Zitat von Cory Nelson :

On Fri, Aug 28, 2009 at 3:17 PM, Robert Dailey wrote:

...

Hello, I have a list of colors that I need to be able to cycle through, either by rotating the container or by using an iterator that will rotate (i.e. return to the beginning when I increment at the end, and vice-versa). The goal is to be able to iterate through the container in a circular way and process all of the colors repeatedly. I chose a boost::circular_buffer for this job, I assumed it was the perfect tool for the job. It works great, except I would like to be able to call push_back() to add all of my colors to the buffer without having to call set_capacity() on it first. It's a minor thing, but omitting the call to set_capacity() would make it slightly more scalable/manageable since I won't have to keep incrementing the size of the capacity each time I want to add colors to the buffer. How can I achieve this?

a circular buffer is designed to have a specific capacity. you can cycle through any container.

I'm not familiar with circular_buffer, but something quick n' dirty:

std::vector<color> colors;

colors.push_back(color()); ...

for(std::vector<color>::size_type i = 0; i < colors.size(); i = (i + 1) % colors.size()) { color &c = colors[i]; }

I've got an easier way to write that: while(true); if you want to end the iteration at some point: container::iterator it=start; while(...){ ... if(it == container.end()) it=container.begin(); } if you often need to do something like that consider writing an own iterator. that can be achieved in just a view lines of code in this case with boost::iterator_adaptor.