class="computeroutput">f()</code>. Assertions within this functor are usually programmed using  <code class="computeroutput"><a class="link" href="BOOST_CONTRACT_ASSERT.html" title="Macro BOOST_CONTRACT_ASSERT">BOOST_CONTRACT_ASSERT</a></code>, but any exception thrown by a call to this functor indicates a contract assertion failure (and will result in this library calling  <code class="computeroutput"><a class="link" href="boost/contract/except_failure.html" title="Function except_failure">boost::contract: