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Header files are annoying! Come over to the world of Rust!
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{{title|C++ Standard Library headers}}
 +
{{cpp/header/navbar}}
 +
 
 +
The interface of C++ standard library is defined by the following collection of headers.
 +
 
 +
{{dsc begin}}
 +
 
 +
{{dsc h1|Concepts library}}
 +
{{dsc inc|cpp/header/dsc concepts}}
 +
 
 +
{{dsc h1|Coroutines library}}
 +
{{dsc inc|cpp/header/dsc coroutine}}
 +
 
 +
{{dsc h1|Utilities library}}
 +
{{dsc inc|cpp/header/dsc any}}
 +
{{dsc inc|cpp/header/dsc bitset}}
 +
{{dsc inc|cpp/header/dsc chrono}}
 +
{{dsc inc|cpp/header/dsc compare}}
 +
{{dsc inc|cpp/header/dsc csetjmp}}
 +
{{dsc inc|cpp/header/dsc csignal}}
 +
{{dsc inc|cpp/header/dsc cstdarg}}
 +
{{dsc inc|cpp/header/dsc cstddef}}
 +
{{dsc inc|cpp/header/dsc cstdlib}}
 +
{{dsc inc|cpp/header/dsc ctime}}
 +
{{dsc inc|cpp/header/dsc expected}}
 +
{{dsc inc|cpp/header/dsc functional}}
 +
{{dsc inc|cpp/header/dsc initializer_list}}
 +
{{dsc inc|cpp/header/dsc optional}}
 +
{{dsc inc|cpp/header/dsc source_location}}
 +
{{dsc inc|cpp/header/dsc tuple}}
 +
{{dsc inc|cpp/header/dsc type_traits}}
 +
{{dsc inc|cpp/header/dsc typeindex}}
 +
{{dsc inc|cpp/header/dsc typeinfo}}
 +
{{dsc inc|cpp/header/dsc utility}}
 +
{{dsc inc|cpp/header/dsc variant}}
 +
{{dsc inc|cpp/header/dsc version}}
 +
 
 +
{{dsc h2|Dynamic memory management}}
 +
{{dsc inc|cpp/header/dsc memory}}
 +
{{dsc inc|cpp/header/dsc memory_resource}}
 +
{{dsc inc|cpp/header/dsc new}}
 +
{{dsc inc|cpp/header/dsc scoped_allocator}}
 +
 
 +
{{dsc h2|Numeric limits}}
 +
{{dsc inc|cpp/header/dsc cfloat}}
 +
{{dsc inc|cpp/header/dsc cinttypes}}
 +
{{dsc inc|cpp/header/dsc climits}}
 +
{{dsc inc|cpp/header/dsc cstdint}}
 +
{{dsc inc|cpp/header/dsc limits}}
 +
{{dsc inc|cpp/header/dsc stdfloat}}
 +
 
 +
{{dsc h2|Error handling}}
 +
{{dsc inc|cpp/header/dsc cassert}}
 +
{{dsc inc|cpp/header/dsc cerrno}}
 +
{{dsc inc|cpp/header/dsc exception}}
 +
{{dsc inc|cpp/header/dsc stacktrace}}
 +
{{dsc inc|cpp/header/dsc stdexcept}}
 +
{{dsc inc|cpp/header/dsc system_error}}
 +
 
 +
{{dsc h1|Strings library}}
 +
{{dsc inc|cpp/header/dsc cctype}}
 +
{{dsc inc|cpp/header/dsc charconv}}
 +
{{dsc inc|cpp/header/dsc cstring}}
 +
{{dsc inc|cpp/header/dsc cuchar}}
 +
{{dsc inc|cpp/header/dsc cwchar}}
 +
{{dsc inc|cpp/header/dsc cwctype}}
 +
{{dsc inc|cpp/header/dsc format}}
 +
{{dsc inc|cpp/header/dsc string}}
 +
{{dsc inc|cpp/header/dsc string_view}}
 +
 
 +
{{dsc h1|Containers library}}
 +
{{dsc inc|cpp/header/dsc array}}
 +
{{dsc inc|cpp/header/dsc deque}}
 +
{{dsc inc|cpp/header/dsc flat_map}}
 +
{{dsc inc|cpp/header/dsc flat_set}}
 +
{{dsc inc|cpp/header/dsc forward_list}}
 +
{{dsc inc|cpp/header/dsc list}}
 +
{{dsc inc|cpp/header/dsc map}}
 +
{{dsc inc|cpp/header/dsc mdspan}}
 +
{{dsc inc|cpp/header/dsc queue}}
 +
{{dsc inc|cpp/header/dsc set}}
 +
{{dsc inc|cpp/header/dsc span}}
 +
{{dsc inc|cpp/header/dsc stack}}
 +
{{dsc inc|cpp/header/dsc unordered_map}}
 +
{{dsc inc|cpp/header/dsc unordered_set}}
 +
{{dsc inc|cpp/header/dsc vector}}
 +
 
 +
{{dsc h1|Iterators library}}
 +
{{dsc inc|cpp/header/dsc iterator}}
 +
 
 +
{{dsc h1|Ranges library}}
 +
{{dsc inc|cpp/header/dsc generator}}
 +
{{dsc inc|cpp/header/dsc ranges}}
 +
 
 +
{{dsc h1|Algorithms library}}
 +
{{dsc inc|cpp/header/dsc algorithm}}
 +
{{dsc inc|cpp/header/dsc execution}}
 +
 
 +
{{dsc h1|Numerics library}}
 +
{{dsc inc|cpp/header/dsc bit}}
 +
{{dsc inc|cpp/header/dsc cfenv}}
 +
{{dsc inc|cpp/header/dsc cmath}}
 +
{{dsc inc|cpp/header/dsc complex}}
 +
{{dsc inc|cpp/header/dsc numbers}}
 +
{{dsc inc|cpp/header/dsc numeric}}
 +
{{dsc inc|cpp/header/dsc random}}
 +
{{dsc inc|cpp/header/dsc ratio}}
 +
{{dsc inc|cpp/header/dsc valarray}}
 +
 
 +
{{dsc h1|Localization library}}
 +
{{dsc inc|cpp/header/dsc clocale}}
 +
{{dsc inc|cpp/header/dsc codecvt}}
 +
{{dsc inc|cpp/header/dsc locale}}
 +
{{dsc inc|cpp/header/dsc text_encoding}}
 +
 
 +
{{dsc h1|Input/output library}}
 +
{{dsc inc|cpp/header/dsc cstdio}}
 +
{{dsc inc|cpp/header/dsc fstream}}
 +
{{dsc inc|cpp/header/dsc iomanip}}
 +
{{dsc inc|cpp/header/dsc ios}}
 +
{{dsc inc|cpp/header/dsc iosfwd}}
 +
{{dsc inc|cpp/header/dsc iostream}}
 +
{{dsc inc|cpp/header/dsc istream}}
 +
{{dsc inc|cpp/header/dsc ostream}}
 +
{{dsc inc|cpp/header/dsc print}}
 +
{{dsc inc|cpp/header/dsc spanstream}}
 +
{{dsc inc|cpp/header/dsc sstream}}
 +
{{dsc inc|cpp/header/dsc streambuf}}
 +
{{dsc inc|cpp/header/dsc strstream}}
 +
{{dsc inc|cpp/header/dsc syncstream}}
 +
 
 +
{{dsc h1|Filesystem library}}
 +
{{dsc inc|cpp/header/dsc filesystem}}
 +
 
 +
{{dsc h1|Regular Expressions library}}
 +
{{dsc inc|cpp/header/dsc regex}}
 +
 
 +
{{dsc h1|Atomic Operations library}}
 +
{{dsc inc|cpp/header/dsc atomic}}
 +
 
 +
{{dsc h1|Thread support library}}
 +
{{dsc inc|cpp/header/dsc barrier}}
 +
{{dsc inc|cpp/header/dsc condition_variable}}
 +
{{dsc inc|cpp/header/dsc future}}
 +
{{dsc inc|cpp/header/dsc hazard_pointer}}
 +
{{dsc inc|cpp/header/dsc latch}}
 +
{{dsc inc|cpp/header/dsc mutex}}
 +
{{dsc inc|cpp/header/dsc rcu}}
 +
{{dsc inc|cpp/header/dsc semaphore}}
 +
{{dsc inc|cpp/header/dsc shared_mutex}}
 +
{{dsc inc|cpp/header/dsc stop_token}}
 +
{{dsc inc|cpp/header/dsc thread}}
 +
{{dsc end}}
 +
 
 +
===C compatibility headers===
 +
For some of the C standard library headers of the form {{tt|''xxx''.h}}, the C++ standard library both includes an identically-named header and another header of the form {{tt|c''xxx''}} (all meaningful {{tt|c''xxx''}} headers are listed above). The intended use of headers of form {{tt|''xxx''.h}} is for interoperability only. It is possible that C++ source files need to include one of these headers in order to be valid ISO C. Source files that are not intended to also be valid ISO C should not use any of the C headers.
 +
 
 +
With the exception of {{rlt|ccomplex|complex.h}}{{mark unreviewed dr|LWG}}<!--LWG 551/2536-->, each {{tt|''xxx''.h}} header included in the C++ standard library places in the global namespace each name that the corresponding {{tt|c''xxx''}} header would have placed in the {{c|std}} namespace.
 +
 
 +
These headers are allowed to also declare the same names in the {{c|std}} namespace, and the corresponding {{tt|c''xxx''}} headers are allowed to also declare the same names in the global namespace: including {{header|cstdlib}} definitely provides {{c|std::malloc}} and may also provide {{c|::malloc}}. Including {{header|stdlib.h|lang=c}} definitely provides {{c|::malloc}} and may also provide {{c|std::malloc}}. This applies even to functions and function overloads that are not part of C standard library.
 +
 
 +
Notes: {{tt|''xxx''.h}} headers are deprecated in C++98 and undeprecated in C++23. These headers are discouraged for pure C++ code, but not subject to future removal.
 +
 
 +
{{dsc begin}}
 +
{{dsc inc|cpp/header/dsc assert.h}}
 +
{{dsc inc|cpp/header/dsc ctype.h}}
 +
{{dsc inc|cpp/header/dsc errno.h}}
 +
{{dsc inc|cpp/header/dsc fenv.h}}
 +
{{dsc inc|cpp/header/dsc float.h}}
 +
{{dsc inc|cpp/header/dsc inttypes.h}}
 +
{{dsc inc|cpp/header/dsc limits.h}}
 +
{{dsc inc|cpp/header/dsc locale.h}}
 +
{{dsc inc|cpp/header/dsc math.h}}
 +
{{dsc inc|cpp/header/dsc setjmp.h}}
 +
{{dsc inc|cpp/header/dsc signal.h}}
 +
{{dsc inc|cpp/header/dsc stdarg.h}}
 +
{{dsc inc|cpp/header/dsc stddef.h}}
 +
{{dsc inc|cpp/header/dsc stdint.h}}
 +
{{dsc inc|cpp/header/dsc stdio.h}}
 +
{{dsc inc|cpp/header/dsc stdlib.h}}
 +
{{dsc inc|cpp/header/dsc string.h}}
 +
{{dsc inc|cpp/header/dsc time.h}}
 +
{{dsc inc|cpp/header/dsc uchar.h}}
 +
{{dsc inc|cpp/header/dsc wchar.h}}
 +
{{dsc inc|cpp/header/dsc wctype.h}}
 +
{{dsc end}}
 +
 
 +
====Special C compatibility headers====
 +
The header {{header|stdatomic.h|lang=c}} declares names which are also provided in the C standard library, and defines the {{tt|_Atomic}} macro which is a [[c/keyword/_Atomic|keyword]] in C. Unlike other {{tt|''xxx''.h}} headers, corresponding {{tt|<cstdatomic>}} is not provided.
 +
 
 +
{{dsc begin}}
 +
{{dsc inc|cpp/header/dsc stdatomic.h}}
 +
{{dsc end}}
 +
 
 +
====Empty C headers====
 +
The headers {{header|complex.h|lang=c}}, {{header|ccomplex}}, {{header|tgmath.h|lang=c}}, and {{header|ctgmath}} do not contain any content from the C standard library and instead merely include other headers from the C++ standard library.
 +
 
 +
{{dsc begin}}
 +
{{dsc inc|cpp/header/dsc ccomplex}}
 +
{{dsc inc|cpp/header/dsc complex.h}}
 +
{{dsc inc|cpp/header/dsc ctgmath}}
 +
{{dsc inc|cpp/header/dsc tgmath.h}}
 +
{{dsc end}}
 +
 
 +
====Meaningless C headers====
 +
The headers {{header|ciso646}}, {{header|cstdalign}}, and {{header|cstdbool}} are meaningless in C++ because the macros they provide in C are language keywords in C++.
 +
 
 +
{{dsc begin}}
 +
{{dsc inc|cpp/header/dsc ciso646}}
 +
{{dsc inc|cpp/header/dsc cstdalign}}
 +
{{dsc inc|cpp/header/dsc cstdbool}}
 +
{{dsc inc|cpp/header/dsc iso646.h}}
 +
{{dsc inc|cpp/header/dsc stdalign.h}}
 +
{{dsc inc|cpp/header/dsc stdbool.h}}
 +
{{dsc end}}
 +
 
 +
====Unsupported C headers====
 +
The C headers {{rev inl|until=c++23|{{header|stdatomic.h|lang=c}},}} {{header|stdnoreturn.h|lang=c}}, and {{header|threads.h|lang=c}} are not included in C++ and have no {{tt|c''xxx''}} equivalents.
 +
 
 +
==={{rl|experimental|Experimental libraries}}===
 +
[[cpp/experimental|C++ TR's/TS's]] also define several collections of headers.
 +
 
 +
===See also===
 +
{{dsc begin}}
 +
{{dsc see c|c/header|C Standard Library headers|nomono=true}}
 +
{{dsc end}}
 +
 
 +
{{langlinks|ar|de|es|fr|it|ja|pt|ru|zh}}

Revision as of 13:55, 7 October 2023

 
C++
 
Standard library headers
 

The interface of C++ standard library is defined by the following collection of headers.

Contents

Concepts library

(C++20)
 Fundamental library concepts[edit]

Coroutines library

(C++20)
 Coroutine support library[edit]

Utilities library

(C++17)
 std::any class[edit]
std::bitset class template[edit]
(C++11)
 C++ time utilities[edit]
(C++20)
 Three-way comparison operator support[edit]
Macro (and function) that saves (and jumps) to an execution context[edit]
Functions and macro constants for signal management[edit]
Handling of variable length argument lists[edit]
Standard macros and typedefs[edit]
General purpose utilities: program control, dynamic memory allocation, random numbers, sort and search[edit]
C-style time/date utilities[edit]
(C++23)
 std::expected class template[edit]
Function objects, Function invocations, Bind operations and Reference wrappers[edit]
(C++11)
 std::initializer_list class template[edit]
(C++17)
 std::optional class template[edit]
(C++20)
 Supplies means to obtain source code location[edit]
(C++11)
 std::tuple class template[edit]
(C++11)
 Compile-time type information utilities[edit]
(C++11)
 std::type_index[edit]
Runtime type information utilities[edit]
Various utility components[edit]
(C++17)
 std::variant class template[edit]
(C++20)
 Supplies macros for verifying implementation status of library[edit]
Dynamic memory management
High-level memory management utilities[edit]
(C++17)
 Polymorphic allocators and memory resources[edit]
Low-level memory management utilities[edit]
(C++11)
 Nested allocator class[edit]
Numeric limits
Limits of floating-point types[edit]
(C++11)
 Formatting macros, intmax_t and uintmax_t math and conversions[edit]
Limits of integral types[edit]
(C++11)
 Fixed-width integer types and limits of other types[edit]
Query properties of arithmetic types[edit]
(C++23)
 Fixed-width floating-point types[edit]
Error handling
Conditionally compiled macro that compares its argument to zero[edit]
Macro containing the last error number[edit]
Exception handling utilities[edit]
(C++23)
 Stacktrace library[edit]
Standard exception types[edit]
(C++11)
 Defines std::error_code, a platform-dependent error code[edit]

Strings library

 Functions to determine the category of narrow characters[edit]
(C++17)
 std::to_chars and std::from_chars[edit]
Various narrow character string handling functions[edit]
(C++11)
 C-style Unicode character conversion functions[edit]
Various wide and multibyte string handling functions[edit]
Functions to determine the category of wide characters[edit]
(C++20)
 Formatting library including std::format[edit]
std::basic_string class template[edit]
(C++17)
 std::basic_string_view class template[edit]

Containers library

(C++11)
 std::array container[edit]
std::deque container[edit]
(C++23)
 std::flat_map and std::flat_multimap container adaptors[edit]
(C++23)
 std::flat_set and std::flat_multiset container adaptors[edit]
(C++11)
 std::forward_list container[edit]
std::list container[edit]
std::map and std::multimap associative containers[edit]
(C++23)
 std::mdspan view[edit]
std::queue and std::priority_queue container adaptors[edit]
std::set and std::multiset associative containers[edit]
(C++20)
 std::span view[edit]
std::stack container adaptor[edit]
(C++11)
 std::unordered_map and std::unordered_multimap unordered associative containers[edit]
(C++11)
 std::unordered_set and std::unordered_multiset unordered associative containers[edit]
std::vector container[edit]

Iterators library

 Range iterators[edit]

Ranges library

(C++23)
 std::generator class template[edit]
(C++20)
 Range access, primitives, requirements, utilities and adaptors[edit]

Algorithms library

 Algorithms that operate on ranges[edit]
(C++17)
 Predefined execution policies for parallel versions of the algorithms and execution control components(since C++26)[edit]

Numerics library

(C++20)
 Bit manipulation functions[edit]
(C++11)
 Floating-point environment access functions[edit]
Common mathematics functions[edit]
Complex number type[edit]
(C++20)
 Math constants[edit]
Numeric operations on values in ranges[edit]
(C++11)
 Random number generators and distributions[edit]
(C++11)
 Compile-time rational arithmetic[edit]
Class for representing and manipulating arrays of values[edit]

Localization library

 C localization utilities[edit]
(C++11)(deprecated in C++17)(removed in C++26)
 Unicode conversion facilities[edit]
Localization utilities[edit]
(C++26)
 Text encoding identifications[edit]

Input/output library

 C-style input-output functions[edit]
std::basic_fstream, std::basic_ifstream, std::basic_ofstream class templates and typedefs[edit]
Helper functions to control the format of input and output[edit]
std::ios_base class, std::basic_ios class template and typedefs[edit]
Forward declarations of all classes in the input/output library[edit]
Several standard stream objects[edit]
std::basic_istream class template and typedefs[edit]
std::basic_ostream, std::basic_iostream class templates and typedefs[edit]
(C++23)
 Formatted output library including std::print[edit]
(C++23)
 std::basic_spanstream, std::basic_ispanstream, std::basic_ospanstream class templates and typedefs[edit]
std::basic_stringstream, std::basic_istringstream, std::basic_ostringstream class templates and typedefs[edit]
std::basic_streambuf class template[edit]
(deprecated in C++98)(removed in C++26)
 std::strstream, std::istrstream, std::ostrstream[edit]
(C++20)
 std::basic_osyncstream, std::basic_syncbuf and typedefs[edit]

Filesystem library

(C++17)
 std::filesystem::path class and supporting functions[edit]

Regular Expressions library

(C++11)
 Classes, algorithms and iterators to support regular expression processing[edit]

Atomic Operations library

(C++11)
 Atomic operations library[edit]

Thread support library

(C++20)
 Barriers[edit]
(C++11)
 Thread waiting conditions[edit]
(C++11)
 Primitives for asynchronous computations[edit]
(C++26)
 Hazard pointers[edit]
(C++20)
 Latches[edit]
(C++11)
 Mutual exclusion primitives[edit]
(C++26)
 Read-copy update mechanisms[edit]
(C++20)
 Semaphores[edit]
(C++14)
 Shared mutual exclusion primitives[edit]
(C++20)
 Stop tokens for std::jthread[edit]
(C++11)
 std::thread class and supporting functions[edit]

C compatibility headers

For some of the C standard library headers of the form xxx.h, the C++ standard library both includes an identically-named header and another header of the form cxxx (all meaningful cxxx headers are listed above). The intended use of headers of form xxx.h is for interoperability only. It is possible that C++ source files need to include one of these headers in order to be valid ISO C. Source files that are not intended to also be valid ISO C should not use any of the C headers.

With the exception of complex.h, each xxx.h header included in the C++ standard library places in the global namespace each name that the corresponding cxxx header would have placed in the std namespace.

These headers are allowed to also declare the same names in the std namespace, and the corresponding cxxx headers are allowed to also declare the same names in the global namespace: including <cstdlib> definitely provides std::malloc and may also provide ::malloc. Including <stdlib.h> definitely provides ::malloc and may also provide std::malloc. This applies even to functions and function overloads that are not part of C standard library.

Notes: xxx.h headers are deprecated in C++98 and undeprecated in C++23. These headers are discouraged for pure C++ code, but not subject to future removal.

Behaves same as <cassert>[edit]
Behaves as if each name from <cctype> is placed in global namespace[edit]
Behaves same as <cerrno>[edit]
(C++11)
 Behaves as if each name from <cfenv> is placed in global namespace[edit]
Behaves same as <cfloat>[edit]
(C++11)
 Behaves as if each name from <cinttypes> is placed in global namespace[edit]
Behaves same as <climits>[edit]
Behaves as if each name from <clocale> is placed in global namespace[edit]
Behaves as if each name from <cmath> is placed in global namespace,
except for names of mathematical special functions[edit]
Behaves as if each name from <csetjmp> is placed in global namespace[edit]
Behaves as if each name from <csignal> is placed in global namespace[edit]
Behaves as if each name from <cstdarg> is placed in global namespace[edit]
Behaves as if each name from <cstddef> is placed in global namespace,
except for names of std::byte and related functions[edit]
(C++11)
 Behaves as if each name from <cstdint> is placed in global namespace[edit]
Behaves as if each name from <cstdio> is placed in global namespace[edit]
Behaves as if each name from <cstdlib> is placed in global namespace[edit]
Behaves as if each name from <cstring> is placed in global namespace[edit]
Behaves as if each name from <ctime> is placed in global namespace[edit]
(C++11)
 Behaves as if each name from <cuchar> is placed in global namespace[edit]
Behaves as if each name from <cwchar> is placed in global namespace[edit]
Behaves as if each name from <cwctype> is placed in global namespace[edit]

Special C compatibility headers

The header <stdatomic.h> declares names which are also provided in the C standard library, and defines the _Atomic macro which is a keyword in C. Unlike other xxx.h headers, corresponding <cstdatomic> is not provided.

(C++23)
 Defines _Atomic and provides corresponding components in the C standard library[edit]

Empty C headers

The headers <complex.h>, <ccomplex>, <tgmath.h>, and <ctgmath> do not contain any content from the C standard library and instead merely include other headers from the C++ standard library.

(C++11)(deprecated in C++17)(removed in C++20)
 Simply includes the header <complex>[edit]
(C++11)
 Simply includes the header <complex>[edit]
(C++11)(deprecated in C++17)(removed in C++20)
 Simply includes the headers <complex> and <cmath>: the overloads equivalent to the contents of the C header tgmath.h are already provided by those headers[edit]
(C++11)
 Simply includes the headers <complex> and <cmath>[edit]

Meaningless C headers

The headers <ciso646>, <cstdalign>, and <cstdbool> are meaningless in C++ because the macros they provide in C are language keywords in C++.

(removed in C++20)
 Empty header. The macros that appear in iso646.h in C are keywords in C++[edit]
(C++11)(deprecated in C++17)(removed in C++20)
 Defines one compatibility macro constant[edit]
(C++11)(deprecated in C++17)(removed in C++20)
 Defines one compatibility macro constant[edit]
Has no effect[edit]
(C++11)
 Defines one compatibility macro constant[edit]
(C++11)
 Defines one compatibility macro constant[edit]

Unsupported C headers

The C headers <stdatomic.h>,(until C++23) <stdnoreturn.h>, and <threads.h> are not included in C++ and have no cxxx equivalents.

Experimental libraries

C++ TR's/TS's also define several collections of headers.

See also

C documentation for C Standard Library headers
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