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Re: [std-proposals] Making contiguous objects

From: Breno Guimarães <brenorg_at_[hidden]>
Date: Sun, 12 Mar 2023 16:19:27 -0300
Oh ok. The library does provide multiple ways to construct the objects in
the array. So I don't think that's an issue.
See the test here:
I'm now in process of changing the implementation of libc++ shared_ptr to
stress the API. Let's see how it goes.

By the way, the configurability of the initialization of each array is
highly questionable because I haven't seen anything similar in the
standard. So I might need to a more traditional approach?
I don't know, what do you think?

Breno G.

On Sun, Mar 12, 2023 at 4:05 PM Arthur O'Dwyer <arthur.j.odwyer_at_[hidden]>

> On Sun, Mar 12, 2023 at 2:50 PM Breno Guimarães <brenorg_at_[hidden]> wrote:
>> > All our use-cases so far are use-cases for the
>> allocating-but-not-constructing entrypoint.
>> Even on std::make_shared<std::string[]>(10) ? That is a case of
>> allocating and constructing.
> That default-constructs the 10 string objects, true. But it *doesn't*
> default-construct the 1 _ControlBlock object that precedes them:
> https://github.com/llvm/llvm-project/blob/2f887c9a760dfdffa584ce84361912fe122ad79f/libcxx/include/__memory/shared_ptr.h#L1147-L1148
> So an entrypoint that default-constructs all Ns... of the Ts... isn't
> helpful to this use-case.
> –Arthur

Received on 2023-03-12 19:19:39