Regex without 'm' or '/'

Select or download this
if($query=~$term) {...}

     if ( 'abc' =~ 'bc' ) {
        print "yes\n";
     }

Select or download this

     if ( 'abc' =~ m/bc/ ) {  # good
     if ( 'abc' =~  /bc/ ) {  # good
     if ( 'abc' =~ m%bc% ) {  # good (for any non-alphanum)
  but:
     if ( 'abc' =~  'bc' ) {  # BAD! (or so we assume)

Select or download this

     if ( 'abc' =~ 'bc' ) {       # works
     if ( 'abc' =~ $pattern ) {   # works
     if ( 'abc' =~ "$pattern" ) { # works
     if ( 'abc' =~ bc ) {         # works!!
     if ( 'abc' =~ 'bc'g ) {      # Error: bareword 'g'

Select Code to Download