The demangler crashes when given this symbol:
Some more comments, copied from the GDB bug report:
Ok, this problem is a bit more complicated. First, a newer GCC (4.9.1) and Clang 3.5 doesn't produce the symbol any more. Running a more recent c++filt on it now crashes c++filt -- if you look closely, the originally demangled type was also incorrect, as: decltype (((float)()*(float)())) does not make sense -- should have been decltype (float ()*float ()) which is simply float.
I'm debugging a new crash now where the demangler/libiberty starts producing a symbol name with decltype in it, which I strongly suspect is similar to the original issue. Am I right to assume that decltype is never part of a mangled symbol name?
GNU c++filt (GNU Binutils) 220.127.116.1161118 doesn't crash and demangles it to:
std::enable_if<std::is_arithmetic<float>::value, niven::Color<decltype (((float)())*((float)())), 4> const>::type niven::Color<float, 4>::operator/<float>(float) const