tr!

/*
 *  call-seq:
 *     str.tr!(from_str, to_str)   => str or nil
 *  
 *  Translates <i>str</i> in place, using the same rules as
 *  <code>String#tr</code>. Returns <i>str</i>, or <code>nil</code> if no
 *  changes were made.
 */

static VALUE
rb_str_tr_bang(str, src, repl)
    VALUE str, src, repl;
{
    return tr_trans(str, src, repl, 0);
}