sol2/include/sol/stack_field.hpp

// sol3

// The MIT License (MIT)

// Copyright (c) 2013-2018 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_STACK_FIELD_HPP
#define SOL_STACK_FIELD_HPP

#include "stack_core.hpp"
#include "stack_push.hpp"
#include "stack_get.hpp"
#include "stack_check_get.hpp"

namespace sol {
namespace stack {
	template <typename T, bool, bool, typename>
	struct field_getter {
		template <typename Key>
		void get(lua_State* L, Key&& key, int tableindex = -2) {
			push(L, std::forward<Key>(key));
			lua_gettable(L, tableindex);
		}
	};

	template <typename T, bool global, typename C>
	struct field_getter<T, global, true, C> {
		template <typename Key>
		void get(lua_State* L, Key&& key, int tableindex = -2) {
			push(L, std::forward<Key>(key));
			lua_rawget(L, tableindex);
		}
	};

	template <bool b, bool raw, typename C>
	struct field_getter<metatable_t, b, raw, C> {
		void get(lua_State* L, metatable_t, int tableindex = -1) {
			if (lua_getmetatable(L, tableindex) == 0)
				push(L, lua_nil);
		}
	};

	template <bool b, bool raw, typename C>
	struct field_getter<env_t, b, raw, C> {
		void get(lua_State* L, env_t, int tableindex = -1) {
#if SOL_LUA_VERSION < 502
			// Use lua_setfenv
			lua_getfenv(L, tableindex);
#else
			// Use upvalues as explained in Lua 5.2 and beyond's manual
			if (lua_getupvalue(L, tableindex, 1) == nullptr) {
				push(L, lua_nil);
			}
#endif
		}
	};

	template <typename T, bool raw>
	struct field_getter<T, true, raw, std::enable_if_t<meta::is_c_str<T>::value>> {
		template <typename Key>
		void get(lua_State* L, Key&& key, int = -1) {
			lua_getglobal(L, &key[0]);
		}
	};

	template <typename T>
	struct field_getter<T, false, false, std::enable_if_t<meta::is_c_str<T>::value>> {
		template <typename Key>
		void get(lua_State* L, Key&& key, int tableindex = -1) {
			lua_getfield(L, tableindex, &key[0]);
		}
	};

#if SOL_LUA_VERSION >= 503
	template <typename T>
	struct field_getter<T, false, false, std::enable_if_t<std::is_integral<T>::value && !std::is_same<bool, T>::value>> {
		template <typename Key>
		void get(lua_State* L, Key&& key, int tableindex = -1) {
			lua_geti(L, tableindex, static_cast<lua_Integer>(key));
		}
	};
#endif // Lua 5.3.x

#if SOL_LUA_VERSION >= 502
	template <typename C>
	struct field_getter<void*, false, true, C> {
		void get(lua_State* L, void* key, int tableindex = -1) {
			lua_rawgetp(L, tableindex, key);
		}
	};
#endif // Lua 5.3.x

	template <typename T>
	struct field_getter<T, false, true, std::enable_if_t<std::is_integral<T>::value && !std::is_same<bool, T>::value>> {
		template <typename Key>
		void get(lua_State* L, Key&& key, int tableindex = -1) {
			lua_rawgeti(L, tableindex, static_cast<lua_Integer>(key));
		}
	};

	template <typename... Args, bool b, bool raw, typename C>
	struct field_getter<std::tuple<Args...>, b, raw, C> {
		template <std::size_t... I, typename Keys>
		void apply(std::index_sequence<0, I...>, lua_State* L, Keys&& keys, int tableindex) {
			get_field<b, raw>(L, std::get<0>(std::forward<Keys>(keys)), tableindex);
			void(detail::swallow { (get_field<false, raw>(L, std::get<I>(std::forward<Keys>(keys))), 0)... });
			reference saved(L, -1);
			lua_pop(L, static_cast<int>(sizeof...(I)));
			saved.push();
		}

		template <typename Keys>
		void get(lua_State* L, Keys&& keys) {
			apply(std::make_index_sequence<sizeof...(Args)>(), L, std::forward<Keys>(keys), lua_absindex(L, -1));
		}

		template <typename Keys>
		void get(lua_State* L, Keys&& keys, int tableindex) {
			apply(std::make_index_sequence<sizeof...(Args)>(), L, std::forward<Keys>(keys), tableindex);
		}
	};

	template <typename A, typename B, bool b, bool raw, typename C>
	struct field_getter<std::pair<A, B>, b, raw, C> {
		template <typename Keys>
		void get(lua_State* L, Keys&& keys, int tableindex) {
			get_field<b, raw>(L, std::get<0>(std::forward<Keys>(keys)), tableindex);
			get_field<false, raw>(L, std::get<1>(std::forward<Keys>(keys)));
			reference saved(L, -1);
			lua_pop(L, static_cast<int>(2));
			saved.push();
		}

		template <typename Keys>
		void get(lua_State* L, Keys&& keys) {
			get_field<b, raw>(L, std::get<0>(std::forward<Keys>(keys)));
			get_field<false, raw>(L, std::get<1>(std::forward<Keys>(keys)));
			reference saved(L, -1);
			lua_pop(L, static_cast<int>(2));
			saved.push();
		}
	};

	template <typename T, bool, bool, typename>
	struct field_setter {
		template <typename Key, typename Value>
		void set(lua_State* L, Key&& key, Value&& value, int tableindex = -3) {
			push(L, std::forward<Key>(key));
			push(L, std::forward<Value>(value));
			lua_settable(L, tableindex);
		}
	};

	template <typename T, bool b>
	struct field_setter<T, b, true, std::enable_if_t<!std::is_same<metatable_t, meta::unqualified_t<T>>::value>> {
		template <typename Key, typename Value>
		void set(lua_State* L, Key&& key, Value&& value, int tableindex = -3) {
			push(L, std::forward<Key>(key));
			push(L, std::forward<Value>(value));
			lua_rawset(L, tableindex);
		}
	};

	template <bool b, bool raw, typename C>
	struct field_setter<metatable_t, b, raw, C> {
		template <typename Value>
		void set(lua_State* L, metatable_t, Value&& value, int tableindex = -2) {
			push(L, std::forward<Value>(value));
			lua_setmetatable(L, tableindex);
		}
	};

	template <typename T, bool raw>
	struct field_setter<T, true, raw, std::enable_if_t<meta::is_c_str<T>::value>> {
		template <typename Key, typename Value>
		void set(lua_State* L, Key&& key, Value&& value, int = -2) {
			push(L, std::forward<Value>(value));
			lua_setglobal(L, &key[0]);
		}
	};

	template <typename T>
	struct field_setter<T, false, false, std::enable_if_t<meta::is_c_str<T>::value>> {
		template <typename Key, typename Value>
		void set(lua_State* L, Key&& key, Value&& value, int tableindex = -2) {
			push(L, std::forward<Value>(value));
			lua_setfield(L, tableindex, &key[0]);
		}
	};

#if SOL_LUA_VERSION >= 503
	template <typename T>
	struct field_setter<T, false, false, std::enable_if_t<std::is_integral<T>::value && !std::is_same<bool, T>::value>> {
		template <typename Key, typename Value>
		void set(lua_State* L, Key&& key, Value&& value, int tableindex = -2) {
			push(L, std::forward<Value>(value));
			lua_seti(L, tableindex, static_cast<lua_Integer>(key));
		}
	};
#endif // Lua 5.3.x

	template <typename T>
	struct field_setter<T, false, true, std::enable_if_t<std::is_integral<T>::value && !std::is_same<bool, T>::value>> {
		template <typename Key, typename Value>
		void set(lua_State* L, Key&& key, Value&& value, int tableindex = -2) {
			push(L, std::forward<Value>(value));
			lua_rawseti(L, tableindex, static_cast<lua_Integer>(key));
		}
	};

#if SOL_LUA_VERSION >= 502
	template <typename C>
	struct field_setter<void*, false, true, C> {
		template <typename Key, typename Value>
		void set(lua_State* L, void* key, Value&& value, int tableindex = -2) {
			push(L, std::forward<Value>(value));
			lua_rawsetp(L, tableindex, key);
		}
	};
#endif // Lua 5.2.x

	template <typename... Args, bool b, bool raw, typename C>
	struct field_setter<std::tuple<Args...>, b, raw, C> {
		template <bool g, std::size_t I, typename Keys, typename Value>
		void apply(std::index_sequence<I>, lua_State* L, Keys&& keys, Value&& value, int tableindex) {
			I < 1 ? set_field<g, raw>(L, std::get<I>(std::forward<Keys>(keys)), std::forward<Value>(value), tableindex)
				 : set_field<g, raw>(L, std::get<I>(std::forward<Keys>(keys)), std::forward<Value>(value));
		}

		template <bool g, std::size_t I0, std::size_t I1, std::size_t... I, typename Keys, typename Value>
		void apply(std::index_sequence<I0, I1, I...>, lua_State* L, Keys&& keys, Value&& value, int tableindex) {
			I0 < 1 ? get_field<g, raw>(L, std::get<I0>(std::forward<Keys>(keys)), tableindex)
				  : get_field<g, raw>(L, std::get<I0>(std::forward<Keys>(keys)), -1);
			apply<false>(std::index_sequence<I1, I...>(), L, std::forward<Keys>(keys), std::forward<Value>(value), -1);
		}

		template <bool g, std::size_t I0, std::size_t... I, typename Keys, typename Value>
		void top_apply(std::index_sequence<I0, I...>, lua_State* L, Keys&& keys, Value&& value, int tableindex) {
			apply<g>(std::index_sequence<I0, I...>(), L, std::forward<Keys>(keys), std::forward<Value>(value), tableindex);
			lua_pop(L, static_cast<int>(sizeof...(I)));
		}

		template <typename Keys, typename Value>
		void set(lua_State* L, Keys&& keys, Value&& value, int tableindex = -3) {
			top_apply<b>(std::make_index_sequence<sizeof...(Args)>(), L, std::forward<Keys>(keys), std::forward<Value>(value), tableindex);
		}
	};

	template <typename A, typename B, bool b, bool raw, typename C>
	struct field_setter<std::pair<A, B>, b, raw, C> {
		template <typename Keys, typename Value>
		void set(lua_State* L, Keys&& keys, Value&& value, int tableindex = -1) {
			get_field<b, raw>(L, std::get<0>(std::forward<Keys>(keys)), tableindex);
			set_field<false, raw>(L, std::get<1>(std::forward<Keys>(keys)), std::forward<Value>(value));
			lua_pop(L, 1);
		}
	};
}
} // namespace sol::stack

#endif // SOL_STACK_FIELD_HPP