Add void_t and invoke feature test macros

llvm-svn: 284209

1 files changed, 39 insertions, 0 deletions

diff --git a/libcxx/test/std/utilities/function.objects/func.invoke/invoke_feature_test_macro.pass.cpp b/libcxx/test/std/utilities/function.objects/func.invoke/invoke_feature_test_macro.pass.cpp
new file mode 100644
index 00000000000..aaac98474fc
--- /dev/null
+++ b/libcxx/test/std/utilities/function.objects/func.invoke/invoke_feature_test_macro.pass.cpp
@@ -0,0 +1,39 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <functional>
+
+// template <class F, class ...Args>
+// result_of_t<F&&(Args&&...)> invoke(F&&, Args&&...);
+
+#include <functional>
+#include <cassert>
+
+#include "test_macros.h"
+
+#if TEST_STD_VER <= 14
+# ifdef __cpp_lib_invoke
+#   error Feature test macro should be defined
+# endif
+#else
+# ifndef __cpp_lib_invoke
+#   error Feature test macro not defined
+# endif
+# if __cpp_lib_invoke != 201411
+#   error __cpp_lib_invoke has the wrong value
+# endif
+#endif
+
+int foo(int) { return 42; }
+
+int main() {
+#if defined(__cpp_lib_invoke)
+  assert(std::invoke(foo, 101) == 42);
+#endif
+}
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