s/class \s+ (?<class_name> \w+) \s* 
(\: (\s* \w*)? \s* (?<ancestor> \w+))? \s* 
$braces
//x

##</code><code>##

 
$braces = qr/(?<braces>\{ ([^\{\}] | (?&braces))*? \} )/x;

##</code><code>##

s/class \s+ (?<class_name> \w+) \s* 
(\: (\s* \w*)? \s* (?<ancestor> \w+))? \s* 
\{ (?<class_body>  [\s\S]+ ) \} \s*;
//xm