if</SPAN> (c != <SPAN CLASS="literal">'\n'</SPAN>)
            ++col_no_;
        <SPAN CLASS="keyword">else</SPAN>
            col_no_ = <SPAN CLASS='numeric_literal'>0</SPAN>;
    }</PRE>


<P>This function writes the given character to <CODE>std::cout</CODE> and increments the column number, unless the character is a newline, in which case the column number is reset. Using <CODE>put_char</CODE>, you can implement the <CODE>virtual</CODE> function <CODE>do_filter</CODE> as follows:</P>

<PRE class="broken