[mcs] Implements C# 7.0 discards

8 files changed, 98 insertions, 0 deletions

diff --git a/mcs/errors/cs0029-42.cs b/mcs/errors/cs0029-42.cs
new file mode 100644
index 00000000000..c7671000c76
--- /dev/null
+++ b/mcs/errors/cs0029-42.cs
@@ -0,0 +1,10 @@
+// CS0029: Cannot implicitly convert type `string' to `int'
+// Line: 8
+
+class C
+{
+	void Exists (int _)
+	{
+		_ = "2";
+	}	
+}
\ No newline at end of file
diff --git a/mcs/errors/cs0103-18.cs b/mcs/errors/cs0103-18.cs
new file mode 100644
index 00000000000..8cec755d23d
--- /dev/null
+++ b/mcs/errors/cs0103-18.cs
@@ -0,0 +1,10 @@
+// CS0103: The name `_' does not exist in the current context
+// Line: 8
+
+class C
+{
+	void Test ()
+	{
+		_.ToString ();
+	}
+}
\ No newline at end of file
diff --git a/mcs/errors/cs1644-60.cs b/mcs/errors/cs1644-60.cs
new file mode 100644
index 00000000000..ca9547bc561
--- /dev/null
+++ b/mcs/errors/cs1644-60.cs
@@ -0,0 +1,11 @@
+// CS1644: Feature `discards' cannot be used because it is not part of the C# 6.0 language specification
+// Line: 9
+// Compiler options: -langversion:6
+
+class X
+{
+	int Test ()
+	{
+		_ = 2;
+	}
+}
diff --git a/mcs/errors/cs8183.cs b/mcs/errors/cs8183.cs
new file mode 100644
index 00000000000..f9e9004b737
--- /dev/null
+++ b/mcs/errors/cs8183.cs
@@ -0,0 +1,11 @@
+// CS8183: Cannot infer the type of implicitly-typed discard
+// Line: 9
+// Compiler options: -langversion:7.2
+
+class X
+{
+	public static void Main ()
+	{
+		_ = default;
+	}
+}
\ No newline at end of file
diff --git a/mcs/errors/cs8207.cs b/mcs/errors/cs8207.cs
new file mode 100644
index 00000000000..31090948b45
--- /dev/null
+++ b/mcs/errors/cs8207.cs
@@ -0,0 +1,19 @@
+// CS8207: An expression tree cannot contain a discard
+// Line: 11
+
+using System;
+using System.Linq.Expressions;
+
+class X
+{
+	void Test ()
+	{
+		Expression<Func<bool>> e = () => TryGetValue (out _);
+	}
+
+	bool TryGetValue (out int arg)
+	{
+		arg = 3;
+		return true;
+	}
+}
diff --git a/mcs/errors/cs8209.cs b/mcs/errors/cs8209.cs
new file mode 100644
index 00000000000..3a46a206c8e
--- /dev/null
+++ b/mcs/errors/cs8209.cs
@@ -0,0 +1,10 @@
+// CS8209: Cannot assign void to a discard
+// Line: 8
+
+class C
+{
+	public static void Main ()
+	{
+		_ = Main ();
+	}
+}
\ No newline at end of file
diff --git a/mcs/errors/cs8323.cs b/mcs/errors/cs8323.cs
new file mode 100644
index 00000000000..c6c9309ec0d
--- /dev/null
+++ b/mcs/errors/cs8323.cs
@@ -0,0 +1,15 @@
+// CS8323: Named argument `str' is used out of position but is followed by positional argument
+// Line: 9
+// Compiler options: -langversion:7.2
+
+class X
+{
+	public static void Main ()
+	{
+		Test (str: "", "");
+	}
+
+	static void Test (int arg, string str)
+	{
+	}
+}
\ No newline at end of file
diff --git a/mcs/errors/cs8324.cs b/mcs/errors/cs8324.cs
new file mode 100644
index 00000000000..8a0be1aefb9
--- /dev/null
+++ b/mcs/errors/cs8324.cs
@@ -0,0 +1,12 @@
+// CS8324: Named argument specifications must appear after all fixed arguments have been specified in a dynamic invocation
+// Line: 10
+// Compiler options: -langversion:7.2
+
+class C
+{
+	void M ()
+	{
+		dynamic d = new object ();
+		d.M (arg: 1, "");
+	}
+}
\ No newline at end of file