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.
There doesn't appear to be an explicit prohibition of a function declaration of the form
auto f() -> decltype(f());
Presumably there should be.
Rationale (February, 2012):
As noted in issue 1433, the point of declaration of the function name is after the complete declarator, i.e., after the trailing return type, so the recursion posited in this issue cannot occur.