http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48003
--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-03-07 13:42:37 UTC --- http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#699 added integer overflow ("a result that is not mathematically defined or not in the range of representable values for its type") to the list of things that cause an expression to not be a constant expression The non-type template argument needs to be an integral constant-expression, but it's not a constant expression due to the overflow, so the code is invalid. Whether it should be accepted with -fpermissive is a separate matter, as is the quality of diagnostic.
