Imported Upstream version 3.8.0

Former-commit-id: 6a76a29bd07d86e57c6c8da45c65ed5447d38a61

mcs/errors/cs0457-4.cs

@@ -0,0 +1,27 @@
+// CS0457: Ambiguous user defined operators `D.implicit operator D(System.Action)' and `D.explicit operator D(Foo)' when converting from `method group' to `D'
+// Line: 25
+
+using System;
+
+public delegate void Foo ();
+
+class D
+{
+	public static implicit operator D (Action d)
+	{
+		return new D ();
+	}
+
+	public static explicit operator D (Foo d)
+	{
+		return new D ();
+	}
+}
+
+class Program
+{
+	static void Main()
+	{
+		D d = (D) Main;
+	}
+}