On 5/28/26 06:55, Adrian Johnston via Std-Proposals wrote:

> *vector* - The vector is sized to its maximum size before use. It will

C++26 added std::inplace_vector.

> *hash_table/map/set* - Again, the hash table is sized to a maximum
> power-of-two before use. This has the effect of substantially reducing

C++23 added std::flat_set, std::flat_map, and their multi counterparts.

You may be interested in following the work of SG14

   https://lists.isocpp.org/mailman/listinfo.cgi/sg14
   https://github.com/WG21-SG14/SG14