@subheading stringprep_check_version
@anchor{stringprep_check_version}
@deftypefun {const char *} {stringprep_check_version} (const char * @var{req_version})
@var{req_version}: Required version number, or NULL.

Check that the version of the library is at minimum the requested one
and return the version string; return NULL if the condition is not
satisfied.  If a NULL is passed to this function, no check is done,
but the version string is simply returned.

See @code{STRINGPREP_VERSION}  for a suitable  @code{req_version} string.

Return value: Version string of run-time library, or NULL if the
run-time library does not meet the required version number.
@end deftypefun

