std::experimental::shared_ptr<T>::operator (3) - Linux Manuals
element_type& operator(std::ptrdiff_t i) const noexcept; (library fundamentals TS)
Index into the array pointed to by the stored pointer.
The behavior is undefined if the stored pointer is null or if i is negative.
If T (the template parameter of shared_ptr) is an array type U[N], i shall be less than N, or the behavior is undefined.
i - the array index
A reference to the i-th element of the array , i.e., get()[i]
When T is not an array type, it is unspecified whether this function is declared. If the function is declared, it is unspecified what its return type is, except that the declaration (although not necessarily the definition) of the function is guaranteed to be legal.
This section is incomplete
Reason: no example
get (public member function)