log10
=====

POSIX specification:
 https://pubs.opengroup.org/onlinepubs/9699919799/functions/log10.html

Gnulib module: log10 or log10-ieee

Portability problems fixed by either Gnulib module log10 or log10-ieee:

Portability problems fixed by Gnulib module log10-ieee:

  * This function returns a wrong value for a negative argument on some platforms: NetBSD 5.1, Solaris 11.4.

Portability problems not fixed by Gnulib: