getting a range from a vector

[mikej]

Hi,
I apologize if this is too basic a quesiton.

I have a vector<Date> where Date is a class representing a Date. Dates are inserted into the vector in ascending order.

1. I want to get a vector of all the dates upto and including a given date. If the given date is not there, I want to dates upto the given date.

2. I want to provide a begin and end dates. I want to get all the dates in that range. Begin and end dates may not necessarity in the intial vector.

How do I do that. I was looking at find algorithm, but couldn't quite figure out how to do that.

Any help is really appreciated. Many thanks.

John

[Duthomhas]

You want the upper_bound and lower_bound algorithms.

To copy out a subvector, use a back_insert_iterator:

#include <algorithm>
#include <iterator>
...
#include <vector>
using namespace std;

class Date
  {
  ...
  bool operator < ( const Date& that )
    {
    // return true if (*this < that)
    }
  };

vector <Date> all_dates;
vector <Date> some_dates;

copy(
  lower_bound( all_dates.begin(), all_dates.end(), Date( '2007-2-10' ) ),
  upper_bound( all_dates.begin(), all_dates.end(), Date( '2008-4-28' ) ),
  back_inserter( some_dates )
  );

// now some_dates lists all dates from 2007-2-10 to 2008-4-28, inclusive 

Hope this helps.

[mikej]

thank you very much.

John

[Duthomhas]

Glad to have helped.

BTW, a lot of people are scared of the STL and would not have considered this a basic question.

It has limits _{and it sure is obnoxious and frustrating when you hit them} but often you just need to stare at it a bit and think sideways.

:-]

[mikej]

Thanks much for the encouragement. Knowing there are a very nice people like yourself out there who are ready to help is a big relief for beginners like myself.

Thanks again.

John