sol2/sol/load_result.hpp

// The MIT License (MIT) 

// Copyright (c) 2013-2016 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_LOAD_RESULT_HPP
#define SOL_LOAD_RESULT_HPP

#include "stack.hpp"
#include "function.hpp"
#include "proxy_base.hpp"
#include <cstdint>

namespace sol {
	struct load_result : public proxy_base<load_result> {
	private:
		lua_State* L;
		int index;
		int returncount;
		int popcount;
		load_status err;

		template <typename T>
		decltype(auto) tagged_get(types<sol::optional<T>>) const {
			if (!valid()) {
				return sol::optional<T>(nullopt);
			}
			return stack::get<sol::optional<T>>(L, index);
		}

		template <typename T>
		decltype(auto) tagged_get(types<T>) const {
#ifdef SOL_CHECK_ARGUMENTS
			if (!valid()) {
				type_panic(L, index, type_of(L, index), type::none);
			}
#endif // Check Argument Safety
			return stack::get<T>(L, index);
		}

		sol::optional<sol::error> tagged_get(types<sol::optional<sol::error>>) const {
			if (valid()) {
				return nullopt;
			}
			return sol::error(detail::direct_error, stack::get<std::string>(L, index));
		}

		sol::error tagged_get(types<sol::error>) const {
#ifdef SOL_CHECK_ARGUMENTS
			if (valid()) {
				type_panic(L, index, type_of(L, index), type::none);
			}
#endif // Check Argument Safety
			return sol::error(detail::direct_error, stack::get<std::string>(L, index));
		}

	public:
		load_result() = default;
		load_result(lua_State* L, int index = -1, int returncount = 0, int popcount = 0, load_status err = load_status::ok) : L(L), index(index), returncount(returncount), popcount(popcount), err(err) {

		}
		load_result(const load_result&) = default;
		load_result& operator=(const load_result&) = default;
		load_result(load_result&& o) : L(o.L), index(o.index), returncount(o.returncount), popcount(o.popcount), err(o.err) {
			// Must be manual, otherwise destructor will screw us
			// return count being 0 is enough to keep things clean
			// but will be thorough
			o.L = nullptr;
			o.index = 0;
			o.returncount = 0;
			o.popcount = 0;
			o.err = load_status::syntax;
		}
		load_result& operator=(load_result&& o) {
			L = o.L;
			index = o.index;
			returncount = o.returncount;
			popcount = o.popcount;
			err = o.err;
			// Must be manual, otherwise destructor will screw us
			// return count being 0 is enough to keep things clean
			// but will be thorough
			o.L = nullptr;
			o.index = 0;
			o.returncount = 0;
			o.popcount = 0;
			o.err = load_status::syntax;
			return *this;
		}

		load_status error() const {
			return err;
		}

		bool valid() const {
			return error() == load_status::ok;
		}

		template<typename T>
		T get() const {
			return tagged_get(types<meta::Unqualified<T>>());
		}

		template<typename... Ret, typename... Args>
		decltype(auto) call(Args&&... args) {
			return get<function>().template call<Ret...>(std::forward<Args>(args)...);
		}

		template<typename... Args>
		decltype(auto) operator()(Args&&... args) {
			return call<>(std::forward<Args>(args)...);
		}

		lua_State* lua_state() const { return L; };
		int stack_index() const { return index; };

		~load_result() {
			stack::remove(L, index, popcount);
		}
	};
} // sol

#endif // SOL_LOAD_RESULT_HPP