t proposal for
      adding contracts to C++ <a class="link" href="boost_contract/bibliography.html#P0380_anchor">[P0380]</a> will actually
      be accepted by the standard. <a href="#ftn.boost_contract.introduction.f3" class="footnote" name="boost_contract.introduction.f3"><sup class="footnote">[5]</sup></a> In any case, at least for now <a class="link" href="boost_contract/bibliography.html#P0380_anchor">[P0380]</a>
      only supports pre- and postconditions while missing basic features such as
      cl