2 files changed, 79 insertions, 0 deletions
diff --git a/libcxx/test/std/utilities/meta/meta.const.eval/is_constant_evaluated.fail.cpp b/libcxx/test/std/utilities/meta/meta.const.eval/is_constant_evaluated.fail.cpp
new file mode 100644
index 00000000000..c139233b8da
--- /dev/null
+++ b/libcxx/test/std/utilities/meta/meta.const.eval/is_constant_evaluated.fail.cpp
@@ -0,0 +1,29 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03
+
+// <type_traits>
+
+
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+
+int main(int, char**)
+{
+#ifndef __cpp_lib_is_constant_evaluated
+  // expected-error@+1 {{no member named 'is_constant_evaluated' in namespace 'std'}}
+  bool b = std::is_constant_evaluated();
+#else
+  // expected-error@+1 {{static_assert failed}}
+  static_assert(!std::is_constant_evaluated(), "");
+#endif
+  return 0;
+}
diff --git a/libcxx/test/std/utilities/meta/meta.const.eval/is_constant_evaluated.pass.cpp b/libcxx/test/std/utilities/meta/meta.const.eval/is_constant_evaluated.pass.cpp
new file mode 100644
index 00000000000..4dc796e950f
--- /dev/null
+++ b/libcxx/test/std/utilities/meta/meta.const.eval/is_constant_evaluated.pass.cpp
@@ -0,0 +1,50 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+
+// <type_traits>
+
+// constexpr bool is_constant_evaluated() noexcept; // C++20
+
+#include <type_traits>
+#include <cassert>
+
+#include "test_macros.h"
+
+#ifndef __cpp_lib_is_constant_evaluated
+#if TEST_HAS_BUILTIN(__builtin_is_constant_evaluated)
+# error __cpp_lib_is_constant_evaluated should be defined
+#endif
+#endif
+
+template <bool> struct InTemplate {};
+
+int main(int, char**)
+{
+#ifdef __cpp_lib_is_constant_evaluated
+  // Test the signature
+  {
+    ASSERT_SAME_TYPE(decltype(std::is_constant_evaluated()), bool);
+    ASSERT_NOEXCEPT(std::is_constant_evaluated());
+    constexpr bool p = std::is_constant_evaluated();
+    assert(p);
+  }
+  // Test the return value of the builtin for basic sanity only. It's the
+  // compilers job to test tho builtin for correctness.
+  {
+    static_assert(std::is_constant_evaluated(), "");
+    bool p = std::is_constant_evaluated();
+    assert(!p);
+    ASSERT_SAME_TYPE(InTemplate<std::is_constant_evaluated()>, InTemplate<true>);
+    static int local_static = std::is_constant_evaluated() ? 42 : -1;
+    assert(local_static == 42);
+  }
+#endif
+  return 0;
+}