On Monday, 3 July 2017 at 17:06:10 UTC, Ali Çehreli wrote:
On 07/02/2017 07:56 PM, Stefan Koch wrote:
On Monday, 3 July 2017 at 02:51:49 UTC, Filip Bystricky wrote:
Anyone?

The answer is no.

Partial deallocation in an arbitrary fashion is not advisable.

And there are no standard library mechanisms for it.

Would it be possible to write a custom std.experimental.allocator that does this?

Since the `deallocate` function an Allocator has to implement takes a `void[]` (-> known size), it's possible: At deallocation the Allocator will have to check if the given memory subblock lies within any of the previously allocated memory blocks; if it does, it will have to "tear" the to-be-deallocated memory subblock from within it, storing the resulting prefix and suffix memory subblocks (both remain allocated) and removing the original block. It will still have to track those two subblocks as belonging together, though, since it can only deallocate the original memory block back to the parent allocator (another Allocator, or something else) once both of these subblocks are no longer allocated. Obviously this applies to further partial deallocations of subblocks within subblocks. I tend to agree with Stefan that this is likely not sensible, but if in doubt, benchmark for the specific use case.

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