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* [Bug c++/105716] New: CTAD failure with member function returning auto as template argument
@ 2022-05-24  9:30 j-l.wynen at hotmail dot de
  2022-05-24 10:14 ` [Bug c++/105716] [12/13 Regression] " rguenth at gcc dot gnu.org
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: j-l.wynen at hotmail dot de @ 2022-05-24  9:30 UTC (permalink / raw)
  To: gcc-bugs

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105716

            Bug ID: 105716
           Summary: CTAD failure with member function returning auto as
                    template argument
           Product: gcc
           Version: 12.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: j-l.wynen at hotmail dot de
  Target Milestone: ---

gcc 12 fails to compile the following code (tested 12.1 and trunk). Tried with
c++17 and c++20.

template <class T> struct Func {
  static auto apply() {}
};

template <class T>
struct A {
    T x;
};

template <class T>
A(T) -> A<T>;

int main() {
    A a{Func<double>::apply};
}

with an error of

error: 'A<auto (*)()> a' has incomplete type

The code compiles fine with gcc 11, 10, and 9 as well as clang and MSCV.

Changing static auto apply() {} to static void apply() {} or any other concrete
return type (and proper return statement) makes the code compiles.

Also, specifying the template argument of A in main makes it compile.

https://godbolt.org/z/c9cGnGEPq

^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2022-05-25 17:08 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-05-24  9:30 [Bug c++/105716] New: CTAD failure with member function returning auto as template argument j-l.wynen at hotmail dot de
2022-05-24 10:14 ` [Bug c++/105716] [12/13 Regression] " rguenth at gcc dot gnu.org
2022-05-24 13:34 ` ppalka at gcc dot gnu.org
2022-05-25 17:08 ` jason at gcc dot gnu.org

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