I ran across this while searching for a way to use types with switch/case statements.

F:\>dmd error
Assertion failure: '0' on line 2055 in file 'expression.c'

abnormal program termination

Offending code:
-------error.d-------
void main()
{
  TFoo!(int).t; // should produce a "no identifier" error.
}
template TFoo(T) { alias T* t; }