Partial arrays reclaimed?

[ag0aep6g via Digitalmars-d-learn]

On Friday, 27 January 2017 at 23:22:17 UTC, Nick Sabalausky wrote:
> Suppose an array is being used like a FIFO:
>
> -----------------------
> T[] slice;
>
> // Add:
> slice ~= T();
>
> // Remove:
> slice = slice[1..$];
> -----------------------
>
> Assuming of course there's no other references to the memory, 
> as this gets used, does the any of the memory from the removed 
> elements ever get GC'd?

If the array has no additional capacity, then appending will 
relocate the data. I.e., copy it to a larger allocation. The old 
data can then be collected. Since the old first element is not 
part of the new array, it's doesn't get copied over. So the 
allocation doesn't grow indefinitely.

> Also, if this is a long-running process, isn't there a 
> potential danger in the array just marching through the address 
> space and running out of room? (ie either running out of of 
> continuous space, or hitting 0xFFF....)

If you append and pop the front over and over, the program should 
reuse old locations, cycling through them.