ISO C++
library
IntroductionStatusImplementation StatusLicense
There are two licenses affecting GNU libstdc++: one for the code,
and one for the documentation.
There is a license section in the FAQ regarding common questions. If you have more
questions, ask the FSF or the gcc mailing list.
The Code: GPL
The source code is distributed under the GNU General Public License version 2,
with the so-called Runtime Exception
as follows (or see any header or implementation file):
As a special exception, you may use this file as part of a free software
library without restriction. Specifically, if other files instantiate
templates or use macros or inline functions from this file, or you compile
this file and link it with other files to produce an executable, this
file does not by itself cause the resulting executable to be covered by
the GNU General Public License. This exception does not however
invalidate any other reasons why the executable file might be covered by
the GNU General Public License.
Hopefully that text is self-explanatory. If it isn't, you need to speak
to your lawyer, or the Free Software Foundation.
The Documentation: GPL, FDL
The documentation shipped with the library and made available over
the web, excluding the pages generated from source comments, are
copyrighted by the Free Software Foundation, and placed under the
GNU Free Documentation
License version 1.2. There are no Front-Cover Texts, no
Back-Cover Texts, and no Invariant Sections.
For documentation generated by doxygen or other automated tools
via processing source code comments and markup, the original source
code license applies to the generated files. Thus, the doxygen
documents are licensed GPL.
If you plan on making copies of the documentation, please let us know.
We can probably offer suggestions.
BugsImplementation Bugs
Information on known bugs, details on efforts to fix them, and
fixed bugs are all available as part of the GCC bug tracking
system, bugzilla, with the
category set to libstdc++.
Standard Bugs
Everybody's got issues. Even the C++ Standard Library.
The Library Working Group, or LWG, is the ISO subcommittee responsible
for making changes to the library. They periodically publish an
Issues List containing problems and possible solutions. As they reach
a consensus on proposed solutions, we often incorporate the solution.
Here are the issues which have resulted in code changes to the library.
The links are to the specific defect reports from a partial
copy of the Issues List. You can read the full version online
at the ISO C++
Committee homepage, linked to on the
GCC "Readings"
page. If
you spend a lot of time reading the issues, we recommend downloading
the ZIP file and reading them locally.
(NB: partial copy means that not all
links within the lwg-*.html pages will work. Specifically,
links to defect reports that have not been accorded full DR
status will probably break. Rather than trying to mirror the
entire issues list on our overworked web server, we recommend
you go to the LWG homepage instead.)
If a DR is not listed here, we may simply not have gotten to
it yet; feel free to submit a patch. Search the include/bits
and src directories for appearances of
_GLIBCXX_RESOLVE_LIB_DEFECTS for examples
of style. Note that we usually do not make changes to the
code until an issue has reached DR status.
5:
string::compare specification questionableThis should be two overloaded functions rather than a single function.
17:
Bad bool parsingApparently extracting Boolean values was messed up...
19:
"Noconv" definition too vagueIf codecvt::do_in returns noconv there are
no changes to the values in [to, to_limit).
22:
Member open vs flagsRe-opening a file stream does not clear the state flags.
25:
String operator<< uses width() value wrongPadding issues.
48:
Use of non-existent exception constructorAn instance of ios_base::failure is constructed instead.
49:
Underspecification of ios_base::sync_with_stdioThe return type is the previous state of synchronization.
50:
Copy constructor and assignment operator of ios_baseThese members functions are declared private and are
thus inaccessible. Specifying the correct semantics of
"copying stream state" was deemed too complicated.
60:
What is a formatted input function?This DR made many widespread changes to basic_istream
and basic_ostream all of which have been implemented.
63:
Exception-handling policy for unformatted outputMake the policy consistent with that of formatted input, unformatted
input, and formatted output.
68:
Extractors for char* should store null at endAnd they do now. An editing glitch in the last item in the list of
[27.6.1.2.3]/7.
74:
Garbled text for codecvt::do_max_lengthThe text of the standard was gibberish. Typos gone rampant.
75:
Contradiction in codecvt::length's argument typesChange the first parameter to stateT& and implement
the new effects paragraph.
83:
string::npos vs. string::max_size()Safety checks on the size of the string should test against
max_size() rather than npos.
90:
Incorrect description of operator>> for stringsThe effect contain isspace(c,getloc()) which must be
replaced by isspace(c,is.getloc()).
91:
Description of operator>> and getline() for string<>
might cause endless loopThey behave as a formatted input function and as an unformatted
input function, respectively (except that getline is
not required to set gcount).
103:
set::iterator is required to be modifiable, but this allows
modification of keys.For associative containers where the value type is the same as
the key type, both iterator and const_iterator
are constant iterators.
109:
Missing binders for non-const sequence elementsThe binder1st and binder2nd didn't have an
operator() taking a non-const parameter.
110:
istreambuf_iterator::equal not constThis was not a const member function. Note that the DR says to
replace the function with a const one; we have instead provided an
overloaded version with identical contents.
117:
basic_ostream uses nonexistent num_put member functionsnum_put::put() was overloaded on the wrong types.
118:
basic_istream uses nonexistent num_get member functionsSame as 117, but for num_get::get().
129:
Need error indication from seekp() and seekg()These functions set failbit on error now.
136:
seekp, seekg setting wrong streams?seekp should only set the output stream, and
seekg should only set the input stream.
167:
Improper use of traits_type::length()op<< with a const char* was
calculating an incorrect number of characters to write.
169:
Bad efficiency of overflow() mandatedGrow efficiently the internal array object.
171:
Strange seekpos() semantics due to joint positionQuite complex to summarize...
181:
make_pair() unintended behaviorThis function used to take its arguments as reference-to-const, now
it copies them (pass by value).
195:
Should basic_istream::sentry's constructor ever set eofbit?Yes, it can, specifically if EOF is reached while skipping whitespace.
211:
operator>>(istream&, string&) doesn't set failbitIf nothing is extracted into the string, op>> now
sets failbit (which can cause an exception, etc., etc.).
214:
set::find() missing const overloadBoth set and multiset were missing
overloaded find, lower_bound, upper_bound, and equal_range functions
for const instances.
231:
Precision in iostream?For conversion from a floating-point type, str.precision()
is specified in the conversion specification.
233:
Insertion hints in associative containersImplement N1780, first check before then check after, insert as close
to hint as possible.
235:
No specification of default ctor for reverse_iteratorThe declaration of reverse_iterator lists a default constructor.
However, no specification is given what this constructor should do.
241:
Does unique_copy() require CopyConstructible and Assignable?Add a helper for forward_iterator/output_iterator, fix the existing
one for input_iterator/output_iterator to not rely on Assignability.
243:
get and getline when sentry reports failureStore a null character only if the character array has a non-zero size.
251:
basic_stringbuf missing allocator_typeThis nested typedef was originally not specified.
253:
valarray helper functions are almost entirely uselessMake the copy constructor and copy-assignment operator declarations
public in gslice_array, indirect_array, mask_array, slice_array; provide
definitions.
265:
std::pair::pair() effects overly restrictiveThe default ctor would build its members from copies of temporaries;
now it simply uses their respective default ctors.
266:
bad_exception::~bad_exception() missing Effects clauseThe bad_* classes no longer have destructors (they
are trivial), since no description of them was ever given.
271:
basic_iostream missing typedefsThe typedefs it inherits from its base classes can't be used, since
(for example) basic_iostream<T>::traits_type is ambiguous.
275:
Wrong type in num_get::get() overloadsSimilar to 118.
280:
Comparison of reverse_iterator to const reverse_iteratorAdd global functions with two template parameters.
(NB: not added for now a templated assignment operator)
292:
Effects of a.copyfmt (a)If (this == &rhs) do nothing.
300:
List::merge() specification incompleteIf (this == &x) do nothing.
303:
Bitset input operator underspecifiedBasically, compare the input character to
is.widen(0) and is.widen(1).
305:
Default behavior of codecvt<wchar_t, char,
mbstate_t>::length()Do not specify what codecvt<wchar_t, char,
mbstate_t>::do_length must return.
328:
Bad sprintf format modifier in
money_put<>::do_put()Change the format string to "%.0Lf".
365:
Lack of const-qualification in clause 27Add const overloads of is_open.
387:
std::complex over-encapsulatedAdd the real(T) and imag(T)
members; in C++0x mode, also adjust the existing
real() and imag() members and
free functions.
389:
Const overload of valarray::operator[] returns
by valueChange it to return a const T&.
402:
Wrong new expression in [some_]allocator::constructReplace "new" with "::new".
409:
Closing an fstream should clear the error stateHave open clear the error flags.
431:
Swapping containers with unequal allocatorsImplement Option 3, as per N1599.
432:
stringbuf::overflow() makes only one write position
availableImplement the resolution, beyond DR 169.
434:
bitset::to_string() hard to useAdd three overloads, taking fewer template arguments.
438:
Ambiguity in the "do the right thing" clauseImplement the resolution, basically cast less.
453:
basic_stringbuf::seekoff need not always fail for an empty streamDon't fail if the next pointer is null and newoff is zero.
455:
cerr::tie() and wcerr::tie() are overspecifiedInitialize cerr tied to cout and wcerr tied to wcout.
464:
Suggestion for new member functions in standard containersAdd data() to std::vector and
at(const key_type&) to std::map.
508:
Bad parameters for ranlux64_base_01Fix the parameters.
512:
Seeding subtract_with_carry_01 from a single unsigned longConstruct a linear_congruential engine and seed with it.
526:
Is it undefined if a function in the standard changes in
parameters?Use &value.
538:
241 again: Does unique_copy() require CopyConstructible
and Assignable?In case of input_iterator/output_iterator rely on Assignability of
input_iterator' value_type.
541:
shared_ptr template assignment and voidAdd an auto_ptr<void> specialization.
543:
valarray slice default constructorFollow the straightforward proposed resolution.
586:
string inserter not a formatted functionChange it to be a formatted output function (i.e. catch exceptions).
596:
27.8.1.3 Table 112 omits "a+" and "a+b" modesAdd the missing modes to fopen_mode.
660:
Missing bitwise operationsAdd the missing operations.
693:
std::bitset::all() missingAdd it, consistently with the discussion.
695:
ctype<char>::classic_table() not accessibleMake the member functions table and classic_table public.
761:
unordered_map needs an at() member functionIn C++0x mode, add at() and at() const.
775:
Tuple indexing should be unsigned?Implement the int -> size_t replacements.
778:
std::bitset does not have any constructor taking a string literalAdd it.
781:
std::complex should add missing C99 functionsIn C++0x mode, add std::proj.
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