New comment by oreo639 on void-packages repository

https://github.com/void-linux/void-packages/issues/46959#issuecomment-1786455944

Comment:
> So, we move `basename` to `#ifdef __cplusplus`?

It would be `#ifndef`, which is already the case and also not this issue.
The issue here is that C23 removed support for the original pre-ANSI k&r style function declarations/definitions and `int func()` was made from meaning an old k&r style declaration to being equivalent to `int func(void)` just like how it has been in C++.

The idea in musl, is that they declare it using k&r style in `string.h` so that it would be available for glibc compatibility while not breaking applications that re-declare `basename()`, while having the proper definition in `libgen.h`.

The proper workaround here would smth like:
```
#if !defined(__cplusplus) || !(defined(__STDC_VERSION__) && __STDC_VERSION__ > 201710L)
char *basename();
#endif
```
Similar to what gcc does for `stdbool.h` (which was made irrelevant in C23).

Although this should probably be dealt with upstream before we patch it. (and the final C23 standard will not be published until earlier next year)