Re: [Boost-users] doubt on lambda expression

Subject: Re: [Boost-users] doubt on lambda expression
From: Roman Perepelitsa (roman.perepelitsa_at_[hidden])
Date: 2009-11-11 07:20:26

2009/11/11 Emanuele Rocci <rocciemanuele_at_[hidden]>

>  Hi All
> I started playing with boost::lambda and I need some help or some
> clarification about it
> or some hint to better understanding how does it work.
>
> I have this piece of code
>
> using namespace boost::lambda;
> using boost::lambda::var;
>
> int main(int argc, char** argv) {
>    std::vector< int > myList;
>    myList.push_back(100);
>    myList.push_back(200);
>    int interval = 20;
>
>    std::for_each( myList.begin(), myList.end(),
>         (
>         std::cout << "value: " << _1 << "\n",
>         std::cout << "interval: " << var( interval ) << "\n",
>         var( interval )++
>         ));
> }
>

Instead of
  std::cout << "value: " << _1 << "\n",
do this
  std::cout << constant("value: ") << _1 << "\n",

It's described here:
http://www.boost.org/doc/libs/1_40_0/doc/html/lambda/using_library.html#lambda.introductory_examples
.

By the way, if you are just starting with lambda, it's better to use
Boost.Phoenix instead.

Roman Perepelitsa.