Unordered sets are associative containers. They do not provide random access through an index. I.e. s[2]
does not return the second
element.
Unordered means that the container does not enforce elements to be stored in a particular order. This makes unordered sets in some applications faster
than sets. I.e., elements in unordered sets are unique, but not sorted.
C++ unordered_set methods implemented in this package are bucket_count, clear, contains, count, emplace,
empty, erase, insert, load_factor, max_bucket_count, max_load_factor, max_size, merge,
rehash, reserve, and size. The package also adds the == operator and various helper functions (print,
to_r, type).
All object-creating methods in this package begin with cpp_
to avoid clashes with functions from other packages, such as utils::stack
and
base::vector
.