rit.Qi</em></span> requires the use of the following
        types of iterator: forward, bidirectional, or random access. Because of backtracking,
        input iterators cannot be used. Therefore, the standard library classes
        <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">istreambuf_iterator</span></code> and <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier"