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From: "zeratul976 at hotmail dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/52145] New: [C++11] zero-valued integer constant expression should prefer conversion to pointer Date: Tue, 07 Feb 2012 01:00:00 -0000 [thread overview] Message-ID: <bug-52145-4@http.gcc.gnu.org/bugzilla/> (raw) http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52145 Bug #: 52145 Summary: [C++11] zero-valued integer constant expression should prefer conversion to pointer Classification: Unclassified Product: gcc Version: 4.7.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ AssignedTo: unassigned@gcc.gnu.org ReportedBy: zeratul976@hotmail.com In the following example: #include <iostream> using std::cerr; struct S { int n; }; struct X { X(int) {} }; void f(void*) { cerr << "Pointer!\n"; } void f(X) { cerr << "X!\n"; } int main() { f(S().n); } With GCC 4.7.0-20120128 with the --std=c++11 flag, the output is "X!". The correct output would be "Pointer!". The reason is that S's implicit default constructor is constexpr, so it value-initializes n. Therefore S().n is a zero-valued integer constant expression, whose conversion to a pointer is preferred over the user-defined conversion to X. (This example was taken from Chandler Carruth's talk at the GoingNative 2012 conference.)
next reply other threads:[~2012-02-07 1:00 UTC|newest] Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top 2012-02-07 1:00 zeratul976 at hotmail dot com [this message] 2012-02-07 13:52 ` [Bug c++/52145] " daniel.kruegler at googlemail dot com 2012-02-07 14:39 ` [Bug c++/52145] [C++11] [DR 903] " redi at gcc dot gnu.org 2012-04-26 19:43 ` jyasskin at gcc dot gnu.org 2012-04-26 23:03 ` paolo.carlini at oracle dot com 2012-04-26 23:06 ` jyasskin at gcc dot gnu.org 2012-04-26 23:14 ` paolo.carlini at oracle dot com 2012-04-26 23:57 ` jyasskin at gcc dot gnu.org 2014-12-10 13:30 ` redi at gcc dot gnu.org 2021-12-04 6:43 ` pinskia at gcc dot gnu.org 2021-12-04 6:43 ` pinskia at gcc dot gnu.org 2021-12-04 6:52 ` pinskia at gcc dot gnu.org 2021-12-07 12:39 ` pinskia at gcc dot gnu.org 2022-10-14 15:14 ` pinskia at gcc dot gnu.org
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