[libcxx-commits] [libcxx] [libc++] Introduce `__product_iterator_traits` and optimise `flat_map::insert` (PR #139454)

[Louis Dionne via libcxx-commits]

================
@@ -0,0 +1,69 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___PRODUCT_ITERATOR_H
+#define _LIBCPP___PRODUCT_ITERATOR_H
----------------
ldionne wrote:

```suggestion
#ifndef _LIBCPP___ITERATOR_PRODUCT_ITERATOR_H
#define _LIBCPP___ITERATOR_PRODUCT_ITERATOR_H
```

https://github.com/llvm/llvm-project/pull/139454