[boost] boost::function overhead?

From: Neal Becker (ndbecker2_at_[hidden])
Date: 2006-05-02 08:53:51

I'd like to use boost::function to wrap (pointer to) function to pass to
template functions that expect function objects.  I'm just wondering,
though, if using boost::function wrapper will introduce additional overhead
into the function call?

example:

template<typename in_t, typename out_t, typename func_t>
inline void apply (in_t const& in, out_t out, func_t const&f) {
  typename boost::range_const_iterator<in_t>::type i = boost::begin (in);
  typename boost::range_iterator<out_t>::type o = boost::begin (out);
  for (; i != boost::end (in); ++i, ++o)
    *o = f (*i);
}

template<typename in_t, typename out_t>
inline void phaseDouble (in_t const& in, out_t &out) {
apply (in, out, lvalue_cast (boost::function<typename
boost::range_value<out_t>::type (typename boost::range_value<in_t>::type)>
(some function)));
  }
}