d Boost.Signals2, and
      indeed the original Boost.Signals was strongly influenced by
      Karl Nelson and libsigc++. A cursory inspection of each library will find a
      similar syntax for the construction of signals and in the use of
      connections. There
      are some major differences in design that separate these
      libraries:</p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem"><p><span class="bold"><strong>Slot definitions</strong><