keep_n_lsb.hpp

#pragma once
#include <cstddef>
 
namespace numeric {
 
template <typename T> inline T keep_n_lsb(T const& input, size_t num_bits)
{
    return num_bits >= sizeof(T) * 8 ? input : input & ((T(1) << num_bits) - 1);
}
 
} // namespace numeric