multi_integer_concepts.h

// Description: Concepts for multi-integer

#ifndef PASTELSYS_MULTI_INTEGER_CONCEPTS_H
#define PASTELSYS_MULTI_INTEGER_CONCEPTS_H

#include "pastel/sys/integer/multi_integer.h"
#include "pastel/sys/integer/integer_concept.h"

namespace Pastel
{

    struct MultiInteger_Settings_Concept
    {
        template <typename Type>
        auto requires_(Type&& t) -> decltype
        (
            conceptCheck(
                //! The number of bits in the integer.
                Concept::convertsTo<integer>(Type::N),

                //! The type of the underlying word.
                /*!
               A double-word type integer is required to exist,
               so that multiplication of two words can be stored.

               Choosing this type other than uinteger_half is mainly 
               useful for testing the correctness of the 
               implementation, although for small bit-counts 
               one may also choose to minimize the wasted space 
               by choosing the basic type smaller.
               */
                Concept::holds<std::is_unsigned<typename Type::Word>>(),
                Concept::exists<UIntegerOfSize<2 * SizeInBits<typename Type::Word>::value>>(),

                //! Whether to interpret as a signed integer.
                /*!
               If Signed is true, then the integer is interpreted
               as a signed integer in two's complement form.
               If Signed is false, then the integer is interpreted
               as an unsigned integer, so that it's always
               positive, and the arithmetic works modulo 2^N,
               except for the division.
               */
                Concept::convertsTo<bool>(Type::Signed)
            )
        );
    };

    struct MultiInteger_Settings_Archetype
    {
        static constexpr integer N = 2;
        using Word = uint32;
        static constexpr bool Signed = true;
    };

    PASTEL_CONCEPT_CHECK(MultiInteger_Settings_Archetype, MultiInteger_Settings_Concept);

}

#endif