http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54581
Bug #: 54581 Summary: decltype and opaque vector types Classification: Unclassified Product: gcc Version: 4.8.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ AssignedTo: unassig...@gcc.gnu.org ReportedBy: gli...@gcc.gnu.org As explained here: http://gcc.gnu.org/ml/gcc-patches/2012-09/msg01023.html it would be nice if decltype could remove the opacity from vector types. In particular: typedef double vec __attribute__((vector_size(2*sizeof(double)))); extern vec x; decltype(x<x) y={1,2}; should not complain.