unique_copy.hpp

Go to the documentation of this file.

// SPDX-License-Identifier: BSL-1.0
// SPDX-FileCopyrightText: Copyright (C) 2019 Tobias Hienzsch
 
#ifndef TETL_ALGORITHM_UNIQUE_COPY_HPP
#define TETL_ALGORITHM_UNIQUE_COPY_HPP
 
#include <etl/_functional/equal_to.hpp>
 
namespace etl {
 
/// \ingroup algorithm
/// @{
 
/// Copies the elements from the range `[first, last)`, to another range
/// beginning at d_first in such a way that there are no consecutive equal
/// elements. Only the first element of each group of equal elements is copied.
///
/// Elements are compared using the given binary predicate pred. The behavior
/// is undefined if it is not an equivalence relation.
template <typename InputIt, typename OutputIt, typename Predicate>
constexpr auto unique_copy(InputIt first, InputIt last, OutputIt destination, Predicate pred) -> OutputIt
{
    if (first != last) {
        *destination = *first;
 
        while (++first != last) {
            if (not pred(*destination, *first)) {
                *++destination = *first;
            }
        }
 
        ++destination;
    }
 
    return destination;
}
 
template <typename InputIt, typename OutputIt>
constexpr auto unique_copy(InputIt first, InputIt last, OutputIt destination) -> OutputIt
{
    return etl::unique_copy(first, last, destination, etl::equal_to());
}
 
/// @}
 
} // namespace etl
 
#endif // TETL_ALGORITHM_UNIQUE_COPY_HPP