std::unordered_map::at

T& at( const Key& key );

const T& at( const Key& key ) const;

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

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