nullability annotations in C

Posted Feb 12, 2025 8:41 UTC (Wed) by alx.manpages (subscriber, #145117)
In reply to: nullability annotations in C by interalia
Parent article: Maintainer opinions on Rust-for-Linux

> Out of interest, what are the compiler version requirements to use the new string functions?

Any compiler that supports C11 should be able to support these.

Here's an example of how to write such a const-generic API:

```
alx@devuan:~/tmp$ cat strchr.c
const char *my_const_strchr(const char *s, int c);
char *my_nonconst_strchr(char *s, int c);

#define my_strchr(s, c) \
( \
_Generic(s, \
char *: my_nonconst_strchr, \
void *: my_nonconst_strchr, \
const char *: my_const_strchr, \
const void *: my_const_strchr \
)(s, c) \
)
alx@devuan:~/tmp$ gcc -Wall -Wextra -pedantic -S -std=c11 strchr.c
alx@devuan:~/tmp$
```