[libcxx-commits] [libcxx] [libc++][memory] Applied `[[nodiscard]]` to more functions (PR #172131)

[Hristo Hristov via libcxx-commits]

================
@@ -31,12 +38,28 @@ void test_allocator_traits() {
 }
 
 void test_allocator() {
-  std::allocator<int> allocator;
-  allocator.allocate(1);          // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
-#if TEST_STD_VER <= 17
-  allocator.allocate(1, nullptr); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
-#endif
+  [[maybe_unused]] std::allocator<int> allocator;
+
 #if TEST_STD_VER >= 23
   allocator.allocate_at_least(1); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
 #endif
+
+#if TEST_STD_VER <= 17
+  int i = 0;
+  const int ci = 0;
+
+  allocator.address(i);           // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+  allocator.address(ci);          // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+  allocator.allocate(1);          // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+  allocator.allocate(1, nullptr); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
----------------
H-G-Hristov wrote:

These are not available in C++20 and later and there is no opt out macro: 
https://github.com/llvm/llvm-project/blob/bcfa3216ce2f7db3b806b04fdc1bb65c834ba555/libcxx/include/__memory/allocator.h#L112

https://github.com/llvm/llvm-project/pull/172131