sol2/sol/object.hpp

// The MIT License (MIT) 

// Copyright (c) 2013-2017 Rapptz, ThePhD and contributors

// Permission is hereby granted, free of charge, to any person obtaining a copy of
// this software and associated documentation files (the "Software"), to deal in
// the Software without restriction, including without limitation the rights to
// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
// the Software, and to permit persons to whom the Software is furnished to do so,
// subject to the following conditions:

// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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#ifndef SOL_OBJECT_HPP
#define SOL_OBJECT_HPP

#include "reference.hpp"
#include "stack.hpp"
#include "object_base.hpp"
#include "userdata.hpp"
#include "as_args.hpp"
#include "variadic_args.hpp"
#include "optional.hpp"

namespace sol {

	template <typename R = reference, bool should_pop = !std::is_base_of<stack_reference, R>::value, typename T>
	R make_reference(lua_State* L, T&& value) {
		int backpedal = stack::push(L, std::forward<T>(value));
		R r = stack::get<R>(L, -backpedal);
		if (should_pop) {
			lua_pop(L, backpedal);
		}
		return r;
	}

	template <typename T, typename R = reference, bool should_pop = !std::is_base_of<stack_reference, R>::value, typename... Args>
	R make_reference(lua_State* L, Args&&... args) {
		int backpedal = stack::push<T>(L, std::forward<Args>(args)...);
		R r = stack::get<R>(L, -backpedal);
		if (should_pop) {
			lua_pop(L, backpedal);
		}
		return r;
	}

	template <typename base_type>
	class basic_object : public basic_object_base<base_type> {
	private:
		typedef basic_object_base<base_type> base_t;

		template <bool invert_and_pop = false>
		basic_object(std::integral_constant<bool, invert_and_pop>, lua_State* L, int index = -1) noexcept : base_t(L, index) {
			if (invert_and_pop) {
				lua_pop(L, -index);
			}
		}

	public:
		basic_object() noexcept = default;
		template <typename T, meta::enable<meta::neg<std::is_same<meta::unqualified_t<T>, basic_object>>, meta::neg<std::is_same<base_type, stack_reference>>, std::is_base_of<base_type, meta::unqualified_t<T>>> = meta::enabler>
		basic_object(T&& r) : base_t(std::forward<T>(r)) {}
		basic_object(lua_nil_t r) : base_t(r) {}
		basic_object(const basic_object&) = default;
		basic_object(basic_object&&) = default;
		basic_object(const stack_reference& r) noexcept : basic_object(r.lua_state(), r.stack_index()) {}
		basic_object(stack_reference&& r) noexcept : basic_object(r.lua_state(), r.stack_index()) {}
		template <typename Super>
		basic_object(const proxy_base<Super>& r) noexcept : basic_object(r.operator basic_object()) {}
		template <typename Super>
		basic_object(proxy_base<Super>&& r) noexcept : basic_object(r.operator basic_object()) {}
		basic_object(lua_State* L, int index = -1) noexcept : base_t(L, index) {}
		basic_object(lua_State* L, ref_index index) noexcept : base_t(L, index) {}
		template <typename T, typename... Args>
		basic_object(lua_State* L, in_place_type_t<T>, Args&&... args) noexcept 
		: basic_object(std::integral_constant<bool, !std::is_base_of<stack_reference, base_t>::value>(), L, -stack::push<T>(L, std::forward<Args>(args)...)) {}
		template <typename T, typename... Args>
		basic_object(lua_State* L, in_place_t, T&& arg, Args&&... args) noexcept 
		: basic_object(L, in_place_type<T>, std::forward<T>(arg), std::forward<Args>(args)...) {}
		basic_object& operator=(const basic_object&) = default;
		basic_object& operator=(basic_object&&) = default;
		basic_object& operator=(const base_type& b) { base_t::operator=(b); return *this; }
		basic_object& operator=(base_type&& b) { base_t::operator=(std::move(b)); return *this; }
		template <typename Super>
		basic_object& operator=(const proxy_base<Super>& r) { this->operator=(r.operator basic_object()); return *this; }
		template <typename Super>
		basic_object& operator=(proxy_base<Super>&& r) { this->operator=(r.operator basic_object()); return *this; }
	};

	template <typename T>
	object make_object(lua_State* L, T&& value) {
		return make_reference<object, true>(L, std::forward<T>(value));
	}

	template <typename T, typename... Args>
	object make_object(lua_State* L, Args&&... args) {
		return make_reference<T, object, true>(L, std::forward<Args>(args)...);
	}
} // sol

#endif // SOL_OBJECT_HPP