std::bit_ceil

Since C++20

Header: <bit>

Calculates the smallest integral power of two that is not smaller than x.

# Declarations

template< class T >
constexpr T bit_ceil( T x );

(since C++20)

# Parameters

# Return value

The smallest integral power of two that is not smaller than x.

# Notes

Prior to P1956R1, the proposed name for this function template was ceil2.

# Example

#include <bit>
#include <bitset>
#include <iostream>
 
int main()
{
    using bin = std::bitset<8>;
    for (auto x{0U}; 0XA != x; ++x)
        std::cout << "bit_ceil( " << bin(x) << " ) = "
                  << bin(std::bit_ceil(x)) << '\n';
}

# See also