http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54413
--- Comment #5 from Ed Smith-Rowland <3dw4rd at verizon dot net> 2012-10-01 18:47:33 UTC --- If I remember correctly, we are supposed to parse compiler-specific extensions before UDLs - i.e. The compiler extensions get dibs. I guess that's not the issue. You propose being able to turn off (presumably all?) gcc-specific suffix extensions. Presumably, these should be on by default for C++1*? I agree we should have something like this. Detecting at the level of c-family or the lexer whether c++ has seen a definition of operator"" r or i could be ... real interesting. Perhaps we could "move" these gnu extensions to: namespace __gnucxx{ operator"" r() } somehow.