http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54047
Bug #: 54047 Summary: unused variable warning not for std::string Classification: Unclassified Product: gcc Version: 4.8.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ AssignedTo: unassig...@gcc.gnu.org ReportedBy: plasm...@gmx.net Compiling the following code: #include <string> struct A { }; void foo() { A z; std::string z0; } I get a warning for unused variable z, but not for variable z0. It seems that std::string is somehow magical here, but I can't see how or why.