'keyword'>bool</SPAN> test_input_filter( InputFilter filter, 
                        <SPAN CLASS='keyword'>const</SPAN> std::string&amp; input,
                        <SPAN CLASS='keyword'>const</SPAN> std::string&amp; output );

<SPAN CLASS='keyword'>template</SPAN>&lt;<SPAN CLASS='keyword'>typename</SPAN> InputFilter, <SPAN CLASS='keyword'>typename</SPAN> Source1, <SPAN CLASS='keyword'>typename</SPAN> Source2&gt;
<SPAN CLASS='keyword'>bool</SPAN> test_input_filter( InputFilter filter, 
                 