my $wrap = 76;
my $tab  = 4;   # spaces occupied by tab
while(<DATA>) {
    do{ print; next } if length($_) < $wrap;
    do{ print "\n"; next } if m/^\s*$/;
    s/^(\s*)(?=\S)// or die "Choked on $_\n";
    my $indent = $1;
    my $l_wrap = $wrap - length($indent) - $tab;
    my @bits = $_ =~ m/\G(.{1,$l_wrap})\s+/gc;
    for ( my $i = 0; $i <@bits; $i++ ) {
        print $i == 0 ? "$indent$bits[$i]\n" : "$indent\t$bits[$i]\n";
    }
}


__DATA__
class ClassMyClassNameNoMatterHowLongItIsName:public BaseClass
{
    blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah
public:
    blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah blah
}

__END__
class ClassMyClassNameNoMatterHowLongItIsName:public BaseClass
{
    blah blah blah blah blah blah blah blah blah blah blah blah blah
    	blah blah blah blah blah blah blah blah blah blah blah blah blah
    	blah blah blah blah blah blah blah blah blah blah blah blah blah
    	blah blah blah
public:
    blah blah blah blah blah blah blah blah blah blah blah blah blah
    	blah blah blah blah blah blah blah blah
}