Standard library header <bitset>

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros(C++20)

Language support library

Concepts library(C++20)

Diagnostics library

Memory management library

Metaprogramming library(C++11)

General utilities library

Containers library

Iterators library

Ranges library(C++20)

Algorithms library

Strings library

Text processing library

Numerics library

Date and time library

Input/output library

Filesystem library(C++17)

Concurrency support library(C++11)

Execution control library(C++26)

Technical specifications

Symbols index

External libraries

 

Standard library headers

Language support <cfloat> <climits> <compare>(C++20) <contracts>(C++26) <coroutine>(C++20) <csetjmp> <csignal> <cstdarg> <cstddef> <cstdint>(C++11) <cstdlib> <exception> <initializer_list>(C++11)    <limits> <new> <source_location>(C++20) <stdfloat>(C++23) <typeinfo> <version>(C++20) Concepts <concepts>(C++20) Diagnostics <cassert> <cerrno> <debugging>(C++26) <stacktrace>(C++23) <stdexcept> <system_error>(C++11) Memory management <memory> <memory_resource>(C++17) <scoped_allocator>(C++11) Metaprogramming <type_traits>(C++11) <ratio>(C++11)

General utilities <any>(C++17) <bitset> <bit>(C++20) <charconv>(C++17) <expected>(C++23) <format>(C++20) <functional> <optional>(C++17) <stdbit.h>(C++26) <tuple>(C++11) <typeindex>(C++11) <utility> <variant>(C++17) Containers <array>(C++11) <deque> <flat_map>(C++23) <flat_set>(C++23) <forward_list>(C++11) <hive>(C++26) <inplace_vector>(C++26)    <list> <map> <mdspan>(C++23) <queue> <set> <span>(C++20) <stack> <unordered_map>(C++11) <unordered_set>(C++11) <vector> Iterators <iterator> Ranges <generator>(C++23) <ranges>(C++20)

Algorithms <algorithm> <numeric> Strings <cctype> <cstring> <cuchar>(C++11) <cwchar> <cwctype> <string_view>(C++17) <string> Text processing <clocale> <codecvt>(C++11/17/26*) <locale> <regex>(C++11) <text_encoding>(C++26)    Numerics <cfenv>(C++11) <cmath> <complex> <linalg>(C++26) <numbers>(C++20) <random>(C++11) <simd>(C++26) <stdckdint.h>(C++26) <valarray> Time <chrono>(C++11) <ctime> C compatibility <ccomplex>(C++11/17/20*) <ciso646>(until C++20) <cstdalign>(C++11/17/20*) <cstdbool>(C++11/17/20*) <ctgmath>(C++11/17/20*)

Input/output <cinttypes>(C++11) <cstdio> <filesystem>(C++17) <fstream> <iomanip> <iosfwd> <iostream> <ios> <istream> <ostream> <print>(C++23) <spanstream>(C++23) <sstream> <streambuf> <strstream>(C++98/26*) <syncstream>(C++20) Concurrency support <atomic>(C++11) <barrier>(C++20) <condition_variable>(C++11) <future>(C++11) <hazard_pointer>(C++26) <latch>(C++20) <mutex>(C++11) <rcu>(C++26) <semaphore>(C++20) <shared_mutex>(C++14) <stdatomic.h>(C++23) <stop_token>(C++20) <thread>(C++11) Execution support <execution>(C++17)

 

This header is part of the general utility library.

Includes
<string>	std::basic_string class template
<iosfwd>	Forward declarations of all classes in the input/output library
Classes
bitset	implements constant length bit array (class template)
std::hash<std::bitset> (C++11)	hash support for std::bitset (class template specialization)
Forward declarations
Defined in header <functional>
hash (C++11)	hash function object (class template)
Functions
operator&operator|operator^	performs binary logic operations on bitsets (function template)
operator<<operator>>	performs stream input and output of bitsets (function template)

Synopsis

#include <string>#include <iosfwd> // for istream, ostream   namespace std {template<size_t N>class bitset;   // bitset operatorstemplate<size_t N>constexpr bitset<N> operator&(const bitset<N>&, const bitset<N>&)noexcept;template<size_t N>constexpr bitset<N> operator|(const bitset<N>&, const bitset<N>&)noexcept;template<size_t N>constexpr bitset<N> operator^(const bitset<N>&, const bitset<N>&)noexcept;template<class CharT, class Traits, size_t N> basic_istream<CharT, Traits>& operator>>(basic_istream<CharT, Traits>& is, bitset<N>& x);template<class CharT, class Traits, size_t N> basic_ostream<CharT, Traits>& operator<<(basic_ostream<CharT, Traits>& os, const bitset<N>& x);}

Class template std::bitset

namespace std {template<size_t N>class bitset {public:// bit referenceclass reference {public:constexpr reference(const reference&)=default;constexpr ~reference();constexpr reference& operator=(bool x)noexcept;// for b[i] = x;constexpr reference& operator=(const reference&)noexcept;// for b[i] = b[j];constexprbool operator~()constnoexcept;// flips the bitconstexpr operator bool()constnoexcept;// for x = b[i];constexpr reference& flip()noexcept;// for b[i].flip();};   // constructorsconstexpr bitset()noexcept;constexpr bitset(unsignedlonglong val)noexcept;template<class CharT, class Traits, class Allocator>constexprexplicit bitset(const basic_string<CharT, Traits, Allocator>& str, typename basic_string<CharT, Traits, Allocator>::size_type pos =0, typename basic_string<CharT, Traits, Allocator>::size_type n = basic_string<CharT, Traits, Allocator>::npos, CharT zero = CharT('0'), CharT one = CharT('1'));template<class CharT, class Traits>constexprexplicit bitset( basic_string_view<CharT, Traits> str, typename basic_string_view<CharT, Traits>::size_type pos =0, typename basic_string_view<CharT, Traits>::size_type n = basic_string_view<CharT, Traits>::npos, CharT zero = CharT('0'), CharT one = CharT('1'));template<class CharT>constexprexplicit bitset(const CharT* str, typename basic_string_view<CharT>::size_type n = basic_string_view<CharT>::npos, CharT zero = CharT('0'), CharT one = CharT('1'));   // bitset operationsconstexpr bitset& operator&=(const bitset& rhs)noexcept;constexpr bitset& operator|=(const bitset& rhs)noexcept;constexpr bitset& operator^=(const bitset& rhs)noexcept;constexpr bitset& operator<<=(size_t pos)noexcept;constexpr bitset& operator>>=(size_t pos)noexcept;constexpr bitset operator<<(size_t pos)constnoexcept;constexpr bitset operator>>(size_t pos)constnoexcept;constexpr bitset& set()noexcept;constexpr bitset& set(size_t pos, bool val =true);constexpr bitset& reset()noexcept;constexpr bitset& reset(size_t pos);constexpr bitset operator~()constnoexcept;constexpr bitset& flip()noexcept;constexpr bitset& flip(size_t pos);   // element accessconstexprbool operator[](size_t pos)const;constexpr reference operator[](size_t pos);   constexprunsignedlong to_ulong()const;constexprunsignedlonglong to_ullong()const;template<class CharT =char, class Traits = char_traits<CharT>, class Allocator = allocator<CharT>>constexpr basic_string<CharT, Traits, Allocator> to_string(CharT zero = CharT('0'), CharT one = CharT('1'))const;   // observersconstexpr size_t count()constnoexcept;constexpr size_t size()constnoexcept;constexprbool operator==(const bitset& rhs)constnoexcept;constexprbool test(size_t pos)const;constexprbool all()constnoexcept;constexprbool any()constnoexcept;constexprbool none()constnoexcept;};   // hash supporttemplate<class T>struct hash;template<size_t N>struct hash<bitset<N>>;}

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 4140	C++98	the synopsis contains a declaration of the default constructor of std::bitset<N>::reference	removed the declaration