introspection_library.tti_nested_type.the_problem"></a></span><a class="link" href="tti_nested_type.html#the_type_traits_introspection_library.tti_nested_type.the_problem">The
      problem</a>
    </h4>
<p>
      The metafunctions generated by the TTI macros all work with various types,
      whether in specifying an enclosing type or in specifying the type of some inner
      element, which may also involve types in the signature of that element, such
      as a parameter or return type of a function. The