The big problem here is that it shouldn’t allow this in the first place (same issue as FARPROC to Func). Func and friends are “block” delegates, in that they capture a self pointer too and end up as a class (Delegate in Island/Echoes), which isn’t compatible with function pointers.
We don’t currently have a syntax for function pointers in swift, but I see Swift now has one, so expect this one to work for fridays build:
typealias MyFunc = @convention(c) () -> Bool
var pFoo = GetProcAddress(hSilverDLL1, "_Foo@0");
var x = pFoo as? MyFunc