The __iota_diff_t alias can be the type __int128, but that does not
satisfy the signed_integral and __is_signed_integer_like concepts when
__STRICT_ANSI__ is defined (which is true for -std=c++2a).
Because weakly_incrementable is defined in terms of signed_integral, it
is not satisfied by __int128, which means iota_view's iterator doesn't
always satisfy input_or_output_iterator and so iota_view is not always a
range.
The solution is to define __max_size_type and __max_diff_type using
__int128, so that __is_signed_integer_like allows __int128, and then
make weakly_incrementable use __is_signed_integer_like instead of
signed_integral.
PR libstdc++/93267
* include/bits/iterator_concepts.h (__max_diff_type, __max_size_type):
Move here from <bits/range_access.h> and define using __int128 when
available.
(__is_integer_like, __is_signed_integer_like): Move here from
<bits/range_access.h>.
(weakly_incrementable): Use __is_signed_integer_like.
* include/bits/range_access.h (__max_diff_type, __max_size_type)
(__is_integer_like, __is_signed_integer_like): Move to
<bits/iterator_concepts.h>.
(__make_unsigned_like_t): Move here from <ranges>.
* include/std/ranges (__make_unsigned_like_t): Move to
<bits/range_access.h>.
(iota_view): Replace using-directive with using-declarations.
* testsuite/std/ranges/iota/93267.cc: New test.
* testsuite/std/ranges/iota_view.cc: Move to new 'iota' sub-directory.
Tested powerpc64le-linux, committed to trunk.
commit 2a0f6c61b4db19535c632be68bddad74b6adb6cf
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Wed Jan 15 14:09:35 2020 +0000
libstdc++: Fix weakly_incrementable to allow __int128 (PR 93267)
The __iota_diff_t alias can be the type __int128, but that does not
satisfy the signed_integral and __is_signed_integer_like concepts when
__STRICT_ANSI__ is defined (which is true for -std=c++2a).
Because weakly_incrementable is defined in terms of signed_integral, it
is not satisfied by __int128, which means iota_view's iterator doesn't
always satisfy input_or_output_iterator and so iota_view is not always a
range.
The solution is to define __max_size_type and __max_diff_type using
__int128, so that __is_signed_integer_like allows __int128, and then
make weakly_incrementable use __is_signed_integer_like instead of
signed_integral.
PR libstdc++/93267
* include/bits/iterator_concepts.h (__max_diff_type,
__max_size_type):
Move here from <bits/range_access.h> and define using __int128 when
available.
(__is_integer_like, __is_signed_integer_like): Move here from
<bits/range_access.h>.
(weakly_incrementable): Use __is_signed_integer_like.
* include/bits/range_access.h (__max_diff_type, __max_size_type)
(__is_integer_like, __is_signed_integer_like): Move to
<bits/iterator_concepts.h>.
(__make_unsigned_like_t): Move here from <ranges>.
* include/std/ranges (__make_unsigned_like_t): Move to
<bits/range_access.h>.
(iota_view): Replace using-directive with using-declarations.
* testsuite/std/ranges/iota/93267.cc: New test.
* testsuite/std/ranges/iota_view.cc: Move to new 'iota'
sub-directory.
diff --git a/libstdc++-v3/include/bits/iterator_concepts.h
b/libstdc++-v3/include/bits/iterator_concepts.h
index 4ba32a0859e..bf581597229 100644
--- a/libstdc++-v3/include/bits/iterator_concepts.h
+++ b/libstdc++-v3/include/bits/iterator_concepts.h
@@ -492,6 +492,28 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
= std::forward<_Tp>(__t);
};
+ namespace ranges::__detail
+ {
+#if __SIZEOF_INT128__
+ using __max_diff_type = __int128;
+ using __max_size_type = unsigned __int128;
+#else
+ using __max_diff_type = long long;
+ using __max_size_type = unsigned long long;
+#endif
+
+ template<typename _Tp>
+ concept __is_integer_like = integral<_Tp>
+ || same_as<_Tp, __max_diff_type> || same_as<_Tp, __max_size_type>;
+
+ template<typename _Tp>
+ concept __is_signed_integer_like = signed_integral<_Tp>
+ || same_as<_Tp, __max_diff_type>;
+
+ } // namespace ranges::__detail
+
+ namespace __detail { using ranges::__detail::__is_signed_integer_like; }
+
/// Requirements on types that can be incremented with ++.
template<typename _Iter>
concept weakly_incrementable = default_initializable<_Iter>
@@ -499,7 +521,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
&& requires(_Iter __i)
{
typename iter_difference_t<_Iter>;
- requires signed_integral<iter_difference_t<_Iter>>;
+ requires __detail::__is_signed_integer_like<iter_difference_t<_Iter>>;
{ ++__i } -> same_as<_Iter&>;
__i++;
};
diff --git a/libstdc++-v3/include/bits/range_access.h
b/libstdc++-v3/include/bits/range_access.h
index 721c755f48c..8b546a58840 100644
--- a/libstdc++-v3/include/bits/range_access.h
+++ b/libstdc++-v3/include/bits/range_access.h
@@ -347,22 +347,15 @@ namespace ranges
namespace __detail
{
- using __max_diff_type = long long;
- using __max_size_type = unsigned long long;
-
- template<typename _Tp>
- concept __is_integer_like = integral<_Tp>
- || same_as<_Tp, __max_diff_type> || same_as<_Tp, __max_size_type>;
-
- template<typename _Tp>
- concept __is_signed_integer_like = signed_integral<_Tp>
- || same_as<_Tp, __max_diff_type>;
-
template<integral _Tp>
constexpr make_unsigned_t<_Tp>
__to_unsigned_like(_Tp __t) noexcept
{ return __t; }
+ template<typename _Tp, bool _MaxDiff = same_as<_Tp, __max_diff_type>>
+ using __make_unsigned_like_t
+ = conditional_t<_MaxDiff, __max_size_type, make_unsigned_t<_Tp>>;
+
// Part of the constraints of ranges::safe_range
template<typename _Tp>
concept __maybe_safe_range
diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges
index 888414a8fd6..ea558c76c9d 100644
--- a/libstdc++-v3/include/std/ranges
+++ b/libstdc++-v3/include/std/ranges
@@ -244,10 +244,6 @@ namespace ranges
= !range<_Tp> && __pair_like<_Tp>
&& sentinel_for<tuple_element_t<1, _Tp>, tuple_element_t<0, _Tp>>;
- template<typename _Tp, bool _MaxDiff = same_as<_Tp, __max_diff_type>>
- using __make_unsigned_like_t
- = conditional_t<_MaxDiff, __max_size_type, make_unsigned_t<_Tp>>;
-
} // namespace __detail
enum class subrange_kind : bool { unsized, sized };
@@ -717,7 +713,8 @@ namespace ranges
constexpr _Iterator&
operator+=(difference_type __n) requires __detail::__advanceable<_Winc>
{
- using namespace __detail;
+ using __detail::__is_integer_like;
+ using __detail::__is_signed_integer_like;
if constexpr (__is_integer_like<_Winc>
&& !__is_signed_integer_like<_Winc>)
{
@@ -734,7 +731,8 @@ namespace ranges
constexpr _Iterator&
operator-=(difference_type __n) requires __detail::__advanceable<_Winc>
{
- using namespace __detail;
+ using __detail::__is_integer_like;
+ using __detail::__is_signed_integer_like;
if constexpr (__is_integer_like<_Winc>
&& !__is_signed_integer_like<_Winc>)
{
@@ -804,7 +802,8 @@ namespace ranges
operator-(const _Iterator& __x, const _Iterator& __y)
requires __detail::__advanceable<_Winc>
{
- using namespace __detail;
+ using __detail::__is_integer_like;
+ using __detail::__is_signed_integer_like;
using _Dt = difference_type;
if constexpr (__is_integer_like<_Winc>)
{
@@ -892,7 +891,8 @@ namespace ranges
|| (integral<_Winc> && integral<_Bound>)
|| sized_sentinel_for<_Bound, _Winc>
{
- using namespace __detail;
+ using __detail::__is_integer_like;
+ using __detail::__to_unsigned_like;
if constexpr (__is_integer_like<_Winc> && __is_integer_like<_Bound>)
return (_M_value < 0)
? ((_M_bound < 0)
diff --git a/libstdc++-v3/testsuite/std/ranges/iota/93267.cc
b/libstdc++-v3/testsuite/std/ranges/iota/93267.cc
new file mode 100644
index 00000000000..39b3c771b54
--- /dev/null
+++ b/libstdc++-v3/testsuite/std/ranges/iota/93267.cc
@@ -0,0 +1,30 @@
+// 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++2a" }
+// { dg-do compile { target c++2a } }
+
+#include <ranges>
+
+void
+test01()
+{
+ // PR libstdc++/93267
+ std::ranges::iota_view<long long, int> i(0, 3);
+ static_assert( std::weakly_incrementable<decltype(i.begin())> );
+ (void) std::ranges::begin(i);
+}
