sol2/sol/function_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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// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

#ifndef SOL_FUNCTION_RESULT_HPP
#define SOL_FUNCTION_RESULT_HPP

#include "reference.hpp"
#include "tuple.hpp"
#include "stack.hpp"
#include "stack_proxy.hpp"
#include "proxy_base.hpp"
#include <cstdint>

namespace sol {
struct function_result : public proxy_base<function_result> {
private:
    lua_State* L;
    int index;
    int returncount;

public:
    function_result() = default;
    function_result(lua_State* L, int index = -1, int returncount = 0): L(L), index(index), returncount(returncount) {
        
    }
    function_result(const function_result&) = default;
    function_result& operator=(const function_result&) = default;
    function_result(function_result&& o) : L(o.L), index(o.index), returncount(o.returncount) {
        // 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;
    }
    function_result& operator=(function_result&& o) {
        L = o.L;
        index = o.index;
        returncount = o.returncount;
        // 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;
        return *this;
    }

    template<typename T>
    decltype(auto) get() const {
        return stack::get<T>(L, index);
    }

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

    ~function_result() {
        lua_pop(L, returncount);
    }
};

template <>
struct bond_size<function_result> : std::integral_constant<std::size_t, SIZE_MAX> {};

template <std::size_t I>
stack_proxy get(const function_result& fr) {
    return stack_proxy(fr.lua_state(), static_cast<int>(fr.stack_index() + I));
}
} // sol

#endif // SOL_FUNCTION_RESULT_HPP