/**
	This file is a part of rexy's general purpose library
	Copyright (C) 2020 rexy712

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef REXY_TRAITS_HPP
#define REXY_TRAITS_HPP

#include <type_traits> //is_same, decay, integral_constant, declval

namespace rexy{

	template<class T, class U>
	struct is_type{
		static std::true_type check(U*);
		static std::false_type check(...);

		static constexpr bool value = std::is_same<std::true_type,decltype(check(std::declval<std::decay_t<T>*>()))>::value;
	};

	template<class T, template<class...> class U>
	struct is_template_type_helper{
		static constexpr bool value = false;
	};
	template<template<class...> class U, class... Args>
	struct is_template_type_helper<U<Args...>,U>{
		static constexpr bool value = true;
	};
	template<class T, template<class...> class U>
	struct is_template_type : public is_template_type_helper<std::decay_t<T>,U>{};

	template<class T, template<class...> class Tmpl>
	struct is_template_derived_type{
		template<class... Args>
		static std::true_type test(Tmpl<Args...>*);
		static std::false_type test(void*);

		static constexpr bool value = std::is_same<std::true_type,decltype(test(static_cast<std::decay_t<T>*>(nullptr)))>::value;
	};


}

#endif