Standard library header <bit>

 

C++

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Standard Library Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

 

Standard Library headers

Language Support
<cstddef> <limits> <climits> <contract>	<cfloat> <cstdint> <new> <coroutine>	<typeinfo> <exception> <initializer_list> <version>	<csignal> <csetjmp> <cstdarg>
Concepts
<concepts>
Diagnostics
<stdexcept>	<cassert>	<cerrno>	<system_error>
General utilities
<utility> <memory> <memory_resource> <scoped_allocator>     <compare>	<bitset> <tuple> <optional> <any> <variant>	<type_traits> <ratio> <chrono> <typeindex> <functional>	<ctime> <cstdlib>
Strings
<string> <string_view>	<cctype> <cwctype>	<cwchar> <cuchar>	<cstring> <charconv>
Localization
<locale>	<codecvt>	<clocale>
Containers
<span> <array> <vector>	<deque> <forward_list> <list>	<map> <set> <queue>	<unordered_map> <unordered_set> <stack>
Iterators
<iterator>
Ranges
<ranges>
Algorithms
<algorithm>	<execution>
Numerics
<complex> <random>	<valarray> <numeric>	<cfenv> <cmath>	<bit>
Input/Output
<iosfwd> <ios> <iomanip> <streambuf>	<istream> <ostream> <iostream>	<sstream> <fstream> <syncstream>	<cstdio> <cinttypes> <strstream>
Regular expressions
<regex>
Filesystem support
<filesystem>
Thread support
<thread> <atomic>	<mutex> <shared_mutex>	<condition_variable> <future>
C compatibility
<ciso646> <cstdalign>	<cstdbool> <ccomplex>	<ctgmath>

 

This header is part of the numeric library.

Functions

bit_cast	reinterpret the object representation of one type as that of another (function template)
ispow2	checks if a number is an integral power of two (function template)
ceil2	finds the smallest integral power of two not less than the given value (function template)
floor2	finds the largest integral power of two not greater than the given value (function template)
log2p1	finds the smallest number of bits needed to represent the given value (function template)

Synopsis

namespace std {
    // bit_cast
    template<typename To, typename From>
    constexpr To bit_cast(const From& from) noexcept;
 
    // integral powers of 2
    template <class T>
    constexpr bool ispow2(T x) noexcept;
    template <class T>
    constexpr T ceil2(T x) noexcept;
    template <class T>
    constexpr T floor2(T x) noexcept;
    template <class T>
    constexpr T log2p1(T x) noexcept;
}