C:/Perl_524/bin\perl.exe -w d:/exp/pm_signatures.pl 
ok 1 - <foo(qw//)> 	 ERR: Too few arguments: 
ok 2 - <foo(qw/a/)> 	 One arg: @_ == 1
ok 3 - <foo(qw/a b/)> 	 Two args: @_ == 2
ok 4 - <foo(qw/a b c/)> 	 ERR: Too many arguments: 
1..4