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From: "hewillk at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/111410] New: Bogus Wdangling-reference warning with ranges
 pipe expression in for loop
Date: Thu, 14 Sep 2023 01:09:58 +0000
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X-Bugzilla-Component: c++
X-Bugzilla-Version: 14.0
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D111410

            Bug ID: 111410
           Summary: Bogus Wdangling-reference warning with ranges pipe
                    expression in for loop
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hewillk at gmail dot com
  Target Milestone: ---

#include <iostream>
#include <vector>
#include <ranges>

int main()
{
  std::vector v{1, 2, 3, 4, 5};
  for (auto i : std::span{v} | std::views::take(1))
    std::cout << i << '\n';
}

GCC-trunk reports the following warning when the -Wall flag is used:

<source>:8:51: warning: possibly dangling reference to a temporary
[-Wdangling-reference]
    8 |   for ( auto i : std::span{v} | std::views::take(1))
      |                                                   ^


https://godbolt.org/z/5jhnTTej9=