><span class="identifier">std</span><span class="special">::</span><span class="identifier">cerr</span></code> and
      terminates the program calling <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">terminate</span></code>
      (this behaviour can be customized to take any user-specified action including
      throwing exceptions, see <a class="link" href="boost_contract/advanced.html#boost_contract.advanced.throw_on_failures__and__no