> The Lambda version would be similar, just replacing the outer bind with
> infix notation
>
> #include "boost/lambda/lambda.hpp"
> #include "boost/lambda/bind.hpp"
>
> using namespace boost::lambda;
>
> std::accumulate( begin, end, _1 + bind(&A::a, _2 ));
>
> Again untested.

this std::accumulate return complicated lambda function, but not int value :-)