On 9/19/06, Flex Ferrum <flex_ferrum@artberg.ru> wrote:
Hello, Alexander Shyrokov,
You wrote:
> I want to convert values according to a map before inserting it into the
> list. What is a proper way to do that?
> I have this:
> map<int,int> m;
> vector<int> a,b;
> for(vector<int>const_iterator i=a.begin();i!=a.end();++i)
> b.push_back(m[*i]);
> I could use std::copy with std::back_inserter to add elements to b, but
> how do I convert it first? Should I write my own version of
> back_inserter for that?
> copy(a.begin(),a.end(),my_back_inserter(b,m));
> Thanks.
Try this:
#include <boost/lambda/lambda.hpp>
using namespace boost;
using namespace boost::lambda;
//...
//...
map<int,int> m;
vector<int> a,b;
std::transform(a.begin(), a.end(), std::back_inserter(b), var(m)[_1]);
I would be really interested to know which of the various styles people find the best.
Tony