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author | Jonathan Wakely <jwakely@redhat.com> | 2020-08-19 20:36:10 +0100 |
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committer | Jonathan Wakely <jwakely@redhat.com> | 2020-08-19 20:36:10 +0100 |
commit | e6e01618e83bcd9eb3a2b27df30ed87106a748b4 (patch) | |
tree | 59cd46e74d878fe3800ca553e434e8adcc1cb92b | |
parent | 23ebfda0e352fa0a92c6b012458ecb65505a135f (diff) | |
download | gcc-e6e01618e83bcd9eb3a2b27df30ed87106a748b4.zip gcc-e6e01618e83bcd9eb3a2b27df30ed87106a748b4.tar.gz gcc-e6e01618e83bcd9eb3a2b27df30ed87106a748b4.tar.bz2 |
libstdc++: Make make-unsigned-like-t<__int128> work [PR 96042]
As well as ensuring that numeric_limits<__int128> is defined, we need to
ensure that make-unsigned-like-t and to-unsigned-like work correctly for
128-bit integers in strict mode. This ensures that a subrange created
from an iota_view's iterator and sentinel can represent its size.
Co-authored-by: Patrick Palka <ppalka@redhat.com>
libstdc++-v3/ChangeLog:
2020-08-19 Jonathan Wakely <jwakely@redhat.com>
Patrick Palka <ppalka@redhat.com>
PR libstdc++/96042
* include/bits/range_access.h (__detail::__to_unsigned_like):
Do not use make_unsigned_t<T> in the return type, as it can
result in an error before the integral<T> constraint is checked.
[__STRICT_ANSI__]: Add overloads for 128-bit integer types.
(__detail::__make_unsigned_like_t): Define as the return type
of __to_unsigned_like.
* testsuite/std/ranges/subrange/96042.cc: New test.
-rw-r--r-- | libstdc++-v3/include/bits/range_access.h | 18 | ||||
-rw-r--r-- | libstdc++-v3/testsuite/std/ranges/subrange/96042.cc | 34 |
2 files changed, 48 insertions, 4 deletions
diff --git a/libstdc++-v3/include/bits/range_access.h b/libstdc++-v3/include/bits/range_access.h index 3eb1f2f..bafced3 100644 --- a/libstdc++-v3/include/bits/range_access.h +++ b/libstdc++-v3/include/bits/range_access.h @@ -364,13 +364,23 @@ namespace ranges { return __max_size_type(__t); } template<integral _Tp> - constexpr make_unsigned_t<_Tp> + constexpr auto __to_unsigned_like(_Tp __t) noexcept - { return __t; } + { return static_cast<make_unsigned_t<_Tp>>(__t); } - template<typename _Tp, bool _MaxDiff = same_as<_Tp, __max_diff_type>> +#if defined __STRICT_ANSI__ && defined __SIZEOF_INT128__ + constexpr unsigned __int128 + __to_unsigned_like(__int128 __t) noexcept + { return __t; } + + constexpr unsigned __int128 + __to_unsigned_like(unsigned __int128 __t) noexcept + { return __t; } +#endif + + template<typename _Tp> using __make_unsigned_like_t - = conditional_t<_MaxDiff, __max_size_type, make_unsigned_t<_Tp>>; + = decltype(__detail::__to_unsigned_like(std::declval<_Tp>())); // Part of the constraints of ranges::borrowed_range template<typename _Tp> diff --git a/libstdc++-v3/testsuite/std/ranges/subrange/96042.cc b/libstdc++-v3/testsuite/std/ranges/subrange/96042.cc new file mode 100644 index 0000000..5826203 --- /dev/null +++ b/libstdc++-v3/testsuite/std/ranges/subrange/96042.cc @@ -0,0 +1,34 @@ +// 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=c++20" } +// { dg-do compile { target c++2a } } + +#include <ranges> + +constexpr bool +test01() +{ + using I = unsigned long long; + // view with a difference type that doesn't fit in long long: + std::ranges::iota_view<I, I> v(0, std::numeric_limits<I>::max()); + // view with a size type that doesn't fit in unsigned long long: + std::ranges::subrange sr{v.begin(), v.end()}; + auto sz = std::ranges::size(sr); + return sz == std::numeric_limits<I>::max(); +} +static_assert( test01() ); |