transform.inl

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/**
 
    @file      transform.inl
    @author    Khrapov
    @date      1.10.2023
    @copyright © Nick Khrapov, 2023. All right reserved.
 
**/
 
namespace qx
{
 
namespace details
{
 
template<class T>
concept has_reserve_func = requires(T t) {
    { t.reserve(size_t()) };
};
 
template<class T>
concept has_size_func = requires(T t) {
    { t.size() } -> std::convertible_to<size_t>;
};
 
} // namespace details
 
template<
    template<class...> class result_container_t,
    class input_container_t,
    class transform_callable_t,
    class... result_container_rest_t>
auto transform_return(input_container_t&& input, const transform_callable_t& transformCallable)
{
    using result_type             = decltype(transformCallable(*input.begin()));
    using result_container_full_t = result_container_t<result_type, result_container_rest_t...>;
    result_container_full_t result;
 
    if constexpr (details::has_reserve_func<result_container_full_t> && details::has_size_func<input_container_t>)
        result.reserve(input.size());
 
    for (auto&& inputElement : input)
        result.insert(result.end(), transformCallable(std::forward<decltype(inputElement)>(inputElement)));
 
    return result;
}
 
} // namespace qx