Standard Template Library Programmer's Guide

Equal range	a.equal_range(k)	pair<iterator, iterator> if a is mutable, otherwise pair<const_iterator, const_iterator>.
Bucket count	a.bucket_count()	X::size_type
Resize	a.resize(n)	void

Expression semantics

Name	Expression	Precondition	Semantics	Postcondition
Default constructor	X() X a;		Creates an empty container, using hasher() as the hash function and key_equal() as the key equality function.	The size of the container is 0. The bucket count is an unspecified default value. The hash function is hasher(), and the key equality function is key_equal().
Constructor with bucket count	X(n) X a(n);		Creates an empty container with at least n buckets, using hasher() as the hash function and key_equal() as the key equality function.	The size of the container is 0. The bucket count is greater than or equal to n. The hash function is hasher(), and the key equality function is key_equal().
Constructor with hash function	X(n, h) X a(n, h);		Creates an empty container with at least n buckets, using h as the hash function and key_equal() as the key equality function.	The size of the container is 0. The bucket count is greater than or equal to n. The hash function is h, and the key equality function is key_equal().
Constructor with key equal	X(n, h, k) X a(n, h, k);		Creates an empty container with at least n buckets, using h as the hash function and k as the key equality function. The size of the container is 0.	The bucket count is greater than or equal to n. The hash function is h, and the key equality function is k.
Hash function	a.hash_funct()		Returns the hash function used by a.
Key equal	a.key_eq()		Returns the key equal function used by a.
Erase key	a.erase(k)		Destroys all elements whose key is the same as k, and removes them from a. [2]The return value is the number of elements that were erased, i.e. the old value of a.count(k).	a.size() is decremented by a.count(k) . a contains no elements with key k.
Erase element	a.erase(p)	p is a dereferenceable iterator in a.