"Doug Gregor" <dgregor@cs.indiana.edu> wrote
On Jul 3, 2004, at 6:47 PM, Andy Little wrote:
I have seen this, but BTW I cant find the utilities/detail/result_of_iterate.hpp header in the boost CVS
??? It's there (and the regression tests are finding it). Are you using "cvs update -d"?
nope... IE explorer ie "the web browser cvs interface". All I'm seeing is an empty directory. I better rtm.
If we had "smarter" versions of std::plus, std::minus, etc. that played well with result_of, I think that would solve the issue reasonably well.
Are there moves in this direction?
... which is just a function object. Something like this:
struct minus ;
abracadabra...??? (*magic*).... struct minus { template<typename> struct result; template<typename F, typename T, typename U> struct result<F(T, U)> {//*** assuming this is not "automagic"??? ie require user specialization... typedef typename binary_operation<T,std::minus,U>::result_type type; };//*** template<typename T, typename U> typename result<minus(T, U)>::type operator()(T t, U u) { return t-u; } } ^^^ magic1 operator +(MyUDT<Ta> a, MyUDT<Tb> b); magic 2 operator -(MyUDT<Ta> a, MyUDT<Tb> b); etc operator * (MyUDT<Ta> a, MyUDT<Tb> b); etc operator / (MyUDT<Ta> a, MyUDT<Tb> b); template<typename Ta,template < typename> class Op, typename Tb> struct binary_operation< MyUDT<Ta>, Op, MyUDT<Tb> > { typedef MyUDT<typename binary_operation<Ta,Op,Tb>::result_type > result_type; }; How does the alternative to the above look? regards Andy Little