std::map<Key,T,Compare,Allocator>::at

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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

Logarithmic in the size of the container.

See also

access or insert specified element
(public member function)