const charT* c_str() const noexcept;
const charT* data() const noexcept;
Returns: A pointer p such that p + i == &operator[](i) for each i in [0,size()].
Complexity: constant time.
Requires: The program shall not alter any of the values stored in the character array.
allocator_type get_allocator() const noexcept;
Returns: A copy of the Allocator object used to construct the string or, if that allocator has been replaced, a copy of the most recent replacement.