加所有权之前

2026-08-28 12:14:15 +08:00
parent 81d3d50966
commit 0bc281b6b9
86 changed files with 12167 additions and 427 deletions
@@ -0,0 +1,119 @@
+#include <gtest/gtest.h>
+
+#include <gsl/pointers>
+
+#include <functional>
+#include <memory>
+#include <type_traits>
+#include <utility>
+
+#if __cplusplus >= 201703l
+using std::void_t;
+#else  // __cplusplus >= 201703l
+template <class...>
+using void_t = void;
+#endif // __cplusplus < 201703l
+
+namespace
+{
+// Custom pointer type that can be used for gsl::not_null, but for which these cannot be swapped.
+struct NotMoveAssignableCustomPtr
+{
+    NotMoveAssignableCustomPtr() = default;
+    NotMoveAssignableCustomPtr(const NotMoveAssignableCustomPtr&) = default;
+    NotMoveAssignableCustomPtr& operator=(const NotMoveAssignableCustomPtr&) = default;
+    NotMoveAssignableCustomPtr(NotMoveAssignableCustomPtr&&) = default;
+    NotMoveAssignableCustomPtr& operator=(NotMoveAssignableCustomPtr&&) = delete;
+
+    bool operator!=(std::nullptr_t) const { return true; }
+
+    int dummy{}; // Without this clang warns, that NotMoveAssignableCustomPtr() is unneeded
+};
+
+template <typename U, typename = void>
+static constexpr bool SwapCompilesFor = false;
+template <typename U>
+static constexpr bool
+    SwapCompilesFor<U, void_t<decltype(gsl::swap<U>(std::declval<gsl::not_null<U>&>(),
+                                                    std::declval<gsl::not_null<U>&>()))>> = true;
+
+TEST(pointers_test, swap)
+{
+    // taken from gh-1129:
+    {
+        gsl::not_null<std::unique_ptr<int>> a(std::make_unique<int>(0));
+        gsl::not_null<std::unique_ptr<int>> b(std::make_unique<int>(1));
+
+        static_assert(noexcept(gsl::swap(a, b)),
+                      "not null unique_ptr should be noexcept-swappable");
+
+        EXPECT_TRUE(*a == 0);
+        EXPECT_TRUE(*b == 1);
+
+        gsl::swap(a, b);
+
+        EXPECT_TRUE(*a == 1);
+        EXPECT_TRUE(*b == 0);
+
+        // Make sure our custom ptr can be used with not_null. The shared_pr is to prevent "unused"
+        // compiler warnings.
+        const auto shared_custom_ptr{std::make_shared<NotMoveAssignableCustomPtr>()};
+        gsl::not_null<NotMoveAssignableCustomPtr> c{*shared_custom_ptr};
+        EXPECT_TRUE(c.get() != nullptr);
+    }
+
+    {
+        gsl::strict_not_null<std::unique_ptr<int>> a{std::make_unique<int>(0)};
+        gsl::strict_not_null<std::unique_ptr<int>> b{std::make_unique<int>(1)};
+
+        static_assert(noexcept(gsl::swap(a, b)),
+                      "strict not null unique_ptr should be noexcept-swappable");
+
+        EXPECT_TRUE(*a == 0);
+        EXPECT_TRUE(*b == 1);
+
+        gsl::swap(a, b);
+
+        EXPECT_TRUE(*a == 1);
+        EXPECT_TRUE(*b == 0);
+    }
+
+    {
+        gsl::not_null<std::unique_ptr<int>> a{std::make_unique<int>(0)};
+        gsl::strict_not_null<std::unique_ptr<int>> b{std::make_unique<int>(1)};
+
+        EXPECT_TRUE(*a == 0);
+        EXPECT_TRUE(*b == 1);
+
+        gsl::swap(a, b);
+
+        EXPECT_TRUE(*a == 1);
+        EXPECT_TRUE(*b == 0);
+    }
+
+    static_assert(!SwapCompilesFor<NotMoveAssignableCustomPtr>,
+                  "!SwapCompilesFor<NotMoveAssignableCustomPtr>");
+}
+
+TEST(pointers_test, member_types)
+{
+    static_assert(std::is_same<gsl::not_null<int*>::element_type, int*>::value,
+                  "check member type: element_type");
+}
+
+TEST(pointers_test, hash_noexcept_compiles)
+{
+    {
+        using Key = gsl::not_null<std::shared_ptr<int>>;
+        static_assert(noexcept(std::hash<Key>{}(std::declval<Key>())),
+                      "gsl::not_null hash operator must be noexcept");
+    }
+
+    {
+        using Key = gsl::strict_not_null<std::shared_ptr<int>>;
+        static_assert(noexcept(std::hash<Key>{}(std::declval<Key>())),
+                      "gsl::strict_not_null hash operator must be noexcept");
+    }
+}
+
+} // namespace