Imported Upstream version 3.10.0

Former-commit-id: 172c8e3c300b39d5785c7a3e8dfb08ebdbc1a99b

mcs/tests/test-null-operator-08.cs

@@ -0,0 +1,93 @@
+using System;
+
+interface I
+{
+	void Foo (bool expected);
+}
+
+struct S : I
+{
+	bool flag;
+
+	public void Foo (bool expected)
+	{
+		Console.WriteLine (flag);
+		if (expected != flag)
+			throw new ApplicationException ();
+
+		flag = true;
+	}
+}
+
+class Program
+{
+	static void M<T> (T x)
+	{
+		object s = x?.ToString ();
+		System.Console.WriteLine (s);
+
+		var h = x?.GetHashCode ();
+		System.Console.WriteLine (h);
+	}
+
+	static void M2<T> (T[] x)
+	{
+		object s = x?.ToString ();
+		System.Console.WriteLine (s);
+
+		var h = x?.GetHashCode ();
+		System.Console.WriteLine (h);
+	}
+
+	static void M2_2<T> (T[] x)
+	{
+		object s = x[0]?.ToString ();
+		System.Console.WriteLine (s);
+
+		var h = x[0]?.GetHashCode ();
+		System.Console.WriteLine (h);
+	}
+
+	static void M3<T> (T? x) where T : struct
+	{
+		object s = x?.ToString ();
+		System.Console.WriteLine (s);
+
+		var h = x?.GetHashCode ();
+		System.Console.WriteLine (h);
+	}
+
+	static void TestAddress_1<T> (T t) where T : I
+	{
+		t?.Foo (false);
+		t?.Foo (true);
+	}
+
+	static void TestAddress_2<T> (T[] t) where T : I
+	{
+		t[0]?.Foo (false);
+		t[0]?.Foo (true);
+	}
+
+	static void Main()
+	{
+		M<string> (null);
+		M (1);
+		M("X");
+
+		M2<int> (null);
+		M2<string> (null);
+		M2 (new [] { 1 });
+		M2 (new [] { "x" });
+
+		M2_2 (new string [1]);
+		M2_2 (new int [1]);
+
+		M3<int> (1);
+		M3<byte> (null);
+
+		TestAddress_1 (new S ());
+		var ar = new [] { new S () };
+		TestAddress_2 (ar);
+	}
+}