https://svn.boost.org/trac10/ticket/6962 <p> boost::function::assign() member function is undocument. This function can assign allocator object one of the few way. I hope documentation this function. </p> <pre class="wiki">#include &lt;cassert&gt; #include &lt;memory&gt; #include &lt;boost/function.hpp&gt; struct increment { int operator()(int x) const { return x + 1; } }; int main() { boost::function&lt;int(int)&gt; f; f.assign(increment(), std::allocator&lt;increment&gt;()); assert(f(1) == 2); } </pre> en-us /htdocs/site/boost.png https://svn.boost.org/trac10/ticket/6962 Trac 1.4.3