File::Glob::bsd_glob() just calls the C library function doglob(), which is unlikely to be sensitive to the perl context.

File::Glob::csh_glob() maintains an iterator over the list of results and does some wantarray checking to deliver either the whole list or one path at a time. That is an occasional perl convention.

I expect bsd_glob() could be written that way, too. DWIM sometimes means doing what someone else means ;-)