How to use a sequence of statements in Boost.Phoenix together with std::transform?

Question

I'd like to use Boost.Phoenix to create a lambda function that consists of a few lines of code and then "returns" a value so I can use it together with std::transform.

Like this:

std::transform(a.begin(), a.end(), b.begin(),
        (
            //Do something complicated here with the elements of a:
            statement1,
            statement2,
            statement3
            //Is there a way to return a value here?
        )
        );

With std::for_each this would work perfectly, but with std::transform it does not compile because the comma operator returns void. How can I return a value from a lambda function like this?

---

Edit: I changed the code fragment because what I wrote in the first place led to misunderstandings about what I want to do.

Answer 1

No, this isn't possible. From the Boost.Phoenix v2 statement docs:

Unlike lazy functions and lazy operators, lazy statements always return void.

(Note that this same assertion is in the Boost.Phoenix v3 docs as well.)