Important note: this article is outdated! Go to http://zsiciarz.github.io/24daysofrust/ for a recent version of all of 24 days of Rust articles. The blogpost here is kept as it is for historical reasons.
AnyMap type is different from a regular map. For example, a
HashMap in Rust is a generic type parametrized by
K - the type of keys and
V - the type of values stored in map. (There's also a hasher parameter, but it's not relevant here.) Meanwhile,
AnyMap itself is not a generic type. It uses a
HashMap internally but we don't need to know that; conceptually,
AnyMap maps from types to values. This means that for each and every type there can be at most one value contained in the mapping.