c:\@Work\Perl>perl -wMstrict -le
"my $line = qq{xyz\x80\x90\xa0abc};
 print qq{'$line'};
 ;;
 $line !~ s/[^[:ascii:]]//g;
 print qq{'$line'};
"
Useless use of negative pattern binding (!~) in void context at -e line 1.
'xyzÇÉáabc'
'xyzabc'