Re: [Boost-users] [boost-users][boost foreach, iterating]

From: Eric Niebler (eric_at_[hidden])
Date: 2007-12-02 15:01:08

chun ping wang wrote:
> hi, is their anyway where i can use boost foreach to iterate through two 
> different containers at once.
>  
> Like I have two vector of float and i want to iterate through them 
> parallell.. (not using indexing.. since it doesn't work with all types). 
> Thanks.
> 
> Something that is equalivent to python,
> for x,y in xArray, yArray:
>      # do some awesome stuff.
>      print x, y

Not directly, but you can get what you want with the help of some range 
adapters. I haven't tried it, but it looks like the "zipped" adapter 
from the Oven library can help here. See 
http://p-stade.sourceforge.net/oven/doc/html/oven/utilities.html#oven.utilities.zipped.

Untested:

typedef boost::tuple<float, float> point;
BOOST_FOREACH( point p, boost::make_tuple(xArray, yArray) | zipped )
{
    // do some awesome stuff
    std::cout << p.first << p.second;
}

Good luck!

-- 
Eric Niebler
Boost Consulting
www.boost-consulting.com