http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53421
Bug #: 53421 Summary: __attribute((__may_alias__)) prevents taking address of conversion operator member function Classification: Unclassified Product: gcc Version: 4.6.3 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ AssignedTo: unassig...@gcc.gnu.org ReportedBy: jeffrey.hellr...@gmail.com Created attachment 27446 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27446 source file exhibiting the bug when compiled Compiling attached main.cpp gives the following error: jeffrey@ubuntu:~/scratch$ g++ -o scratch main.cpp main.cpp: In function ‘int main(int, char**)’: main.cpp:21:6: error: ‘operator Y<X>&’ is not a member of ‘X’ However, no error occurs with any of the following changes: (a) Removing the __attribute__((__may_alias__)) (commenting in line 3 and commenting out line 4). (b) Removing the implementation (line 8) or using a throwing implementation (line 9) rather than the present implementation (line 10). (c) Replacing the conversion operator with a regular member function (commenting out lines 10,21 and commenting in lines 11,22 or 12,22. Further investigation reveals a possibly related error. One can define the function out-of-line (commenting in lines 8,16 and commenting out line 10) with no error, as long as line 15 remains commented out; additionally commenting in line 15 gives the following error: jeffrey@ubuntu:~/scratch$ g++ -o scratch main.cpp main.cpp:16:20: error: no ‘X::operator Y<X>&()’ member function declared in class ‘X’ This error still appears if one uses a throwing implementation (like in (b)) or replaces the conversion operator with a regular member function (like in (c)), but no error occurs with the removal of the __attribute__((__may_alias__)) (as in (a)).