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From: "danakj at orodu dot net" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/108067] New: Miscompilation with friend function with parameter pack: mismatched argument pack lengths Date: Mon, 12 Dec 2022 06:11:30 +0000 [thread overview] Message-ID: <bug-108067-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108067 Bug ID: 108067 Summary: Miscompilation with friend function with parameter pack: mismatched argument pack lengths Product: gcc Version: 12.2.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: danakj at orodu dot net Target Milestone: --- The following code compiles in Clang and MSVC but not in GCC. Repros in GCC 10, 11, 12, and trunk. ``` template <class A, class B> static constexpr bool C = true; template <class... Ts> struct Foo { template <class... Us> requires((... && C<Ts, Us>)) void bar(const Foo<Us...>& r) {} template <class... Us> requires((... && C<Ts, Us>)) friend void baz(const Foo& l, const Foo<Us...>& r) {} }; int main() { Foo<int, int> x; x.bar(Foo<int, int>()); // Works. baz(x, Foo<int, int>()); // Doesn't work. } ``` godbolt: https://godbolt.org/z/3Ybofbcoc <source>: In instantiation of 'struct Foo<int, int>': <source>:16:19: required from here <source>:12:17: error: mismatched argument pack lengths while expanding 'C<Ts, Us>' 12 | friend void baz(const Foo& l, const Foo<Us...>& r) {} | ^~~ ASM generation compiler returned: 1 <source>: In instantiation of 'struct Foo<int, int>': <source>:16:19: required from here <source>:12:17: error: mismatched argument pack lengths while expanding 'C<Ts, Us>' 12 | friend void baz(const Foo& l, const Foo<Us...>& r) {} | ^~~ Execution build compiler returned: 1
next reply other threads:[~2022-12-12 6:11 UTC|newest] Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-12-12 6:11 danakj at orodu dot net [this message] 2022-12-12 6:15 ` [Bug c++/108067] " danakj at orodu dot net 2022-12-12 13:29 ` marxin at gcc dot gnu.org 2022-12-12 17:19 ` ppalka at gcc dot gnu.org 2022-12-21 16:09 ` ppalka at gcc dot gnu.org
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