Bit manipulation (since C++20)

 

C++

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Freestanding and hosted

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Feature test macros(C++20)

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Concepts library(C++20)

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Symbols index

External libraries

 

Utilities library

Language support Type support (basic types, RTTI) Library feature-test macros(C++20) Program utilities Variadic functions initializer_list (C++11) is_constant_evaluated (C++20) is_within_lifetime (C++26) source_location (C++20) Coroutine support(C++20) Contract support(C++26) Three-way comparison three_way_comparablethree_way_comparable_with (C++20)(C++20) strong_ordering (C++20) weak_ordering (C++20) partial_ordering (C++20) common_comparison_category (C++20) compare_three_way_result (C++20) compare_three_way (C++20) strong_order (C++20) weak_order (C++20) partial_order (C++20) compare_strong_order_fallback (C++20) compare_weak_order_fallback (C++20) compare_partial_order_fallback (C++20)   is_eqis_ltis_lteq (C++20)(C++20)(C++20)   is_neqis_gtis_gteq (C++20)(C++20)(C++20)

General utilities Function objects Bit manipulation(C++20) bitset hash (C++11) Relational operators(deprecated in C++20) rel_ops::operator!=rel_ops::operator>    rel_ops::operator<=rel_ops::operator>= Integer comparison functions cmp_equalcmp_lesscmp_less_than (C++20)(C++20)(C++20)   cmp_not_equalcmp_greatercmp_greater_than (C++20)(C++20)(C++20) in_range (C++20) Swap and type operations swap ranges::swap (C++20) exchange (C++14) declval (C++11) to_underlying (C++23) forward (C++11) forward_like (C++23) move (C++11) move_if_noexcept (C++11) as_const (C++17) Common vocabulary types pair tuple (C++11) optional (C++17) any (C++17) variant (C++17) tuple_size (C++11) tuple_element (C++11) apply (C++17) make_from_tuple (C++17) expected (C++23)

 

Bit manipulation

bit_cast (C++20)

byteswap (C++23)

Integral powers of 2

has_single_bit (C++20)

bit_ceil (C++20)

bit_floor (C++20)

bit_width (C++20)

Rotating

rotl (C++20)

rotr (C++20)

Counting

countl_zero (C++20)

countl_one (C++20)

countr_zero (C++20)

countr_one (C++20)

popcount (C++20)

Endian

endian (C++20)

 

Provides several function templates to access, manipulate, and process individual bits and bit sequences.

Defined in header <bit>
Defined in namespace std
bit_cast (C++20)	reinterpret the object representation of one type as that of another (function template)
byteswap (C++23)	reverses the bytes in the given integer value (function template)
Integral powers of 2
has_single_bit (C++20)	checks if a number is an integral power of 2 (function template)
bit_ceil (C++20)	finds the smallest integral power of 2 not less than the given value (function template)
bit_floor (C++20)	finds the largest integral power of 2 not greater than the given value (function template)
bit_width (C++20)	finds the smallest number of bits needed to represent the given value (function template)
Rotating
rotl (C++20)	computes the result of bitwise left-rotation (function template)
rotr (C++20)	computes the result of bitwise right-rotation (function template)
Counting
countl_zero (C++20)	counts the number of consecutive ​0​ bits, starting from the most significant bit (function template)
countl_one (C++20)	counts the number of consecutive 1 bits, starting from the most significant bit (function template)
countr_zero (C++20)	counts the number of consecutive ​0​ bits, starting from the least significant bit (function template)
countr_one (C++20)	counts the number of consecutive 1 bits, starting from the least significant bit (function template)
popcount (C++20)	counts the number of 1 bits in an unsigned integer (function template)
Endian
endian (C++20)	indicates the endianness of scalar types (enum)

Notes

Feature-test macro	Value	Std	Feature
__cpp_lib_bit_cast	201806L	(C++20)	std::bit_cast
__cpp_lib_bitops	201907L	(C++20)	Bit operations
__cpp_lib_int_pow2	202002L	(C++20)	Integral power-of-2 operations
__cpp_lib_byteswap	202110L	(C++23)	std::byteswap

See also

C documentation for Bit manipulation