Is there a notion of const? Perhaps const iteration?

[kevindarby]

Thanks.

[mpoeter]

I suppose you mean the containers (harris_michael_list_based_set, harris_michael_hash_map, vyukov_hash_map). No, at the moment there is no const_iterator. There are also some functions that could theoretically be made const (like contains), but aren't at the moment. This is something I have on my todo-list, but unfortunately haven't found the time yet.