how to know if bug 198092 applied in C program?

[andrew clarke]

On Tue 2016-02-23 07:07:30 UTC+0000, Koichiro IWAO (meta at vmeta.jp) wrote:

> Hello,
> 
> I'm writing a C program and having a question.
> 
> My program is intended to run under stable/9, releng/9.3, stable/10,
> releng/10.2, releng/10.3 and sometimes current.  Stables are not always
> up to date.
> 
> I'd like to check if getaddrinfo(3) supports AI_V4MAPPED using something
> like "#ifdef" or "#if" macros because it is not necessarily 
> implemented[1].
> Probably I can use __FreeBSD_version for that.  Is this way good?

I think you could use a configure script (not necessarily Autoconf)
instead, and test for AI_V4MAPPED support at build time.

https://en.wikipedia.org/wiki/Configure_script