Subject: Re: [boost] [Intrusive]
From: Andrey Semashev (andrey.semashev_at_[hidden])
Date: 2017-08-23 22:49:52
On 08/24/17 01:18, Soul Studios via Boost wrote:
>> object is referenced by another API. The only alternative to
>> Boost.Intrusive is keeping a pointer to the object in a separate
>> container, which is way too cumbersome. Second is when you want your
>> object to be a member of multiple containers and you don't want or
>> cannot copy it.
>
> Storing a vector of pointers is not only less cumbersome than injecting
> structures into the original objects,
Having tried both, I will just have to disagree.
> it's less expensive.
> According to the Doom3 BFG technical note
> (fabiensanglard.net/doom3_documentation/DOOM-3-BFG-Technical-Note.pdf)
> a vector of indexes to a separate vector(s) of objects is significantly
> faster than an intrusive list. The same would be true for a vector of
> pointers (but less so).
> This approach is also amenable to multiple containers sharing objects.
Whether that is faster or not depends on many factors, primarilly the
use scenarios at hand. One can't make a general statement like that
without specifics. One factor that could make a vector more efficient
than a list is cache friendliness, but an intrusive list could exploit
it as well if you manage the storage appropriately.