[PING] cpp: new built-in __EXP_COUNTER__

[Kaz Kylheku via Gcc-patches]

On 2022-04-21 09:11, Kaz Kylheku wrote:
> libcpp/ChangeLog
> 2022-04-21  Kaz Kylheku  <k...@kylheku.com>
> 
>       This change introduces a pair of related macros
>       __EXP_COUNTER__ and __UEXP_COUNTER__.  These macros access
>       integer values which enumerate macro expansions.
>       They can be used for the purposes of obtaining, unique
>       identifiers (within the scope of a translation unit), as a
>       replacement for unreliable hacks based on __LINE__.