Feature request:

Via copy/paste I ended up with this in some local code:

class SomeVeryLongTypeName
  : public GarbageCollected<SomeVeryLongType> {
  USING_GARBAGE_COLLECTED_MIXIN(SomeVeryLongTypeName)
public:
  ...
  DEFINE_VIRTUAL_TRACE();
  ...
}

Note the type name mismatch - SomeVeryLongTypeName vs. GarbageCollected<SomeVeryLongType>

This compiled just fine, and manifested as a crash when GC kicked in. Existing layout tests didn't catch it.

"It would be nice if..."

The clang plugin could detect a mismatch here and report an error.

This presumably could be generalized to handle RefCounted, ActiveScriptWrappable, etc - a list of types where you should not be specifying a templated base type that doesn't match the derived type.