/* * Access element * */ template <class Key, class T, class Cmp = less<Key>, class A = allocator< pair<const Key,T> > > class map { public: // ... mapped_type& operator[](const key_type& k); // access element with key k // ... }; /* * Usage of access element * */ void f() { map<string,int> m; // map starting out empty int x = m["Henry"]; // create new entry for "Henry", initialize to 0, return 0 m["Harry"] = 7; // create new entry for "Harry", initialize to 0, and assign 7 int y = m["Henry"]; // return the value from "Henry"'s entry m["Harry"] = 9; // change the value from "Harry"'s entry to 9 }