OpenTTD/src/core/container_func.hpp

50 lines
2.0 KiB
C++

/*
* This file is part of OpenTTD.
* OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
* OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
*/
/** @file container_func.hpp Some simple functions to help with accessing containers. */
#ifndef CONTAINER_FUNC_HPP
#define CONTAINER_FUNC_HPP
/**
* Helper function to append an item to a container if it is not already contained.
* The container must have a \c emplace_back function.
* Consider using std::set, std::unordered_set or std::flat_set in new code.
*
* @param container A reference to the container to be extended
* @param item Reference to the item to be copy-constructed if not found
*
* @return Whether the item was already present
*/
template <typename Container>
inline bool include(Container &container, typename Container::const_reference &item)
{
const bool is_member = std::find(container.begin(), container.end(), item) != container.end();
if (!is_member) container.emplace_back(item);
return is_member;
}
/**
* Helper function to get the index of an item
* Consider using std::set, std::unordered_set or std::flat_set in new code.
*
* @param container A reference to the container to be searched.
* @param item Reference to the item to be search for
*
* @return Index of element if found, otherwise -1
*/
template <typename Container>
int find_index(Container const &container, typename Container::const_reference item)
{
auto const it = std::find(container.begin(), container.end(), item);
if (it != container.end()) return std::distance(container.begin(), it);
return -1;
}
#endif /* CONTAINER_FUNC_HPP */