[libcxx] Reorganize tests since the application of P0602R4

Summary:
P0602R4 makes the special member functions of optional and variant
conditionally trivial based on the types in the optional/variant.
We already implemented that, but the tests were organized as if this
were a non-standard extension. This patch reorganizes the tests in a
way that makes more sense since this is not an extension anymore.

Reviewers: EricWF, mpark, mclow.lists

Subscribers: christof, jkorous, dexonsmith, libcxx-commits

Differential Revision: https://reviews.llvm.org/D54772

llvm-svn: 350884

6 files changed, 201 insertions, 141 deletions

diff --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/copy.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/copy.pass.cpp
index 98c90aa1d4f..bec0f09a3e9 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/copy.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/copy.pass.cpp
@@ -10,7 +10,7 @@
 // UNSUPPORTED: c++98, c++03, c++11, c++14
 // <optional>
 
-// optional<T>& operator=(const optional<T>& rhs);
+// optional<T>& operator=(const optional<T>& rhs); // constexpr in C++20
 
 #include <optional>
 #include <type_traits>
@@ -53,15 +53,19 @@ int main()
 {
     {
         using O = optional<int>;
+#if TEST_STD_VER > 17
         LIBCPP_STATIC_ASSERT(assign_empty(O{42}), "");
         LIBCPP_STATIC_ASSERT(assign_value(O{42}), "");
+#endif
         assert(assign_empty(O{42}));
         assert(assign_value(O{42}));
     }
     {
         using O = optional<TrivialTestTypes::TestType>;
+#if TEST_STD_VER > 17
         LIBCPP_STATIC_ASSERT(assign_empty(O{42}), "");
         LIBCPP_STATIC_ASSERT(assign_value(O{42}), "");
+#endif
         assert(assign_empty(O{42}));
         assert(assign_value(O{42}));
     }
diff --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/move.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/move.pass.cpp
index ed8b433da69..c41674f13cf 100644
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/move.pass.cpp
+++ b/libcxx/test/std/utilities/optional/optional.object/optional.object.assign/move.pass.cpp
@@ -12,11 +12,12 @@
 
 // optional<T>& operator=(optional<T>&& rhs)
 //     noexcept(is_nothrow_move_assignable<T>::value &&
-//              is_nothrow_move_constructible<T>::value);
+//              is_nothrow_move_constructible<T>::value); // constexpr in C++20
 
 #include <optional>
-#include <type_traits>
 #include <cassert>
+#include <type_traits>
+#include <utility>
 
 #include "test_macros.h"
 #include "archetypes.hpp"
@@ -51,6 +52,21 @@ struct Y {};
 bool X::throw_now = false;
 int X::alive = 0;
 
+
+template <class Tp>
+constexpr bool assign_empty(optional<Tp>&& lhs) {
+    optional<Tp> rhs;
+    lhs = std::move(rhs);
+    return !lhs.has_value() && !rhs.has_value();
+}
+
+template <class Tp>
+constexpr bool assign_value(optional<Tp>&& lhs) {
+    optional<Tp> rhs(101);
+    lhs = std::move(rhs);
+    return lhs.has_value() && rhs.has_value() && *lhs == Tp{101};
+}
+
 int main()
 {
     {
@@ -97,6 +113,24 @@ int main()
         assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
         assert(*opt == *opt2);
     }
+    {
+        using O = optional<int>;
+#if TEST_STD_VER > 17
+        LIBCPP_STATIC_ASSERT(assign_empty(O{42}), "");
+        LIBCPP_STATIC_ASSERT(assign_value(O{42}), "");
+#endif
+        assert(assign_empty(O{42}));
+        assert(assign_value(O{42}));
+    }
+    {
+        using O = optional<TrivialTestTypes::TestType>;
+#if TEST_STD_VER > 17
+        LIBCPP_STATIC_ASSERT(assign_empty(O{42}), "");
+        LIBCPP_STATIC_ASSERT(assign_value(O{42}), "");
+#endif
+        assert(assign_empty(O{42}));
+        assert(assign_value(O{42}));
+    }
 #ifndef TEST_HAS_NO_EXCEPTIONS
     {
         static_assert(!std::is_nothrow_move_assignable<optional<X>>::value, "");
diff --git a/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/copy.fail.cpp b/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/copy.fail.cpp
deleted file mode 100644
index 5933683487a..00000000000
--- a/libcxx/test/std/utilities/optional/optional.object/optional.object.ctor/copy.fail.cpp
+++ /dev/null
@@ -1,36 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-//                     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.
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++98, c++03, c++11, c++14
-// <optional>
-
-// constexpr optional(const optional<T>& rhs);
-//   If is_trivially_copy_constructible_v<T> is true,
-//    this constructor shall be a constexpr constructor.
-
-#include <optional>
-#include <type_traits>
-#include <cassert>
-
-#include "test_macros.h"
-
-struct S {
-    constexpr S()   : v_(0) {}
-    S(int v)        : v_(v) {}
-    S(const S &rhs) : v_(rhs.v_) {}  // make it not trivially copyable
-    int v_;
-};
-
-
-int main()
-{
-    static_assert (!std::is_trivially_copy_constructible_v<S>, "" );
-    constexpr std::optional<S> o1;
-    constexpr std::optional<S> o2 = o1;  // not constexpr
-}
diff --git a/libcxx/test/std/utilities/optional/optional.object/special_member_gen.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/special_member_gen.pass.cpp
deleted file mode 100644
index 0b9b6e717c3..00000000000
--- a/libcxx/test/std/utilities/optional/optional.object/special_member_gen.pass.cpp
+++ /dev/null
@@ -1,102 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-//                     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.
-//
-//===----------------------------------------------------------------------===//
-
-// UNSUPPORTED: c++98, c++03, c++11, c++14
-// <optional>
-
-
-#include <optional>
-#include <type_traits>
-#include <cassert>
-
-#include "archetypes.hpp"
-
-template <class T>
-struct SpecialMemberTest {
-    using O = std::optional<T>;
-
-    static_assert(std::is_default_constructible_v<O>,
-        "optional is always default constructible.");
-    static_assert(std::is_copy_constructible_v<O> == std::is_copy_constructible_v<T>,
-        "optional<T> is copy constructible if and only if T is copy constructible.");
-    static_assert(std::is_move_constructible_v<O> ==
-        (std::is_copy_constructible_v<T> || std::is_move_constructible_v<T>),
-        "optional<T> is move constructible if and only if T is copy or move constructible.");
-    static_assert(std::is_copy_assignable_v<O> ==
-        (std::is_copy_constructible_v<T> && std::is_copy_assignable_v<T>),
-        "optional<T> is copy assignable if and only if T is both copy "
-        "constructible and copy assignable.");
-    static_assert(std::is_move_assignable_v<O> ==
-        ((std::is_move_constructible_v<T> && std::is_move_assignable_v<T>) ||
-         (std::is_copy_constructible_v<T> && std::is_copy_assignable_v<T>)),
-        "optional<T> is move assignable if and only if T is both move constructible and "
-        "move assignable, or both copy constructible and copy assignable.");
-
-    // The following tests are for not-yet-standardized behavior (P0602):
-    static_assert(std::is_trivially_destructible_v<O> ==
-        std::is_trivially_destructible_v<T>,
-        "optional<T> is trivially destructible if and only if T is.");
-    static_assert(std::is_trivially_copy_constructible_v<O> ==
-        std::is_trivially_copy_constructible_v<T>,
-        "optional<T> is trivially copy constructible if and only if T is.");
-    static_assert(std::is_trivially_move_constructible_v<O> ==
-        std::is_trivially_move_constructible_v<T> ||
-        (!std::is_move_constructible_v<T> && std::is_trivially_copy_constructible_v<T>),
-        "optional<T> is trivially move constructible if T is trivially move constructible, "
-        "or if T is trivially copy constructible and is not move constructible.");
-    static_assert(std::is_trivially_copy_assignable_v<O> ==
-        (std::is_trivially_destructible_v<T> &&
-         std::is_trivially_copy_constructible_v<T> &&
-         std::is_trivially_copy_assignable_v<T>),
-        "optional<T> is trivially copy assignable if and only if T is trivially destructible, "
-        "trivially copy constructible, and trivially copy assignable.");
-    static_assert(std::is_trivially_move_assignable_v<O> ==
-        (std::is_trivially_destructible_v<T> &&
-         ((std::is_trivially_move_constructible_v<T> && std::is_trivially_move_assignable_v<T>) ||
-          ((!std::is_move_constructible_v<T> || !std::is_move_assignable_v<T>) &&
-           std::is_trivially_copy_constructible_v<T> && std::is_trivially_copy_assignable_v<T>))),
-        "optional<T> is trivially move assignable if T is trivially destructible, and either "
-        "(1) trivially move constructible and trivially move assignable, or "
-        "(2) not move constructible or not move assignable, and "
-        "trivially copy constructible and trivially copy assignable.");
-};
-
-template <class ...Args> static void sink(Args&&...) {}
-
-template <class ...TestTypes>
-struct DoTestsMetafunction {
-    DoTestsMetafunction() { sink(SpecialMemberTest<TestTypes>{}...); }
-};
-
-struct TrivialMoveNonTrivialCopy {
-    TrivialMoveNonTrivialCopy() = default;
-    TrivialMoveNonTrivialCopy(const TrivialMoveNonTrivialCopy&) {}
-    TrivialMoveNonTrivialCopy(TrivialMoveNonTrivialCopy&&) = default;
-    TrivialMoveNonTrivialCopy& operator=(const TrivialMoveNonTrivialCopy&) { return *this; }
-    TrivialMoveNonTrivialCopy& operator=(TrivialMoveNonTrivialCopy&&) = default;
-};
-
-struct TrivialCopyNonTrivialMove {
-    TrivialCopyNonTrivialMove() = default;
-    TrivialCopyNonTrivialMove(const TrivialCopyNonTrivialMove&) = default;
-    TrivialCopyNonTrivialMove(TrivialCopyNonTrivialMove&&) {}
-    TrivialCopyNonTrivialMove& operator=(const TrivialCopyNonTrivialMove&) = default;
-    TrivialCopyNonTrivialMove& operator=(TrivialCopyNonTrivialMove&&) { return *this; }
-};
-
-int main()
-{
-    sink(
-        ImplicitTypes::ApplyTypes<DoTestsMetafunction>{},
-        ExplicitTypes::ApplyTypes<DoTestsMetafunction>{},
-        NonLiteralTypes::ApplyTypes<DoTestsMetafunction>{},
-        NonTrivialTypes::ApplyTypes<DoTestsMetafunction>{},
-        DoTestsMetafunction<TrivialMoveNonTrivialCopy, TrivialCopyNonTrivialMove>{}
-    );
-}
diff --git a/libcxx/test/std/utilities/optional/optional.object/special_members.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/special_members.pass.cpp
new file mode 100644
index 00000000000..3bc561cfea3
--- /dev/null
+++ b/libcxx/test/std/utilities/optional/optional.object/special_members.pass.cpp
@@ -0,0 +1,63 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14
+
+// <optional>
+
+// Make sure we properly generate special member functions for optional<T>
+// based on the properties of T itself.
+
+#include <optional>
+#include <type_traits>
+
+#include "archetypes.hpp"
+
+
+template <class T>
+struct SpecialMemberTest {
+    using O = std::optional<T>;
+
+    static_assert(std::is_default_constructible_v<O>,
+        "optional is always default constructible.");
+
+    static_assert(std::is_copy_constructible_v<O> == std::is_copy_constructible_v<T>,
+        "optional<T> is copy constructible if and only if T is copy constructible.");
+
+    static_assert(std::is_move_constructible_v<O> ==
+        (std::is_copy_constructible_v<T> || std::is_move_constructible_v<T>),
+        "optional<T> is move constructible if and only if T is copy or move constructible.");
+
+    static_assert(std::is_copy_assignable_v<O> ==
+        (std::is_copy_constructible_v<T> && std::is_copy_assignable_v<T>),
+        "optional<T> is copy assignable if and only if T is both copy "
+        "constructible and copy assignable.");
+
+    static_assert(std::is_move_assignable_v<O> ==
+        ((std::is_move_constructible_v<T> && std::is_move_assignable_v<T>) ||
+         (std::is_copy_constructible_v<T> && std::is_copy_assignable_v<T>)),
+        "optional<T> is move assignable if and only if T is both move constructible and "
+        "move assignable, or both copy constructible and copy assignable.");
+};
+
+template <class ...Args> static void sink(Args&&...) {}
+
+template <class ...TestTypes>
+struct DoTestsMetafunction {
+    DoTestsMetafunction() { sink(SpecialMemberTest<TestTypes>{}...); }
+};
+
+int main() {
+    sink(
+        ImplicitTypes::ApplyTypes<DoTestsMetafunction>{},
+        ExplicitTypes::ApplyTypes<DoTestsMetafunction>{},
+        NonLiteralTypes::ApplyTypes<DoTestsMetafunction>{},
+        NonTrivialTypes::ApplyTypes<DoTestsMetafunction>{}
+    );
+}
diff --git a/libcxx/test/std/utilities/optional/optional.object/triviality.pass.cpp b/libcxx/test/std/utilities/optional/optional.object/triviality.pass.cpp
new file mode 100644
index 00000000000..c21c85aad96
--- /dev/null
+++ b/libcxx/test/std/utilities/optional/optional.object/triviality.pass.cpp
@@ -0,0 +1,97 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+
+// <optional>
+
+// The following special member functions should propagate the triviality of
+// the element held in the optional (see P0602R4):
+//
+// constexpr optional(const optional& rhs);
+// constexpr optional(optional&& rhs) noexcept(see below);
+// constexpr optional<T>& operator=(const optional& rhs);
+// constexpr optional<T>& operator=(optional&& rhs) noexcept(see below);
+
+
+#include <optional>
+#include <type_traits>
+
+#include "archetypes.hpp"
+
+
+constexpr bool implies(bool p, bool q) {
+    return !p || q;
+}
+
+template <class T>
+struct SpecialMemberTest {
+    using O = std::optional<T>;
+
+    static_assert(implies(std::is_trivially_copy_constructible_v<T>,
+                          std::is_trivially_copy_constructible_v<O>),
+        "optional<T> is trivially copy constructible if T is trivially copy constructible.");
+
+    static_assert(implies(std::is_trivially_move_constructible_v<T>,
+                          std::is_trivially_move_constructible_v<O>),
+        "optional<T> is trivially move constructible if T is trivially move constructible");
+
+    static_assert(implies(std::is_trivially_copy_constructible_v<T> &&
+                          std::is_trivially_copy_assignable_v<T> &&
+                          std::is_trivially_destructible_v<T>,
+
+                          std::is_trivially_copy_assignable_v<O>),
+        "optional<T> is trivially copy assignable if T is "
+        "trivially copy constructible, "
+        "trivially copy assignable, and "
+        "trivially destructible");
+
+    static_assert(implies(std::is_trivially_move_constructible_v<T> &&
+                          std::is_trivially_move_assignable_v<T> &&
+                          std::is_trivially_destructible_v<T>,
+
+                          std::is_trivially_move_assignable_v<O>),
+        "optional<T> is trivially move assignable if T is "
+        "trivially move constructible, "
+        "trivially move assignable, and"
+        "trivially destructible.");
+};
+
+template <class ...Args> static void sink(Args&&...) {}
+
+template <class ...TestTypes>
+struct DoTestsMetafunction {
+    DoTestsMetafunction() { sink(SpecialMemberTest<TestTypes>{}...); }
+};
+
+struct TrivialMoveNonTrivialCopy {
+    TrivialMoveNonTrivialCopy() = default;
+    TrivialMoveNonTrivialCopy(const TrivialMoveNonTrivialCopy&) {}
+    TrivialMoveNonTrivialCopy(TrivialMoveNonTrivialCopy&&) = default;
+    TrivialMoveNonTrivialCopy& operator=(const TrivialMoveNonTrivialCopy&) { return *this; }
+    TrivialMoveNonTrivialCopy& operator=(TrivialMoveNonTrivialCopy&&) = default;
+};
+
+struct TrivialCopyNonTrivialMove {
+    TrivialCopyNonTrivialMove() = default;
+    TrivialCopyNonTrivialMove(const TrivialCopyNonTrivialMove&) = default;
+    TrivialCopyNonTrivialMove(TrivialCopyNonTrivialMove&&) {}
+    TrivialCopyNonTrivialMove& operator=(const TrivialCopyNonTrivialMove&) = default;
+    TrivialCopyNonTrivialMove& operator=(TrivialCopyNonTrivialMove&&) { return *this; }
+};
+
+int main() {
+    sink(
+        ImplicitTypes::ApplyTypes<DoTestsMetafunction>{},
+        ExplicitTypes::ApplyTypes<DoTestsMetafunction>{},
+        NonLiteralTypes::ApplyTypes<DoTestsMetafunction>{},
+        NonTrivialTypes::ApplyTypes<DoTestsMetafunction>{},
+        DoTestsMetafunction<TrivialMoveNonTrivialCopy, TrivialCopyNonTrivialMove>{}
+    );
+}