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Re: On "transparently replaceable" in std::vector operations

From: Christopher Hallock <christopherhallock_at_[hidden]>
Date: Wed, 28 Apr 2021 10:38:07 -0400
On Wed, Apr 28, 2021 at 10:34 AM Christopher Hallock <
christopherhallock_at_[hidden]> wrote:

> On Tue, Apr 27, 2021 at 11:02 AM Giuseppe D'Angelo via Std-Discussion <
> std-discussion_at_[hidden]> wrote:
>> [vector.modifiers] says that inserting an element at position `p`
>> invalidates all iterators, references and pointers from position `p`
>> onwards.
>> I'm wondering why there's such a requirement for pointers (and
>> references) [...]
> This kind of Library provision, saying that iterators, pointers, and
> references to elements are invalidated upon condition X, seems overly broad
> even if you don't care about using pointers in an "index-like" way, because
> it means you can't safely use an element type that stores (and properly
> updates across moves/copies) the 'this' pointer as a member. I suspect that
> the real intent of this kind of provision is that it only applies to
> iterators, pointers, and references obtained through the container's API.

Gah, never mind. On further reflection, this is not actually a problem
because the member would be overwritten on copy/move.

Received on 2021-04-28 09:38:23