Cannot interpret struct at compile time

[Robert Clipsham]

Hey all,

I was wondering if anyone could enlighten me as to why the following 
code does not compile (dmd2, latest release or the beta):
----
struct Foo
{
     int a;
}

string test()
{
         string str = "struct " ~ Foo.stringof ~ "_{";
         foreach (j, f; Foo.tupleof)
         {
             enum fullFieldName = Foo.tupleof[j].stringof;
             str ~= typeof(f).stringof ~ ' ' ~ 
fullFieldName[Foo.stringof.length + 3 .. $];
         }
         return str ~ "}";
}

void main()
{
     mixin(test());
}
----
If fails with the errors:
test.d(9): Error: Cannot interpret Foo at compile time
test.d(19): Error: cannot evaluate test() at compile time
test.d(19): Error: argument to mixin must be a string, not (test())
test.d(19): Error: cannot evaluate test() at compile time
test.d(19): Error: argument to mixin must be a string, not (test())

Thanks,

-- 
Robert
http://octarineparrot.com/