [11.10] What is "placement new" and why would I use it?
• [11.11] When I write a destructor, do I need to explicitly call the destructors for my member objects?
• [13.6] Can I overload operator== so it lets me compare two char[] using a string comparison?
• [13.10] How do I create a subscript operator for a Matrix class?
• [13.13] Should I design my classes from the outside (interfaces first) or from the inside (data first)?
• [15.10] How can I provide input for my class Fred?
• [16.6] Do I need to check for NULL after p = new Fred()?
• [16.7] How can I convince my (older) compiler to automatically check new to see if it returns NULL?
• [16.8] Do I need to check for NULL before delete p?
• [16.9] What are the two steps that happen when I say delete p?
• [16.10] In p = new Fred(), does the Fred memory "leak" if the Fred constructor throws an exception?
• [16.13] Can I drop the [] when deleteing an array of some built-in type (char, int, etc)?
• [16.14] After p = new Fred[n], how does the compiler know there are n objects to be destructed during delete[] p?
• [16.22] How do I do simple reference counting?
• [16.23] How do I provide reference counting with copy-on-write semantics?
• [16.24] How do I provide reference counting with copy-on-write semantics for a hierarchy of classes?
• [17.11] How do I change the string-length of an array of char to prevent memory leaks even if/when someone throws an exception?
• [18.15] Why does the compiler allow me to change an int after I've pointed at it with a int const*?
• [22.5] How do you define a copy constructor or assignment operator for a class that contains a pointer to a (abstract) base class?
• [23.10] What does it mean that the "virtual table" is an unresolved external?
• [27.12] Which is better: identifier names that_look_like_this or identifier names thatLookLikeThis?
  (with the help of James Robinson)
• [32.1] What do I need to know when mixing C and C++ code?
• [33.5] How can I avoid syntax errors when creating pointers to members?
• [33.6] How can I avoid syntax errors when calling a member function using a pointer-to-member-function?
• [34.2] How can I make a perl-like associative array in C++?
• [37.3] How can I find a Fred object in an STL container of Fred* such as std::vector<Fred*>?
• [37.9] Where can I get tons and tons of more information on C++ class libraries?
• [38.7] How do compilers use "over-allocation" to remember the number of elements in an allocated array?
• [38.8] How do compilers use an "associative array" to remember the number of elements in an allocated array?
• [39.7] Why can't the compiler find my header file in #include "c:\test.h" ?
• [39.8] What are the C++ scoping rules for for loops?

13 Changed FAQs:

• [5.4] How can I find out about general netiquette so I don't embarrass myself?
  (rewritten)
• [5.8] How do I post a question about code that doesn't work correctly?
  (rewritten)
• [7.9] What's the difference between the keywords struct and class?
  (rewritten)
• [10.12] Why are classes with static data members getting linker errors?
  (rewritten)
• [11.12] When I write a derived class's destructor, do I need to explicitly call the destructor for my base class?
  (added example code to illustrate the compiler's automagic calls to destructors of member objects and base class subobjects)
• [15.8] How can I provide printing for my class Fred?
  (added example code to illustrate operator<< on an ostream)
• [15.11] How can I provide printing for an entire hierarchy of classes?
  (moved from the section on Abstraction)
• [16.21] How can I force objects of my class to always be created via new rather than as locals or global/static objects?
  (added a reference to the Named Constructor Idiom)
• [32.2] How can I include a standard C header file in my C++ code?
  (rewritten)
• [32.3] How can I include a non-system C header file in my C++ code?
  (rewritten)
• [32.4] How can I modify my own C header files so it's easier to #include them in C++ code?
  (rewritten)
• [38.11] Is there a yacc-able C++ grammar?
  (updated the URL for the yacc-able C++ grammar)
• [40.3] Are there any pretty-printers that reformat C++ source code?
  (added "C-Clearly" and GNU indent to the list of pretty-printers)

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3 New FAQs:

• [4.53] What updates were made for the 06/96 release?
• [10.2] Is there any difference between List x; and List x();?
• [29.16] Why is floating point so inaccurate? Why doesn't this print 0.43?
  (with the help of Phil Staite)

13 Changed FAQs:

• [2.1] Where's the closest mirror site to access this document?
  (added Finland mirror site: www.utu.fi/~sisasa/oasis/cppfaq/)
• [3.1] Is there a C++ FAQ Book in addition to this on-line C++ FAQ?
  (fixed URL of book at Addison-Wesley)
• [18.1] What is "const correctness"?
  (added info on what happens when you try to pass a const parameter to a non-const function)
• [20.7] When should my destructor be virtual?
  (added the nitty-gritty rule for when you need to have a virtual destructor)
• [21.4] Is an array of Derived a kind-of array of Base?
  (fixed bug in code)
• [22.3] What is an ABC?
  (reworded)
• [22.4] What is a "pure virtual" member function?
  (reworded)
• [31.4] Should I normally use pointers to freestore allocated objects for my data members, or should I use "composition"?
  (reworded)
• [32.8] How can I pass an object of a C++ class to/from a C function?
  (fixed a bug in the code)
• [35.1] What's the idea behind templates?
  (reworded)
• [35.2] What's the syntax / semantics for a "class template"?
  (reworded)
• [40.2] Is there a TeX or LaTeX macro that fixes the spacing on "C++"?
  (added a new LaTeX macro)
• [40.3] Are there any pretty-printers that reformat C++ source code?
  (fixed URL of C++2LaTeX)

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Updated everything. Transformed the source from raw text to HTML. Reorganized, reworded, expanded, added example code, etc, etc.

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4 New FAQs:

• [4.55] What updates were made for the 04/96 release?
• [32.2] How can I include a standard C header file in my C++ code?
• [32.3] How can I include a non-system C header file in my C++ code?
• [32.4] How can I modify my own C header files so it's easier to #include them in C++ code?

3 Changed FAQs:

• [2.1] Where's the closest mirror site to access this document?
  (added European mirror site: www.informatik.uni-konstanz.de/~kuehl/cpp/cppfaq.htm)
• [16.15] Is it legal (and moral) for a member function to say delete this?
  (rewritten)
• [22.4] What is a "pure virtual" member function?
  (rewritten)

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3 New FAQs:

• [4.56] What updates were made for the 03/96 release?
• [6.5] Is C++ better than Ada? (or Visual Basic, C, FORTRAN, Pascal, Smalltalk, or any other language?)
• [34.4] How can I build a <favorite container> of objects of different types?
  (with the help of Phil Staite)

9 Changed FAQs:

• [6.13] Where can I get a copy of the ANSI/ISO C++ standard?
  (fixed the URL for the ANSI/ISO C++ Committee Draft)
• [15.1] Why should I use <iostream> instead of the traditional <cstdio>?
  (reworded)
• [16.3] Can I free() pointers allocated with new? Can I delete pointers allocated with malloc()?
  (added an admonition not to mix new and free() or malloc() and delete)
• [27.1] What are some good C++ coding standards?
  (reworded)
• [27.2] Are coding standards necessary? Are they sufficient?
  (reworded)
• [27.3] Should our organization determine coding standards from our C experience?
  (reworded)
• [27.10] Are there any lint-like guidelines for C++?
  (reworded)
• [30.3] Which is a better fit for C++: "static typing" or "dynamic typing"?
  (updated info on dynamic_cast and typeid())
• [40.3] Are there any pretty-printers that reformat C++ source code?
  (fixed URL of C++2LaTeX)

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5 New FAQs:

• [4.57] What updates were made for the 09/95 release?
• [15.13] How can I "reopen" std::cin and std::cout in binary mode?
• [37.4] Where can I get help on how to use STL?
• [37.7] Where can I ftp the code that accompanies "Numerical Recipes"?
• [37.8] Why is my executable so large?

4 Changed FAQs:

• [6.13] Where can I get a copy of the ANSI/ISO C++ standard?
  (added info on FTP access for the ANSI/ISO C++ Committee Draft)
• [8.3] What happens if you return a reference?
  (fixed a bug (variable i was not declared))
• [16.16] How do I allocate multidimensional arrays using new?
  (reworded)
• [37.2] Where can I get a copy of "STL"?
  (reworded)

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3 New FAQs:

• [4.58] What updates were made for the 06/95 release?
• [16.16] How do I allocate multidimensional arrays using new?
  (with the help of Doug Shapter)
• [33.3] Why do I keep getting compile errors (type mismatch) when I try to use a member function as an interrupt service routine?

2 Changed FAQs:

• [6.13] Where can I get a copy of the ANSI/ISO C++ standard?
  (fixed the US-Mail access for the ANSI/ISO C++ Committee Draft)
• [16.21] How can I force objects of my class to always be created via new rather than as locals or global/static objects?
  (rewritten)

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2 New FAQs:

• [4.59] What updates were made for the 04/95 release?
• [40.5] Where can I get OS-specific questions answered (e.g., BC++, Windows, etc)?

1 Changed FAQs:

• [37.6] What is the NIHCL? Where can I get it?
  (fixed the FTP address)

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4 New FAQs:

• [4.60] What updates were made for the 03/95 release?
• [15.5] Why does my input seem to process past the end of file?
• [15.6] Why is my program ignoring my input request after the first iteration?
• [16.15] Is it legal (and moral) for a member function to say delete this?

1 Changed FAQs:

• [40.4] Is there a C++-mode for GNU emacs? If so, where can I get it?
  (updated the information on cc-mode.el)

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2 New FAQs:

• [2.6] Where can I find the C++ FAQ translated into Chinese?
• [4.61] What updates were made for the 01/95 release?

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3 New FAQs:

• [4.62] What updates were made for the 12/94 release?
• [37.2] Where can I get a copy of "STL"?
• [38.9] If name mangling was standardized, could I link code compiled with compilers from different compiler vendors?

1 Changed FAQs:

• [24.3] Which should I prefer: composition or private inheritance?
  (reworded)

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3 New FAQs:

• [3.1] Is there a C++ FAQ Book in addition to this on-line C++ FAQ?
• [3.2] Is there a big difference between this on-line C++ FAQ and the C++ FAQ Book?
• [4.63] What updates were made for the 11/94 release?

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Rewrote most of the answers to provide general cleanup. Changed the quotation marks to "..." rather than `...' and/or ``...''. Sample code lines now start with a tab (no other lines starts with a tab). Everything was edited; minor modifications everywhere.

3 New FAQs:

• [4.64] What updates were made for the 08/94 release?
• [18.13] What do I do if I want a const member function to make an "invisible" change to a data member?
• [30.3] Which is a better fit for C++: "static typing" or "dynamic typing"?

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This document was originally written in 1991. I have no record of the specific changes that were made prior to 8/94.

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Revised Jul 28, 2011