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When a generic function constraint inherits from another constraint, the latter is not propagated when compiling and we get a CS1061 error. I have tested with Mono 18.104.22.168 (mcs --version says "Mono C# compiler version 22.214.171.124").
The following example compiles successfully with Visual Studio 2013 (target framework: tested with .NET Framework 4.5 and 2.0), but doesn't compile with Mono.
public class A
public void F()
public class B : A
public class C : B
public void Test()
GenericF<B, C>(new C());
private void GenericF<T1, T2>(T2 t2)
where T1 : B
where T2 : T1
t2.F(); // T2 is T1, T1 is B, so T2 is be B and contains F(). CS1061
Already fixed in master and Mono 4.4