"#BOOST_IDENTITY_TYPE" title="Macro BOOST_IDENTITY_TYPE">BOOST_IDENTITY_TYPE</a></code>
      macro is used to wrap a function template parameter, the template parameter
      can no longer be automatically deduced by the compiler form the function call
      as <code class="computeroutput"><span class="identifier">f</span><span class="special">(</span><span class="identifier">a</span><span class="special">)</span></code> would
      have done. <sup>[<a name="boost_utility_identitytype.templates.f0" href="#