# Lookup¶

The following table provides additional information on the members of the template classes concurrent_unordered_map and concurrent_unordered_multimap .

Member, Description

iterator find(const key_type& k)

Returns: iterator pointing to item with key equivalent to k, or end() if no such item exists.

const_iterator find(const key_type& k) const

Returns: const_iterator pointing to item with key equivalent to k, or end() if no such item exists.

size_type count(const key_type& k) const

Returns: Number of items with keys equivalent to k.

std::pair<iterator, iterator> equal_range(const key_type& k)

Returns: Range containing all keys in the map that are equivalent to k.

std::pair<const_iterator, const_iterator> equal_range(const key_type& k) const

Returns

Range containing all keys in the map that are equivalent to k.

The following table provides additional information on the members only available in the concurrent_unordered_map template class.

Member, Description

mapped_type& operator[](const key_type& k)

Inserts a new item if item with key equivalent to k is not already present.

Returns: Reference to x.second , where x is item in map with key equivalent to

k.

mapped_type& at( const key_type& k )

Throws exception if item with key equivalent to k is not already present.

Returns: Reference to x.second, where x is the item in map with key equivalent to k.

const mapped_type& at(const key_type& k) const

Throws exception if item with key equivalent to k is not already present.

Returns: Const reference to x.second, where x is the item in map with key equivalent to k.