This is an unofficial snapshot of the ISO/IEC JTC1 SC22 WG21 Core Issues List revision 112e. See http://www.open-std.org/jtc1/sc22/wg21/ for the official list.
[Moved to DR at the November, 2014 meeting.]
Although repeated type-specifiers such as const are forbidden, there is no such prohibition against repeated non-type specifiers like constexpr and virtual. Should there be?
On the “con” side, it's not clear that such a prohibition actually helps anyone; it could happen via macros, and a warning about non-macro use could be a QoI issue. Also, C99 moved in the opposite direction, removing the prohibition against repeated cv-qualifiers.
Proposed resolution (February, 2014):
Add the following as a new paragraph before 9.2 [dcl.spec] paragraph 2:
If a type-name is encountered...