Re: [boost] make_shared_array

Subject: Re: [boost] make_shared_array
From: Nathan Crookston (nathan.crookston_at_[hidden])
Date: 2012-11-01 20:32:39

Hi Glen,

On Thu, Nov 1, 2012 at 5:45 PM, Glen Fernandes <glen.fernandes_at_[hidden]> wrote:
> I have desired shared_ptr<T[]> for a while now; if it is considered
> appropriate for shared_ptr to support that I would like to help make
> that happen. My functions could be provided as just
> allocate_shared<T[]> and make_shared<T[]> in that case.
I'd definitely like that syntax best.  I'd be happy to work on such a
thing as well -- I'd just want to know if it's unacceptable from the
start.

> I agree that while named "make_shared_array" and
> "allocate_shared_array" they should really return shared_array<T>. I
> also like the suggestions Peter had to fix shared_array (e.g. nothrow
> construction) and perhaps to allow obtaining a shared_ptr<T> from
> shared_array<T>.
Due to my concerns with misusing a shared_ptr to polymorphic types,
I'd want such a conversion to be as visible as possible.  Given the
following:
shared_array<int> sa(new int[500]);
shared_ptr<int> sp1(sa);//1
shared_ptr<int[]> sp2(sa);//Hypothetical 2
shared_ptr<int> sp3 = static_pointer_cast<int>(sa);//3

I'd suggest 1 wasn't explicit enough (despite being explicitly
constructed), 2 would be just fine, and 3 (though overloading the
function might be unwise) would be fine for those that really want it.

Thanks,
Nate