> By the way maps often use a large bucket, and rehash in-place can be preferable.
std::unordered_map (what I'm guessing you meant by a hashmap) uses a linked list for the nodes. There's no movement in the first place to worry about being realloc'd.
> Do you know a modern operating system that does not have a mremap equivalent ?
You have to be very large before most mallocs will put you on a dedicated mmap that can even be mremap'd at all.
If you're working with stonking huge data inline in a std:: vector... Yeah just make a container for that usage, not really an issue. There's tons of examples out there, typically to add SSO but doing realloc would be the same basic thing.
std::unordered_map (what I'm guessing you meant by a hashmap) uses a linked list for the nodes. There's no movement in the first place to worry about being realloc'd.
> Do you know a modern operating system that does not have a mremap equivalent ?
You have to be very large before most mallocs will put you on a dedicated mmap that can even be mremap'd at all.
If you're working with stonking huge data inline in a std:: vector... Yeah just make a container for that usage, not really an issue. There's tons of examples out there, typically to add SSO but doing realloc would be the same basic thing.