sol2/sol/stack_probe.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
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#ifndef SOL_STACK_PROBE_HPP
#define SOL_STACK_PROBE_HPP

#include "stack_core.hpp"
#include "stack_field.hpp"
#include "stack_check.hpp"

namespace sol {
namespace stack {
template <typename T, bool b, typename>
struct probe_field_getter {
    template <typename Key>
    probe get(lua_State* L, Key&& key, int tableindex = -2) {
        get_field<b>(L, std::forward<Key>(key), tableindex);
	   return probe(!check<nil_t>(L), 1);
    }
};

template <typename... Args, bool b, typename C>
struct probe_field_getter<std::tuple<Args...>, b, C> {
    template <std::size_t I, typename Keys>
    probe apply(std::index_sequence<I>, int sofar, lua_State* L, Keys&& keys, int tableindex) {
        get_field<I < 1 && b>(L, std::get<I>(keys), tableindex);
        return probe(!check<nil_t>(L), sofar);
    }

    template <std::size_t I, std::size_t I1, std::size_t... In, typename Keys>
    probe apply(std::index_sequence<I, I1, In...>, int sofar, lua_State* L, Keys&& keys, int tableindex) {
        get_field<I < 1 && b>(L, std::get<I>(keys), tableindex);
        if (!maybe_indexable(L)) {
            return probe(false, sofar);
        }
        return apply(std::index_sequence<I1, In...>(), sofar + 1, L, std::forward<Keys>(keys), tableindex);
    }

    template <typename Keys>
    probe get(lua_State* L, Keys&& keys, int tableindex = -2) {
        return apply(std::index_sequence_for<Args...>(), 1, L, std::forward<Keys>(keys), tableindex);
    }
};
} // stack
} // sol

#endif // SOL_STACK_PROBE_HPP