slice.hpp

Go to the documentation of this file.

/*
 * Copyright 2018-2020, Intel Corporation
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *
 *     * Neither the name of the copyright holder nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
#ifndef LIBPMEMOBJ_CPP_SLICE_HPP
#define LIBPMEMOBJ_CPP_SLICE_HPP
 
#include <iterator>
#include <stdexcept>
#include <type_traits>
 
namespace pmem
{
 
namespace obj
{
 
template <typename Iterator>
class slice {
public:
    using size_type = std::size_t;
    using iterator = Iterator;
    using reverse_iterator = std::reverse_iterator<iterator>;
    using reference = typename std::iterator_traits<iterator>::reference;
 
    slice(Iterator begin, Iterator end) : it_begin(begin), it_end(end)
    {
        static_assert(
            std::is_same<typename std::iterator_traits<
                         iterator>::iterator_category,
                     std::random_access_iterator_tag>::value,
            "Iterator should have RandomAccessIterator tag");
 
        if (it_end < it_begin)
            throw std::out_of_range("pmem::obj::slice");
    }
 
    slice(const slice &other) noexcept = default;
 
    slice &operator=(const slice &other) noexcept = default;
 
    iterator
    begin() const noexcept
    {
        return it_begin;
    }
 
    iterator
    end() const noexcept
    {
        return it_end;
    }
 
    reverse_iterator
    rend() const noexcept
    {
        return reverse_iterator(it_begin);
    }
 
    reverse_iterator
    rbegin() const noexcept
    {
        return reverse_iterator(it_end);
    }
 
    reference
    at(size_type idx)
    {
        if (idx >= size())
            throw std::out_of_range("pmem::obj::slice");
 
        return it_begin[static_cast<typename std::iterator_traits<
            Iterator>::difference_type>(idx)];
    }
 
    reference operator[](size_type idx)
    {
        return it_begin[static_cast<typename std::iterator_traits<
            Iterator>::difference_type>(idx)];
    }
 
    size_type
    size() const
    {
        return static_cast<size_type>(it_end - it_begin);
    }
 
private:
    iterator it_begin, it_end;
};
 
} /* namespace obj */
 
} /* namespace pmem */
 
#endif /* LIBPMEMOBJ_CPP_SLICE_HPP */