sol2/sol/stack_check_get.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_STACK_CHECK_GET_HPP
#define SOL_STACK_CHECK_GET_HPP

#include "stack_core.hpp"
#include "stack_get.hpp"
#include "stack_check.hpp"
#include "optional.hpp"

namespace sol {
	namespace stack {
		template <typename T, typename>
		struct check_getter {
			typedef stack_detail::strip_t<T> U;
			typedef std::conditional_t<is_proxy_primitive<T>::value, U, U&> R;

			template <typename Handler>
			static optional<R> get(lua_State* L, int index, Handler&& handler) {
				if (!check<T>(L, index, std::forward<Handler>(handler)))
					return nullopt;
				return stack_detail::unchecked_get<T>(L, index);
			}
		};

		template <typename T>
		struct check_getter<optional<T>> {
			template <typename Handler>
			static decltype(auto) get(lua_State* L, int index, Handler&&) {
				return check_get<T>(L, index, no_panic);
			}
		};

		template <typename T>
		struct check_getter<T, std::enable_if_t<std::is_integral<T>::value && lua_type_of<T>::value == type::number>> {
			template <typename Handler>
			static optional<T> get(lua_State* L, int index, Handler&& handler) {
				int isnum = 0;
				lua_Integer value = lua_tointegerx(L, index, &isnum);
				if (isnum == 0) {
					handler(L, index, type::number, type_of(L, index));
					return nullopt;
				}
				return static_cast<T>(value);
			}
		};

		template <typename T>
		struct check_getter<T, std::enable_if_t<std::is_enum<T>::value && !meta::any_same<T, meta_function, type>::value>> {
			template <typename Handler>
			static optional<T> get(lua_State* L, int index, Handler&& handler) {
				int isnum = 0;
				lua_Integer value = lua_tointegerx(L, index, &isnum);
				if (isnum == 0) {
					handler(L, index, type::number, type_of(L, index));
					return nullopt;
				}
				return static_cast<T>(value);
			}
		};

		template <typename T>
		struct check_getter<T, std::enable_if_t<std::is_floating_point<T>::value>> {
			template <typename Handler>
			static optional<T> get(lua_State* L, int index, Handler&& handler) {
				int isnum = 0;
				lua_Number value = lua_tonumberx(L, index, &isnum);
				if (isnum == 0) {
					handler(L, index, type::number, type_of(L, index));
					return nullopt;
				}
				return static_cast<T>(value);
			}
		};

		template <typename T>
		struct getter<optional<T>> {
			static decltype(auto) get(lua_State* L, int index) {
				return check_get<T>(L, index, no_panic);
			}
		};
	} // stack
} // sol

#endif // SOL_STACK_CHECK_GET_HPP