brary.tti_nested_type.the_solution">The
      solution</a>
    </h4>
<p>
      The solution given by BOOST_TTI_MEMBER_TYPE is that we can create a type as
      the return from our metafunction, which is the same type as a nested type if
      it exists or some other marker type if it does not, and then work with that
      returned type without producing a compiler error. If we had to use the 'T::InnerType'
      syntax to specify our type, where 'T' represents out enclosing type and 'InnerType'
      our 