On Sat, Aug 23, 2003 at 09:45:42AM -0400, Brian McNamara wrote:
> // use boost::lamdba
> boost::lexicographic<person>
> ( _1.first, cmp_lower ) /* see below */
> ( _1.last, cmp_lower )
> ( bind(&T::age,_1) /* use default cmp */ )
> ( p1, p2 )
...
> The problem (cited "see below") is that since operator "." isn't
> overloadable, the boost::lambda expressions like "_1.first" don't
> actually exist. Offhand I dunno if C++ in general or Boost in
> particular offers a nice way to lambda-ify such a member-variable
> expression.
I just looked at the boost::lambda documentation and see that they were
clever enough to make bind() work on member variables as well as member
functions. So the actual syntax would be
// Assume "p1.first", "p1.last", and "p1.age()" are all legal
boost::lexicographic<person>
( bind(&T::first,_1), cmp_lower )
( bind(&T::last,_1), cmp_lower )
( bind(&T::age,_1) /* use default cmp */ )
// above returns a comparator object; can add
( p1, p2 )
// to call it if desired
--
-Brian McNamara ([EMAIL PROTECTED])
_______________________________________________
Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
