sol2/include/sol/function.hpp

// sol3 

// The MIT License (MIT)

// Copyright (c) 2013-2019 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
// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

#ifndef SOL_FUNCTION_HPP
#define SOL_FUNCTION_HPP

#include "stack.hpp"
#include "unsafe_function.hpp"
#include "protected_function.hpp"
#include <functional>

namespace sol {
	template <typename... Ret, typename... Args>
	inline decltype(auto) stack_proxy::call(Args&&... args) {
		stack_function sf(this->lua_state(), this->stack_index());
		return sf.template call<Ret...>(std::forward<Args>(args)...);
	}

	inline protected_function_result::protected_function_result(unsafe_function_result&& o) noexcept
	: L(o.lua_state()), index(o.stack_index()), returncount(o.return_count()), popcount(o.return_count()), err(o.status()) {
		// Must be manual, otherwise destructor will screw us
		// return count being 0 is enough to keep things clean
		// but we will be thorough
		o.abandon();
	}

	inline protected_function_result& protected_function_result::operator=(unsafe_function_result&& o) noexcept {
		L = o.lua_state();
		index = o.stack_index();
		returncount = o.return_count();
		popcount = o.return_count();
		err = o.status();
		// Must be manual, otherwise destructor will screw us
		// return count being 0 is enough to keep things clean
		// but we will be thorough
		o.abandon();
		return *this;
	}

	inline unsafe_function_result::unsafe_function_result(protected_function_result&& o) noexcept
	: L(o.lua_state()), index(o.stack_index()), returncount(o.return_count()) {
		// Must be manual, otherwise destructor will screw us
		// return count being 0 is enough to keep things clean
		// but we will be thorough
		o.abandon();
	}
	inline unsafe_function_result& unsafe_function_result::operator=(protected_function_result&& o) noexcept {
		L = o.lua_state();
		index = o.stack_index();
		returncount = o.return_count();
		// Must be manual, otherwise destructor will screw us
		// return count being 0 is enough to keep things clean
		// but we will be thorough
		o.abandon();
		return *this;
	}

	namespace detail {
		template <typename... R>
		struct std_shim {
			unsafe_function lua_func_;

			std_shim(unsafe_function lua_func) : lua_func_(std::move(lua_func)) {
			}

			template <typename... Args>
			meta::return_type_t<R...> operator()(Args&&... args) {
				return lua_func_.call<R...>(std::forward<Args>(args)...);
			}
		};

		template <>
		struct std_shim<void> {
			unsafe_function lua_func_;

			std_shim(unsafe_function lua_func) : lua_func_(std::move(lua_func)) {
			}

			template <typename... Args>
			void operator()(Args&&... args) {
				lua_func_.call<void>(std::forward<Args>(args)...);
			}
		};
	} // namespace detail

	namespace stack {
		template <typename Signature>
		struct unqualified_getter<std::function<Signature>> {
			typedef meta::bind_traits<Signature> fx_t;
			typedef typename fx_t::args_list args_lists;
			typedef meta::tuple_types<typename fx_t::return_type> return_types;

			template <typename... R>
			static std::function<Signature> get_std_func(types<R...>, lua_State* L, int index) {
				detail::std_shim<R...> fx(unsafe_function(L, index));
				return std::move(fx);
			}

			static std::function<Signature> get(lua_State* L, int index, record& tracking) {
				tracking.last = 1;
				tracking.used += 1;
				type t = type_of(L, index);
				if (t == type::none || t == type::lua_nil) {
					return nullptr;
				}
				return get_std_func(return_types(), L, index);
			}
		};
	} // namespace stack

} // namespace sol

#endif // SOL_FUNCTION_HPP