Eric Niebler wrote:
Peter Dimov wrote:
Eric Niebler wrote:
Although I don't know all the details of bind and lambda, I had hoped that _1 and _2 would be abstract proto entities, such that
_1 == _2
creates an expression template like:
equal< terminal< arg<1> >, terminal< arg<2> > >
which is a generic, abstract representation of an equals expression with two placeholders. Can't bind and lambda both be implemented to recognize such a type and do the appropriate thing with it?
Possibly, if they are made to honor is_bind_expression specializations and result_of, if is_bind_expression reports true for the above type, if the above is a function object that actually returns x == y, and if result_of works for it.
Yes, that can all be made to work without much difficulty.
The part about boost::bind using is_bind_expression and result_of cannot, not without major surgery and possibly compromising portability. Sometimes I get excited about the new C++0x features and tell myself, why not rewrite boost::bind to take advantage of them? Then it occurs to me that C++0x has a std::bind built-in. :-) (Happened twice so far.)