Re: [boost] First lambda

6 Mar 2004


      David Abrahams wrote:
...
I just tried using the lambda library for the first time.  Here's
what came out of it, after some struggle:
#include <boost/lambda/lambda.hpp>
  #include <vector>
  #include <numeric>
using namespace boost::lambda;
struct X
  {
      X() : count(1) {}
unsigned long count;
  };
std::vector<X> xs(10);
  unsigned long n = std::accumulate(
      xs.begin(), xs.end(), 0UL,
      _1 + (&_2) ->* &X::count);
Views make it much cleaner, both conceptually and syntactically:

    unsigned long n = accumulate( 
          transform_view( xs, mem_fn(&X::count) )
        , 0UL
        );
        
--
Aleksey Gurtovoy
MetaCommunications Engineering