Support runtime check of function types.

tests/language/function_subtype_bound_closure2_test.dart

+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+// Dart test program for constructors and initializers.
+
+// Check function subtyping for bound closures on generic type against generic
+// typedefs.
+
+import 'package:expect/expect.dart';
+
+typedef int Foo<T>(T a, [String b]);
+typedef int Bar<T>(T a, [String b]);
+typedef int Baz<T>(T a, {String b});
+typedef int Boz<T>(T a);
+typedef int Biz<T>(T a, int b);
+
+class C<T> {
+  int foo(bool a, [String b]) => null;
+  int baz(bool a, {String b}) => null;
+
+  void test(String nameOfT, bool expectedResult) {
+    Expect.equals(expectedResult, foo is Foo<T>, 'foo is Foo<$nameOfT>');
+    Expect.equals(expectedResult, foo is Bar<T>, 'foo is Bar<$nameOfT>');
+    Expect.isFalse(foo is Baz<T>, 'foo is Baz<$nameOfT>');
+    Expect.equals(expectedResult, foo is Boz<T>, 'foo is Boz<$nameOfT>');
+    Expect.isFalse(foo is Biz<T>, 'foo is Biz<$nameOfT>');
+
+    Expect.isFalse(baz is Foo<T>, 'baz is Foo<$nameOfT>');
+    Expect.isFalse(baz is Bar<T>, 'baz is Bar<$nameOfT>');
+    Expect.equals(expectedResult, baz is Baz<T>, 'baz is Baz<$nameOfT>');
+    Expect.equals(expectedResult, baz is Boz<T>, 'baz is Boz<$nameOfT>');
+    Expect.isFalse(baz is Biz<T>, 'bar is Biz<$nameOfT>');
+  }
+}
+
+main() {
+  new C<bool>().test('bool', true);
+  new C<int>().test('int', false);
+  new C().test('dynamic', true);
+}