Neal D. Becker wrote:
I ran into the following problem. I have an algorithm which looks like:
template<typename in_t, typename out_t> void Alg (in_t in, in_t inend, out_t out) { for (; in != inend; in++, out++) do_something() }
Now if I want to call this algorithm more than once, it would be convenient to pass out by ref, so it would be incremented:
Alg (v.begin(), v.end(), boost::ref (out)) that is, pass a reference to some kind of output iterator
this fails, because boost::ref doesn't have operator++ defined for reference_wrapper.
My question is, should boost::ref forward operators like ++ so that this would work?
To make it work you can use the 'unwrap' function template just like it is in "boost/bind.hpp" and "boost/mpl/aux_/unwrap.hpp". You algorithm would look like this: template<typename in_t, typename out_t> void Alg (in_t in, in_t inend, out_t out) { for (; in != inend; in++, unwrap(out)++) do_something() } -- Maxim Yegorushkin MetaCommunications Engineering http://www.meta-comm.com/engineering/