Bibbity
Bobbity *foo::bar (baz) {

##</code><code>##

$ cat 1070117.pl 
#!/usr/bin/perl
use strict;
use warnings;

my $regex = qr/(.*?)\n((?:\w+\*?\s+)+)(\*?[:\w]+\s*)\s*\((.*?)\)(\s*\{)/;
my $text = "foo\nfizzy bar::baz(a b) {\nblarf\n";
if ($text =~ $regex) {
    print "Matched! $1, $2, $3\n";
}

$ perl 1070117.pl
Matched! foo, fizzy , bar::baz