6fbfad6b00
<https://cplusplus.github.io/LWG/issue3320> "span::cbegin/cend methods produce different results than std::[ranges::]cbegin/cend", as implemented now in <https://gcc.gnu.org/git/gitweb.cgi?p=gcc.git;a=commit; h=247f410b83797a1840573840cc2a539ef9d7f96b> "libstdc++: Remove std::span::cbegin and std::span::cend (LWG 3320)". Turns out we only used the removed member functions in o3tl/qa/test-span.cxx. Change-Id: I6c73797594b4e0e753a88840033d54961e271df5 Reviewed-on: https://gerrit.libreoffice.org/c/core/+/89261 Tested-by: Jenkins Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
90 lines
2.3 KiB
C++
90 lines
2.3 KiB
C++
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
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/*
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* This file is part of the LibreOffice project.
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*
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/.
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*/
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#ifndef INCLUDED_O3TL_SPAN_HXX
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#define INCLUDED_O3TL_SPAN_HXX
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#include <sal/config.h>
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#include <config_global.h>
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#if HAVE_CPP_SPAN
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#include <span>
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namespace o3tl { using std::span; }
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#else
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#include <cassert>
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#include <cstddef>
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#include <iterator>
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namespace o3tl {
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/** A barebones approximation of C++20 <span>.
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*/
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template<typename T>
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class span {
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public:
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using value_type = T;
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using pointer = value_type *;
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using const_pointer = value_type const *;
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using reference = value_type &;
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using const_reference = value_type const &;
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using const_iterator = const_pointer;
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using iterator = pointer;
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using const_reverse_iterator = std::reverse_iterator<const_iterator>;
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using reverse_iterator = std::reverse_iterator<iterator>;
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using size_type = std::size_t;
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using difference_type = std::ptrdiff_t;
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constexpr span() noexcept : data_(nullptr), size_(0) {}
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template<std::size_t N>
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constexpr span (T (&a)[N]) noexcept : data_(a), size_(N) {}
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constexpr span (T *a, size_type len) noexcept
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: data_(a), size_(len)
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{
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// not terribly sure about this, might need to strengthen it
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assert(a != nullptr || len == 0);
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}
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constexpr bool empty() const noexcept { return size_ == 0; }
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constexpr iterator begin() const noexcept { return data_; }
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constexpr iterator end() const noexcept { return begin() + size(); }
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reverse_iterator rbegin() const noexcept
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{ return reverse_iterator(end()); }
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reverse_iterator rend() const noexcept
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{ return reverse_iterator(begin()); }
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constexpr size_type size() const noexcept { return size_; }
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constexpr reference operator [](size_type pos) const {
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assert(pos < size());
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return data_[pos];
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}
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constexpr pointer data() const noexcept { return data_; }
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private:
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pointer data_;
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size_type size_;
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};
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} // namespace o3tl
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#endif
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#endif
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/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */
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