What is the definition of the unique function in C++?

In C++, the std::unique function is used to remove adjacent duplicate elements in a container, ensuring that each group of adjacent duplicate elements in the container only retains one. Its definition is as follows:

template< class ForwardIt >
ForwardIt unique( ForwardIt first, ForwardIt last );

template< class ForwardIt, class BinaryPredicate >
ForwardIt unique( ForwardIt first, ForwardIt last, BinaryPredicate p );

The first version of the function takes two iterator parameters, first and last, indicating the range of elements to be operated on in the container; the second version accepts an additional binary predicate p to customize the logic for determining equality. std::unique function returns an iterator pointing to the end position of the unique elements in the container.