Fixes for C++20 support when not using std::optional.
* Avoid warnings due to deprecation of volatile return types.
Also fix up optional_test.cc due to ABSL_USES_STD_OPTIONAL always being
false in its body.
Bug: chromium:1284275
PiperOrigin-RevId: 447796238
Change-Id: If050206c979c6c08af22e71ff0ea91e7f7932f0c
diff --git a/absl/types/optional_test.cc b/absl/types/optional_test.cc
index 1846e69..9477c15 100644
--- a/absl/types/optional_test.cc
+++ b/absl/types/optional_test.cc
@@ -27,6 +27,11 @@
#include "absl/meta/type_traits.h"
#include "absl/strings/string_view.h"
+#if defined(__cplusplus) && __cplusplus >= 202002L
+// In C++20, volatile-qualified return types are deprecated.
+#define ABSL_VOLATILE_RETURN_TYPES_DEPRECATED 1
+#endif
+
// The following types help test an internal compiler error in GCC5 though
// GCC10. The case OptionalTest.InternalCompilerErrorInGcc5ToGcc10 crashes the
// compiler without a workaround. This test case should remain at the beginning
@@ -231,6 +236,7 @@
EXPECT_TRUE(opt42_copy);
EXPECT_EQ(42, *opt42_copy);
}
+#if !defined(ABSL_VOLATILE_RETURN_TYPES_DEPRECATED)
{
absl::optional<volatile int> empty, opt42 = 42;
absl::optional<volatile int> empty_copy(empty);
@@ -239,6 +245,7 @@
EXPECT_TRUE(opt42_copy);
EXPECT_EQ(42, *opt42_copy);
}
+#endif
// test copyablility
EXPECT_TRUE(std::is_copy_constructible<absl::optional<int>>::value);
EXPECT_TRUE(std::is_copy_constructible<absl::optional<Copyable>>::value);
@@ -250,18 +257,11 @@
EXPECT_FALSE(
absl::is_trivially_copy_constructible<absl::optional<Copyable>>::value);
-#if defined(ABSL_USES_STD_OPTIONAL) && defined(__GLIBCXX__)
- // libstdc++ std::optional implementation (as of 7.2) has a bug: when T is
- // trivially copyable, optional<T> is not trivially copyable (due to one of
- // its base class is unconditionally nontrivial).
-#define ABSL_GLIBCXX_OPTIONAL_TRIVIALITY_BUG 1
-#endif
-#ifndef ABSL_GLIBCXX_OPTIONAL_TRIVIALITY_BUG
EXPECT_TRUE(
absl::is_trivially_copy_constructible<absl::optional<int>>::value);
EXPECT_TRUE(
absl::is_trivially_copy_constructible<absl::optional<const int>>::value);
-#ifndef _MSC_VER
+#if !defined(_MSC_VER) && !defined(ABSL_VOLATILE_RETURN_TYPES_DEPRECATED)
// See defect report "Trivial copy/move constructor for class with volatile
// member" at
// http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#2094
@@ -270,8 +270,7 @@
// Also a cv-qualified scalar type should be trivially copyable.
EXPECT_TRUE(absl::is_trivially_copy_constructible<
absl::optional<volatile int>>::value);
-#endif // _MSC_VER
-#endif // ABSL_GLIBCXX_OPTIONAL_TRIVIALITY_BUG
+#endif // !defined(_MSC_VER) && !defined(ABSL_VOLATILE_RETURN_TYPES_DEPRECATED)
// constexpr copy constructor for trivially copyable types
{
@@ -301,17 +300,10 @@
EXPECT_TRUE(absl::is_trivially_copy_constructible<
absl::optional<const TrivialCopyable>>::value);
#endif
- // When testing with VS 2017 15.3, there seems to be a bug in MSVC
- // std::optional when T is volatile-qualified. So skipping this test.
- // Bug report:
- // https://connect.microsoft.com/VisualStudio/feedback/details/3142534
-#if defined(ABSL_USES_STD_OPTIONAL) && defined(_MSC_VER) && _MSC_VER >= 1911
-#define ABSL_MSVC_OPTIONAL_VOLATILE_COPY_BUG 1
-#endif
-#ifndef ABSL_MSVC_OPTIONAL_VOLATILE_COPY_BUG
+#if !defined(ABSL_VOLATILE_RETURN_TYPES_DEPRECATED)
EXPECT_FALSE(std::is_copy_constructible<
absl::optional<volatile TrivialCopyable>>::value);
-#endif
+#endif // !defined(ABSL_VOLATILE_RETURN_TYPES_DEPRECATED)
}
}
@@ -331,11 +323,9 @@
EXPECT_FALSE(std::is_move_constructible<absl::optional<NonMovable>>::value);
// test noexcept
EXPECT_TRUE(std::is_nothrow_move_constructible<absl::optional<int>>::value);
-#ifndef ABSL_USES_STD_OPTIONAL
EXPECT_EQ(
absl::default_allocator_is_nothrow::value,
std::is_nothrow_move_constructible<absl::optional<MoveableThrow>>::value);
-#endif
EXPECT_TRUE(std::is_nothrow_move_constructible<
absl::optional<MoveableNoThrow>>::value);
}
@@ -664,8 +654,7 @@
EXPECT_TRUE(absl::is_copy_assignable<NonTrivial>::value);
EXPECT_FALSE(absl::is_trivially_copy_assignable<NonTrivial>::value);
- // std::optional doesn't support volatile nontrivial types.
-#ifndef ABSL_USES_STD_OPTIONAL
+#if !defined(ABSL_VOLATILE_RETURN_TYPES_DEPRECATED)
{
StructorListener listener;
Listenable::listener = &listener;
@@ -684,7 +673,7 @@
EXPECT_EQ(1, listener.destruct);
EXPECT_EQ(1, listener.volatile_copy_assign);
}
-#endif // ABSL_USES_STD_OPTIONAL
+#endif // !defined(ABSL_VOLATILE_RETURN_TYPES_DEPRECATED)
}
TEST(optionalTest, MoveAssignment) {
@@ -707,8 +696,7 @@
EXPECT_EQ(1, listener.destruct);
EXPECT_EQ(1, listener.move_assign);
}
- // std::optional doesn't support volatile nontrivial types.
-#ifndef ABSL_USES_STD_OPTIONAL
+#if !defined(ABSL_VOLATILE_RETURN_TYPES_DEPRECATED)
{
StructorListener listener;
Listenable::listener = &listener;
@@ -728,7 +716,7 @@
EXPECT_EQ(1, listener.destruct);
EXPECT_EQ(1, listener.volatile_move_assign);
}
-#endif // ABSL_USES_STD_OPTIONAL
+#endif // !defined(ABSL_VOLATILE_RETURN_TYPES_DEPRECATED)
EXPECT_FALSE(absl::is_move_assignable<absl::optional<const int>>::value);
EXPECT_TRUE(absl::is_move_assignable<absl::optional<Copyable>>::value);
EXPECT_TRUE(absl::is_move_assignable<absl::optional<MoveableThrow>>::value);
@@ -1064,6 +1052,7 @@
#endif
EXPECT_EQ("c&&", TypeQuals(OC(absl::in_place, "xvalue_c").value()));
+#if !defined(ABSL_VOLATILE_RETURN_TYPES_DEPRECATED)
// test on volatile type
using OV = absl::optional<volatile int>;
OV lvalue_v(absl::in_place, 42);
@@ -1071,6 +1060,7 @@
EXPECT_EQ(42, OV(42).value());
EXPECT_TRUE((std::is_same<volatile int&, decltype(lvalue_v.value())>::value));
EXPECT_TRUE((std::is_same<volatile int&&, decltype(OV(42).value())>::value));
+#endif // !defined(ABSL_VOLATILE_RETURN_TYPES_DEPRECATED)
// test exception throw on value()
absl::optional<int> empty;
@@ -1113,6 +1103,7 @@
#endif
EXPECT_EQ("c&&", TypeQuals(*OC(absl::in_place, "xvalue_c")));
+#if !defined(ABSL_VOLATILE_RETURN_TYPES_DEPRECATED)
// test on volatile type
using OV = absl::optional<volatile int>;
OV lvalue_v(absl::in_place, 42);
@@ -1120,6 +1111,7 @@
EXPECT_EQ(42, *OV(42));
EXPECT_TRUE((std::is_same<volatile int&, decltype(*lvalue_v)>::value));
EXPECT_TRUE((std::is_same<volatile int&&, decltype(*OV(42))>::value));
+#endif // !defined(ABSL_VOLATILE_RETURN_TYPES_DEPRECATED)
constexpr absl::optional<int> opt1(1);
static_assert(*opt1 == 1, "");
@@ -1584,12 +1576,10 @@
static_assert(
std::is_nothrow_move_constructible<absl::optional<MoveMeNoThrow>>::value,
"");
-#ifndef ABSL_USES_STD_OPTIONAL
static_assert(absl::default_allocator_is_nothrow::value ==
std::is_nothrow_move_constructible<
absl::optional<MoveMeThrow>>::value,
"");
-#endif
std::vector<absl::optional<MoveMeNoThrow>> v;
for (int i = 0; i < 10; ++i) v.emplace_back();
}
