is_subtractable.h

// Description: Tests whether a type has subtraction.

#ifndef PASTELSYS_IS_SUBTRACTABLE_H
#define PASTELSYS_IS_SUBTRACTABLE_H

#include "pastel/sys/type_traits.h"

namespace Pastel
{

        template <typename T>
        concept Is_Subtractable__ = requires(T t) {
            t - t;
        };

        template <typename T>
        concept Is_Subtractable_ = 
            Is_Subtractable__<RemoveCvRef<T>>;

        template <typename Type>
        using Is_Subtractable = 
            std::bool_constant<Is_Subtractable_<Type>>;

}

#endif