This code:

let map = DashMap::<i32, i32>::new();
map.insert(1, 2);
let a = map.get_mut(&1);
let b = map.get(&1);

will deadlock. The shard containing 1 gets write-locked, nothing else can access it. This is reasonable behavior but I think it should be documented.

Perhaps more surprising is that this code:

let map = DashMap::<i32, i32>::new();

for i in 0..100

https://github.com/cplusplus/draft/releases/tag/n4849

The docs do not say whether opening the database also reads the database or whether I have to Database::load() it.