merge.hpp

Go to the documentation of this file.

// SPDX-License-Identifier: BSL-1.0
// SPDX-FileCopyrightText: Copyright (C) 2019 Tobias Hienzsch
 
#ifndef TETL_ALGORITHM_MERGE_HPP
#define TETL_ALGORITHM_MERGE_HPP
 
#include <etl/_algorithm/copy.hpp>
#include <etl/_functional/less.hpp>
 
namespace etl {
 
/// \brief Merges two sorted ranges `[first1, last1)` and `[first2, last2)` into
/// one sorted range beginning at `destination`.
/// \ingroup algorithm
template <typename InputIt1, typename InputIt2, typename OutputIt, typename Compare>
constexpr auto
merge(InputIt1 first1, InputIt1 last1, InputIt2 first2, InputIt2 last2, OutputIt destination, Compare comp) -> OutputIt
{
    for (; first1 != last1; ++destination) {
        if (first2 == last2) {
            return etl::copy(first1, last1, destination);
        }
        if (comp(*first2, *first1)) {
            *destination = *first2;
            ++first2;
        } else {
            *destination = *first1;
            ++first1;
        }
    }
    return etl::copy(first2, last2, destination);
}
 
/// \ingroup algorithm
template <typename InputIt1, typename InputIt2, typename OutputIt>
constexpr auto merge(InputIt1 first1, InputIt1 last1, InputIt2 first2, InputIt2 last2, OutputIt destination) -> OutputIt
{
    return etl::merge(first1, last1, first2, last2, destination, etl::less());
}
 
} // namespace etl
 
#endif // TETL_ALGORITHM_MERGE_HPP