Weird error on nested map

[Simen kjaeraas]

auto fn1 = ( string s ) {
	return s;
};

auto fn2 = ( string s ) {
	return map!fn1( [""] );
};

auto idirs = map!fn2( [""] );

The above code gives the following errors:
foo.d(114): Error: struct foo.main.Map!(fn2,string[]).Map inner struct
Map cannot be a field
foo.d(114): Error: struct foo.main.Map!(fn2,string[]).Map inner struct
Map cannot be a field

As far as I can see, this has to do with struct rules, but I can't see
how to fix it. Should I file this in bugzilla?

-- 
Simen