Re: [boost] [container] moving a pre-built vector into a flat_set

Subject: Re: [boost] [container] moving a pre-built vector into a flat_set
From: Thorsten Ottosen (tottosen_at_[hidden])
Date: 2015-09-16 09:23:54

On 16-09-2015 14:13, Sam Kellett wrote:
>>
>>> [snip]
>>
>>
>>
>> how come? i get that it's exposing the implementation, but the gains would
>>> be so so massive. and the name flat_ basically confirms the use of a
>> sorted
>>> vector internally.
>>
>> Moving in a std::vector would force the flat_set to be implemented in
>> terms of a
>> std::vector. However, what about a type from flat_set, e.g.
>> flat_set<T>::storage
>> and document what concept this storage implements (e.g. Random Access
>> Container), and then we could do what you want in a maybe cleaner way.
>>
>> flat_set<T>::storage data;
>> // fill data
>> flat_set<T> the_set{std::move(data)};
>>

Well, almost.

IMO, we need three things to make it perfect:

A. flat_set/map should have an additional template argument specifying 
the internal vector type (it can default to the current choice).

B. You should be able to move the whole container, as suggested.

C. The constructor should contain an assertion with a call to is_sorted()

kind regards

-Thorsten