"kthomases" writes:

for_each(my_map.begin(), my_map.end(), boost::bind(&Point::Reset, _1));

Does this bound function actually select the pair's "second" member to call the function on? It looks at though it will fail to compile, expecting the applied first argument to be convertible to the UDT Point. -- Steven E. Harris :: seharris@raytheon.com Raytheon :: http://www.raytheon.com

Douglas Gregor writes:

Boost.Bind can do that:

for_each(my_map.begin(), my_map.end(), bind(&Point::Reset, bind(&map::value_type::second, _1)));

So can Boost.Lambda:

for_each(my_map.begin(), my_map.end(), bind(&Point::Reset, (&_1)->*&map::value_type::second));

Again, I can't see how this can work. "second" is the name of a member, not a function. You need a "pair select functor" to grab the first or second member from a pair. I've written a couple of these to use in conjunction with the projection_iterator adaptor. template <class P> struct select_pair_first : public std::unary_function { inline result_type& operator()(argument_type& arg) const { return arg.first; } inline const result_type& operator()(const argument_type& arg) const { return arg.first; } }; template <class P> struct select_pair_second : public std::unary_function { inline result_type& operator()(argument_type& arg) const { return arg.second; } inline const result_type& operator()(const argument_type& arg) const { return arg.second; } }; -- Steven E. Harris :: seharris@raytheon.com Raytheon :: http://www.raytheon.com

Douglas Gregor writes:

It works, I promise :)

Boost.Bind has an overload that supports pointers to data members by automagically transforming them into unary function objects.

Wow. What does the syntax look like for deducing when an argument is of type pointer to member variable? -- Steven E. Harris :: seharris@raytheon.com Raytheon :: http://www.raytheon.com