std::unordered_map<Key,T,Hash,KeyEqual,Allocator>::at

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Containers library
Sequence
(C++11)
Associative
Unordered associative
Adaptors
Views
(C++20)
 
 
T& at( const Key& key );
(1) (since C++11)
const T& at( const Key& key ) const;
(2) (since C++11)

Returns a reference to the mapped value of the element with key equivalent to key. If no such element exists, an exception of type std::out_of_range is thrown.

Parameters

key - the key of the element to find

Return value

Reference to the mapped value of the requested element

Exceptions

std::out_of_range if the container does not have an element with the specified key

Complexity

Average case: constant, worst case: linear in size.


See also

access or insert specified element
(public member function)