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From: "fchelnokov at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/115504] New: Wrong decltype result for a captured reference
 inside limbda
Date: Sat, 15 Jun 2024 12:55:20 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
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X-Bugzilla-Product: gcc
X-Bugzilla-Component: c++
X-Bugzilla-Version: 14.1.1
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X-Bugzilla-Severity: normal
X-Bugzilla-Who: fchelnokov at gmail dot com
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X-Bugzilla-Priority: P3
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D115504

            Bug ID: 115504
           Summary: Wrong decltype result for a captured reference inside
                    limbda
           Product: gcc
           Version: 14.1.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: fchelnokov at gmail dot com
  Target Milestone: ---

This program
```
template<class T> int foo() =3D delete;
template<> int foo<int&>() { return 0; }

int main() {=20
    int y =3D 0;
    int &i =3D y;
    return [&i]() {
        decltype(auto) x =3D i;
        return foo<decltype(x)>();
    }();
}
```
is accepted in Clang, MSVC and GCC 13.3, but not in GCC 14, which thinks th=
at
`decltype(x)=3Dint`. Online demo: https://gcc.godbolt.org/z/fc1nrP4P9

Related discussion: https://stackoverflow.com/a/78626163/7325599=