fix

Author: SchrodingerZhu

libc/src/__support/CPP/type_traits/has_unique_object_representations.h

@@ -9,14 +9,16 @@
 #define LLVM_LIBC_SRC___SUPPORT_CPP_TYPE_TRAITS_HAS_UNIQUE_OBJECT_REPRESENTATIONS_H
 
 #include "src/__support/CPP/type_traits/integral_constant.h"
+#include "src/__support/CPP/type_traits/remove_all_extents.h"
 #include "src/__support/macros/config.h"
 
 namespace LIBC_NAMESPACE_DECL {
 namespace cpp {
 
 template <class T>
 struct has_unique_object_representations
-    : public integral_constant<bool, __has_unique_object_representations(T)> {};
+    : public integral_constant<bool, __has_unique_object_representations(
+                                         remove_all_extents_t<T>)> {};
 
 template <class T>
 LIBC_INLINE_VAR constexpr bool has_unique_object_representations_v =

libc/test/src/__support/CPP/type_traits_test.cpp

@@ -439,6 +439,28 @@ TEST(LlvmLibcTypeTraitsTest, is_object) {
 
 TEST(LlvmLibcTypeTraitsTest, true_type) { EXPECT_TRUE((true_type::value)); }
 
+struct CompilerLeadingPadded {
+  char b;
+  int a;
+};
+
+struct CompilerTrailingPadded {
+  int a;
+  char b;
+};
+
+struct alignas(long long) ManuallyPadded {
+  int b;
+  char padding[sizeof(long long) - sizeof(int)];
+};
+
+TEST(LlvmLibcTypeTraitsTest, has_unique_object_representations) {
+  EXPECT_TRUE(has_unique_object_representations<int>::value);
+  EXPECT_FALSE(has_unique_object_representations_v<CompilerLeadingPadded>);
+  EXPECT_FALSE(has_unique_object_representations_v<CompilerTrailingPadded>);
+  EXPECT_TRUE(has_unique_object_representations_v<ManuallyPadded>);
+}
+
 // TODO type_identity
 
 // TODO void_t