sol2/sol/object.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_OBJECT_HPP
#define SOL_OBJECT_HPP

#include "reference.hpp"
#include "userdata.hpp"
#include "stack.hpp"

namespace sol {
template <typename base_t>
class basic_object : public base_t {
private:
    template<typename T>
    decltype(auto) as_stack(std::true_type) const {
        return stack::get<T>(lua_state(), base_t::stack_index());
    }

    template<typename T>
    decltype(auto) as_stack(std::false_type) const {
        base_t::push();
        return stack::pop<T>(lua_state());
    }

    template<typename T>
    bool is_stack(std::true_type) const {
        return stack::check<T>(lua_state(), base_t::stack_index(), no_panic);
    }

    template<typename T>
    bool is_stack(std::false_type) const {
        auto pp = stack::push_pop(*this);
        return stack::check<T>(lua_state(), -1, no_panic);
    }

public:
    using base_t::base_t;
    using base_t::lua_state;

    template<typename T>
    decltype(auto) as() const {
        return as_stack<T>( std::is_same<base_t, stack_reference>() );
    }

    template<typename T>
    bool is() const {
        if (!base_t::valid())
            return false;
        return is_stack<T>(std::is_same<base_t, stack_reference>());
    }
};

inline bool operator==(const object& lhs, const nil_t&) {
    return !lhs.valid();
}

inline bool operator==(const nil_t&, const object& rhs) {
    return !rhs.valid();
}

inline bool operator!=(const object& lhs, const nil_t&) {
    return lhs.valid();
}

inline bool operator!=(const nil_t&, const object& rhs) {
    return rhs.valid();
}
} // sol

#endif // SOL_OBJECT_HPP