diff options
| -rw-r--r-- | libstdc++-v3/include/std/span | 12 | ||||
| -rw-r--r-- | libstdc++-v3/testsuite/23_containers/span/layout_compat.cc | 48 |
2 files changed, 54 insertions, 6 deletions
diff --git a/libstdc++-v3/include/std/span b/libstdc++-v3/include/std/span index fb34940..24c61ba 100644 --- a/libstdc++-v3/include/std/span +++ b/libstdc++-v3/include/std/span @@ -38,8 +38,8 @@ #if __cplusplus > 201703L -#include <type_traits> #include <array> +#include <cstddef> #include <bits/stl_iterator.h> #include <bits/ranges_base.h> @@ -151,7 +151,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION constexpr span() noexcept requires ((_Extent + 1u) <= 1u) - : _M_extent(0), _M_ptr(nullptr) + : _M_ptr(nullptr), _M_extent(0) { } template<contiguous_iterator _It> @@ -159,7 +159,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION constexpr explicit(extent != dynamic_extent) span(_It __first, size_type __count) noexcept - : _M_extent(__count), _M_ptr(std::to_address(__first)) + : _M_ptr(std::to_address(__first)), _M_extent(__count) { if constexpr (_Extent != dynamic_extent) { @@ -173,8 +173,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION constexpr explicit(extent != dynamic_extent) span(_It __first, _End __last) noexcept(noexcept(__last - __first)) - : _M_extent(static_cast<size_type>(__last - __first)), - _M_ptr(std::to_address(__first)) + : _M_ptr(std::to_address(__first)), + _M_extent(static_cast<size_type>(__last - __first)) { if constexpr (_Extent != dynamic_extent) { @@ -392,8 +392,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION } private: - [[no_unique_address]] __detail::__extent_storage<extent> _M_extent; pointer _M_ptr; + [[no_unique_address]] __detail::__extent_storage<extent> _M_extent; }; // deduction guides diff --git a/libstdc++-v3/testsuite/23_containers/span/layout_compat.cc b/libstdc++-v3/testsuite/23_containers/span/layout_compat.cc new file mode 100644 index 0000000..efc5b8e --- /dev/null +++ b/libstdc++-v3/testsuite/23_containers/span/layout_compat.cc @@ -0,0 +1,48 @@ +// Copyright (C) 2020 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// <http://www.gnu.org/licenses/>. + +// { dg-options "-std=gnu++2a" } +// { dg-do compile { target c++2a } } + +#include <span> +#include <cstddef> + +#if __has_include(<sys/uio.h>) +#include <sys/uio.h> +#else +struct iovec { void* iov_base; std::size_t iov_len; }; +#endif + +#if __cpp_lib_is_pointer_interconvertible +using std::is_layout_compatible_v; +#else +// A poor substitute for is_layout_compatible_v +template<typename T, typename U> + constexpr bool is_layout_compatible_v + = std::is_standard_layout_v<T> && std::is_standard_layout_v<U> + && sizeof(T) == sizeof(U) && alignof(T) == alignof(U); +#endif + +void +test_pr95609() +{ + using rbuf = std::span<const std::byte>; + using wbuf = std::span<std::byte>; + + static_assert(is_layout_compatible_v<rbuf, struct iovec>); + static_assert(is_layout_compatible_v<wbuf, struct iovec>); +} |