std::bit_reverse - cppreference.com

template< class T >
constexpr T bit_reverse( T x ) noexcept;

Returns x with the order of the bits reversed.

This overload participates in overload resolution only if T is an unsigned integer type (that is, unsigned char, unsigned short, unsigned int, unsigned long, unsigned long long, or an extended unsigned integer type).

Parameters

Return value

x with the order of the bits reversed.

Notes

The function is typically implemented using an intrinsic such as Clang's __builtin_bitreverse, and has the same effect as the rbit instruction on ARM CPUs.

Example

#include <bit>
#include <cstdint>

static_assert(
    std::bit_reverse(
        std::uint8_t{0b1010'0011}) ==
        std::uint8_t{0b1100'0101} and
    std::bit_reverse(
        std::uint16_t{0b1010'0011}) ==
        std::uint16_t{0b1100'0101'0000'0000}
);

int main() {}

See also