This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 112c. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
[Moved to DR at the April, 2013 meeting.]
It appears that an example like
int operator"" _a (const char *, std::size_t = 0); int operator"" _a (const char *); int i = 123_a;
is ambiguous: although only the second declaration is a raw literal operator, the corresponding call
operator"" _a ("123")
could match either declaration. Should default arguments for literal operators be prohibited?
Proposed resolution (October, 2012):
Change 12.6 [over.literal] paragraph 3 as follows:
The declaration of a literal operator shall have a parameter-declaration-clause equivalent to one of the following: