struct Blub { alias const(void*) T; ~this() {} invariant() {} } $ dmd -c wrapper.d DMD v2.054 DEBUG Error: __result = this is not mutable Error: __result = this is not an lvalue Somehwat related to bug 5690 but this one doesn't show an error location and there is no "real" const member, just an alias.
I think this is bug 3273, and it is already fixed in master. Your sample code pass compile with trunk dmd.