Bug 10021 – auto return type and covariance

This snippet: interface I { I makeI(); } class D : I { D makeI() { return this; } } class C : I { auto makeI() { return this; } } does not compile. It fails in the third line with Error: function C.makeI of type () overrides but is not covariant with I.makeI of type I() I think this should compile, especially because class D with explicit return type compiles fine. It seems to me that covariance with the interface is checked for before the return type is inferred.

*** This issue has been marked as a duplicate of issue 8318 ***