Re: [container] Draft development plan for Boost.Container

From: Helmut Zeisel (HZ2012_at_[hidden])
Date: 2024-05-22 12:31:51

Gesendet:Â Mittwoch, 22. Mai 2024 um 08:45 Uhr
Von: "Ion Gaztañaga via Boost" <boost_at_[hidden]>

> A) "clear" in vectors does not reduce the capacity, I think that would
> be surprising because many times a user does not expect new allocations
> after clear() if the previous capacity was big enough.

OK

> B) Moving to internal storage when move assigning could make the
> operation throwing, when moving the dynamic buffer can be faster and
> nothrow. LLVM and Folly take the dynamic buffer of the source vector if
> available:

This is true when you move from a dynamic buffer.
If you move from the internal buffer, however, you must move the individual elements anyway.

> C) Swap is similar to a double move assignment.

The interesting situation is when one vector uses a dynamic buffer and the other one the internal buffer.
Currently swap allocates also a dynamic buffer for the vector with the internal buffer.

Helmut