from_rep.h

 
//          Copyright John McFarlane 2018.
// Distributed under the Boost Software License, Version 1.0.
//    (See accompanying file ../LICENSE_1_0.txt or copy at
//          http://www.boost.org/LICENSE_1_0.txt)
 
#if !defined(CNL_IMPL_NUM_TRAITS_FROM_REP_H)
#define CNL_IMPL_NUM_TRAITS_FROM_REP_H
 
#include <concepts>
 
namespace cnl {
    template<typename Number, typename Rep>
    struct from_rep;
 
    template<std::integral Number, typename Rep>
    struct from_rep<Number, Rep> {
        [[nodiscard]] constexpr auto operator()(Rep const& rep) const
        {
            // by default, a number type's rep type is the number type itself
            return static_cast<Number>(rep);
        }
    };
 
    namespace _impl {
        template<class Number, class Rep>
        [[nodiscard]] constexpr auto from_rep(Rep const& rep)
        {
            return cnl::from_rep<Number, Rep>{}(rep);
        }
    }
}
 
#endif  // CNL_IMPL_NUM_TRAITS_FROM_REP_H