FTL: Allow implicit conversions with NonNull<T>
C++ allows certain implicit conversions for pointers, such as the
implicit conversion of "T*" to "const T*".
NonNull did not allow them, but that is easily corrected.
Bug: 185536303
Flag: EXEMPT Relaxes a compile-time constraint
Test: atest ftl_test
Change-Id: I0c14805c8fdcca979c67d2c86d57e5e678aa1b32
diff --git a/libs/ftl/non_null_test.cpp b/libs/ftl/non_null_test.cpp
index 367b398..457237c 100644
--- a/libs/ftl/non_null_test.cpp
+++ b/libs/ftl/non_null_test.cpp
@@ -81,6 +81,31 @@
static_assert(std::is_same_v<decltype(ftl::as_non_null(std::declval<const int* const>())),
ftl::NonNull<const int*>>);
+class Base {};
+class Derived : public Base {};
+
+static_assert(std::is_constructible_v<ftl::NonNull<void*>, ftl::NonNull<int*>>);
+static_assert(!std::is_constructible_v<ftl::NonNull<int*>, ftl::NonNull<void*>>);
+static_assert(std::is_constructible_v<ftl::NonNull<const int*>, ftl::NonNull<int*>>);
+static_assert(!std::is_constructible_v<ftl::NonNull<int*>, ftl::NonNull<const int*>>);
+static_assert(std::is_constructible_v<ftl::NonNull<Base*>, ftl::NonNull<Derived*>>);
+static_assert(!std::is_constructible_v<ftl::NonNull<Derived*>, ftl::NonNull<Base*>>);
+static_assert(std::is_constructible_v<ftl::NonNull<std::unique_ptr<const int>>,
+ ftl::NonNull<std::unique_ptr<int>>>);
+static_assert(std::is_constructible_v<ftl::NonNull<std::unique_ptr<Base>>,
+ ftl::NonNull<std::unique_ptr<Derived>>>);
+
+static_assert(std::is_assignable_v<ftl::NonNull<void*>, ftl::NonNull<int*>>);
+static_assert(!std::is_assignable_v<ftl::NonNull<int*>, ftl::NonNull<void*>>);
+static_assert(std::is_assignable_v<ftl::NonNull<const int*>, ftl::NonNull<int*>>);
+static_assert(!std::is_assignable_v<ftl::NonNull<int*>, ftl::NonNull<const int*>>);
+static_assert(std::is_assignable_v<ftl::NonNull<Base*>, ftl::NonNull<Derived*>>);
+static_assert(!std::is_assignable_v<ftl::NonNull<Derived*>, ftl::NonNull<Base*>>);
+static_assert(std::is_assignable_v<ftl::NonNull<std::unique_ptr<const int>>,
+ ftl::NonNull<std::unique_ptr<int>>>);
+static_assert(std::is_assignable_v<ftl::NonNull<std::unique_ptr<Base>>,
+ ftl::NonNull<std::unique_ptr<Derived>>>);
+
} // namespace
TEST(NonNull, SwapRawPtr) {
@@ -156,4 +181,14 @@
EXPECT_TRUE(ftl::contains(spi, *spi.begin()));
}
+TEST(NonNull, ImplicitConversion) {
+ int i = 123;
+ int j = 345;
+ auto ip = ftl::as_non_null(&i);
+ ftl::NonNull<void*> vp{ip};
+ EXPECT_EQ(vp.get(), &i);
+ vp = ftl::as_non_null(&j);
+ EXPECT_EQ(vp.get(), &j);
+}
+
} // namespace android::test