}
}
- if constexpr (sized_sentinel_for<_Sent, _Iter>)
+ if constexpr (sized_sentinel_for<_Sent, _Iter>
+ && random_access_iterator<_Iter>)
{
auto __tail_size = __last - __first;
auto __remainder = __count;
if (--__remainder == 0)
return {__first - __count, __first};
}
+ __remainder = __count + 1 - (__first - __backtrack);
}
auto __i = __first + __tail_size;
return {__i, __i};
--- /dev/null
+// 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 run { target c++2a } }
+
+// PR libstdc++/97828
+
+#include <algorithm>
+#include <testsuite_hooks.h>
+#include <testsuite_iterators.h>
+
+using __gnu_test::test_sized_range;
+using __gnu_test::forward_iterator_wrapper;
+using __gnu_test::random_access_iterator_wrapper;
+
+template<template<typename> typename Wrapper>
+void
+test01()
+{
+ int x[] = {0,42,42,0,42,42,42};
+ test_sized_range<int, Wrapper> rx(x);
+ auto res = std::ranges::search_n(rx, 3, 42);
+ VERIFY( res.begin().ptr == x+4 && res.end().ptr == x+7 );
+}
+
+template<template<typename> typename Wrapper>
+void
+test02()
+{
+ int x[] = {0,42,42,0,42};
+ test_sized_range<int, Wrapper> rx(x);
+ auto res = std::ranges::search_n(rx, 3, 42);
+ VERIFY( res.begin().ptr == x+5 && res.end().ptr == x+5 );
+}
+
+int
+main()
+{
+ test01<forward_iterator_wrapper>();
+ test01<random_access_iterator_wrapper>();
+ test02<forward_iterator_wrapper>();
+ test02<random_access_iterator_wrapper>();
+}