1 files changed, 71 insertions, 0 deletions
diff --git a/libcxx/test/libcxx/utilities/expected/expected.void/error_or.mandates.verify.cpp b/libcxx/test/libcxx/utilities/expected/expected.void/error_or.mandates.verify.cpp
new file mode 100644
index 000000000000..a36665b25c87
--- /dev/null
+++ b/libcxx/test/libcxx/utilities/expected/expected.void/error_or.mandates.verify.cpp
@@ -0,0 +1,71 @@
+//===----------------------------------------------------------------------===//
+//
+// 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++03, c++11, c++14, c++17, c++20
+
+// Test the mandates
+// template<class G = E> constexpr E error_or(G&&) const &;
+// Mandates: is_copy_constructible_v<G> is true and is_convertible_v<U, E> is true.
+
+// template<class G = E> constexpr E error_or(G&&) &&;
+// Mandates: is_move_constructible_v<G> is true and is_convertible_v<U, E> is true.
+
+#include <expected>
+#include <utility>
+
+struct NonCopyable {
+  NonCopyable(int) {}
+  NonCopyable(const NonCopyable&) = delete;
+};
+
+struct NonMovable {
+  NonMovable(int) {}
+  NonMovable(NonMovable&&) = delete;
+};
+
+struct NotConvertibleFromInt {};
+
+// clang-format off
+void test() {
+  // const & overload
+  // !is_copy_constructible_v<G>,
+  {
+    const std::expected<void, NonCopyable> f1(std::unexpect, 0);
+    f1.error_or(5); // expected-note{{in instantiation of function template specialization 'std::expected<void, NonCopyable>::error_or<int>' requested here}}
+    // expected-error-re@*:* {{{{(static_assert|static assertion)}} failed {{.*}}error_type has to be copy constructible}}
+    // expected-error-re@*:* {{call to deleted constructor of{{.*}}}}
+  }
+
+  // const & overload
+  // !is_convertible_v<U, T>
+  {
+    const std::expected<void, NotConvertibleFromInt> f1(std::unexpect, NotConvertibleFromInt{});
+    f1.error_or(5); // expected-note{{in instantiation of function template specialization 'std::expected<void, NotConvertibleFromInt>::error_or<int>' requested here}}
+    // expected-error-re@*:* {{{{(static_assert|static assertion)}} failed {{.*}}argument has to be convertible to error_type}}
+    // expected-error-re@*:* {{no viable conversion from returned value of type{{.*}}}}
+  }
+
+  // && overload
+  // !is_move_constructible_v<T>,
+  {
+    std::expected<void, NonMovable> f1(std::unexpect, 0);
+    std::move(f1).error_or(5); // expected-note{{in instantiation of function template specialization 'std::expected<void, NonMovable>::error_or<int>' requested here}}
+    // expected-error-re@*:* {{{{(static_assert|static assertion)}} failed {{.*}}error_type has to be move constructible}}
+    // expected-error-re@*:* {{call to deleted constructor of{{.*}}}}
+  }
+
+  // && overload
+  // !is_convertible_v<U, T>
+  {
+    std::expected<void, NotConvertibleFromInt> f1(std::unexpect, NotConvertibleFromInt{});
+    std::move(f1).error_or(5); // expected-note{{in instantiation of function template specialization 'std::expected<void, NotConvertibleFromInt>::error_or<int>' requested here}}
+    // expected-error-re@*:* {{{{(static_assert|static assertion)}} failed {{.*}}argument has to be convertible to error_type}}
+    // expected-error-re@*:* {{no viable conversion from returned value of type{{.*}}}}
+  }
+}
+// clang-format on