// Compile time check for packability. This requires that
// PackedSyncPtr is a POD struct on gcc.
-struct ignore { PackedSyncPtr<int> foo; char c; } __attribute__((packed));
+FOLLY_PACK_PUSH
+struct ignore { PackedSyncPtr<int> foo; char c; } FOLLY_PACK_ATTR;
+FOLLY_PACK_POP
static_assert(sizeof(ignore) == 9, "PackedSyncPtr wasn't packable");
}