Re: [Boost-Users] vector ranges

From: Kresimir Fresl (fresl_at_[hidden])
Date: 2003-06-10 01:20:49

cerenoc wrote:

> I just wanted to clarify if the following behavior is correct.  As 
> far as I understood, in matrix and vector range function, the 1st 
> argument defines the starting point and the second defines the 
> length of the range. 

No. First argument defines the starting point, but the second
defines `one past the end', similar to iterator ranges: [begin, end).
For example:

   range (0, 1)  =>  0
   range (0, 3)  =>  0 1 2
   range (1, 3)  =>  1 2
   range (2, 3)  =>  2
   range (3, 3)  =>  empty
   range (4, 3)  =>  assertation error

[On the other hand, when defining a slice, length is given by the
third argument (first is starting point, second is step (or stride)); e.g.:

   slice (0, 1, 3)   =>  0 1 2
   slice (1, 1, 3)   =>  1 2 3
   slice (1, 2, 3)   =>  1 3 5
]

Regards,

fres