You can use a deque as a stack (First In, Last Out) or as a queue (First In, First Out). Lists are especially inefficient when adding/removing from the beginning of the list, but, for deques, it’s a O(1) operation.

I’m with you. Also, it seems like it would be much more efficient to do carbon capture at the source, where the fuel is being used, like a power plant, where the concentrations are relatively high, compared to atmospheric capture where CO2 is less than 0.1%.

I wish Apple wouldn’t restrict them as much as they do.