Implementation of a multimap data structure, i.e. an unordered
collection of key-value pairs:
$$f: keys -> values.$$
Multimaps are able to store several identical keys. For a data structure
which unique keys, see hashmap.
Inserting and accessing is amortized in O(1).
hashmap wraps a C++ unordered_multimap using Rcpp modules.
Also see bimap for mappings in both ways.
.mapC++ object representing a mapping
.key.classthe class of the keys
multimap for creating a new multimap object