number_of_one_bits.h

// Description: Number of one bits
// Documentation: bit_tricks.txt

#ifndef PASTELSYS_NUMBER_OF_ONE_BITS_H
#define PASTELSYS_NUMBER_OF_ONE_BITS_H

#include "pastel/sys/mytypes.h"
#include <limits.h>

namespace Pastel
{

    namespace NumberOfOneBits_
    {

        template <typename Type, int N>
        struct IsUnsigned
        {
        public:
            static constexpr bool value =
                std::is_unsigned<Type>::value &&
                (sizeof(Type) * CHAR_BIT) == N;
        };

    }

    //! Returns the number of 1-bits in a 64-bit unsigned integer.
    /*!
   Time complexity: O(1)
   Exception safety: nothrow
   */
    template <typename Type>
    requires NumberOfOneBits_::IsUnsigned<Type, 64>::value
    integer numberOfOneBits(Type that);

    //! Returns the number of 1-bits in a 32-bit unsigned integer.
    /*!
   Time complexity: O(1)
   Exception safety: nothrow
   */
    template <typename Type>
    requires NumberOfOneBits_::IsUnsigned<Type, 32>::value
    integer numberOfOneBits(Type that);

    //! Returns the number of 1-bits in a 16-bit unsigned integer.
    /*!
   Time complexity: O(1)
   Exception safety: nothrow
   */
    template <typename Type>
    requires NumberOfOneBits_::IsUnsigned<Type, 16>::value
    integer numberOfOneBits(Type that);

    //! Returns the number of 1-bits in an 8-bit unsigned integer.
    /*!
   Time complexity: O(1)
   Exception safety: nothrow
   */
    template <typename Type>
    requires NumberOfOneBits_::IsUnsigned<Type, 8>::value
    integer numberOfOneBits(Type that);

}

#include "pastel/sys/bit/number_of_one_bits.hpp"

#endif