Re: [boost] [cpo-proposal] presentation of the idea

Subject: Re: [boost] [cpo-proposal] presentation of the idea
From: Thorsten Ottosen (thorsten.ottosen_at_[hidden])
Date: 2013-08-19 10:41:22

On 19-08-2013 16:30, Larry Evans wrote:
> On 08/19/13 09:06, Thorsten Ottosen wrote:

>> Since the size of vector<T*> is no bigger than vector<size_t>, it's
>> probably better just to allow forward iteration and then let the user
>> create a vector<T*> as they want (for full random access manipulation).
>>
>> -Thorsten
>>
> However I assume you meant vector<T*> to contain pointers to elements
> in the vector<char> storage of the container.  But what happens if
> storage needs to be resized?  OTOH, using vector<std::size_t> to
> store the offsets would not be invalidated by resizing storage.

True, there are different tradeoffs.

At least in my use cases, the objects would be loaded at application
start, and remain in memory until the application exists. Therefore,
I can create a vector<T*> object after loading the data and rely on the 
pointers to be valid throughout the entire application lifetime.

Perhaps push_back should return the offset instead, leaving it up to the
user if he needs to store the offset or the pointers?

Anyway, I think the basic functionality of this library should
strive for minimal overhead, and then perhaps expose various
container adaptors that add more functionality.

regards

-Thorsten