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From: "fchelnokov at gmail dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/113529] New: Incorrect result of requires-expression in case of function call ambiguity Date: Sun, 21 Jan 2024 08:51:31 +0000 [thread overview] Message-ID: <bug-113529-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113529 Bug ID: 113529 Summary: Incorrect result of requires-expression in case of function call ambiguity Product: gcc Version: 13.2.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: fchelnokov at gmail dot com Target Milestone: --- In this program #include <compare> struct A { auto operator <=>(const A&) const = default; bool operator <(const A&) const = default; }; struct B { auto operator <=>(const B&) const = default; }; struct C : A, B {}; template<typename T> concept Cmp = requires(T u, T v) { u < v; }; //auto cmp = C{} < C{}; //this correctly fails due to ambiguity static_assert( !Cmp<C> ); //but this evaluates wrongly in GCC C{} < C{} is correctly rejected as ambiguous, but for some reason `requires` in GCC returns that the objects can be compared. This program is accepted by Clang truck (to be v18). Online demo: https://godbolt.org/z/76zoYMd6h Explanation of ambiguity: https://stackoverflow.com/a/69245639/7325599
next reply other threads:[~2024-01-21 8:51 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-01-21 8:51 fchelnokov at gmail dot com [this message] 2024-01-21 9:03 ` [Bug c++/113529] Incorrect result of requires-expression in case of function call ambiguity and `operator<=>` pinskia at gcc dot gnu.org 2024-01-22 18:15 ` ppalka at gcc dot gnu.org 2024-01-24 22:11 ` cvs-commit at gcc dot gnu.org 2024-01-26 14:42 ` cvs-commit at gcc dot gnu.org 2024-01-26 14:43 ` ppalka at gcc dot gnu.org
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