8.220 expm1

POSIX specification:
http://www.opengroup.org/onlinepubs/9699919799/functions/expm1.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

• This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 9.