using const_iterator = implementation-defined;
For a
basic_string_view str, any operation that invalidates a pointer in the range
[str.data(), str.data() + str.size()) invalidates pointers, iterators, and references returned from
str's methods
.constexpr const_iterator begin() const noexcept;
constexpr const_iterator cbegin() const noexcept;
Returns:
An iterator such that
constexpr const_iterator end() const noexcept;
constexpr const_iterator cend() const noexcept;
Returns:
begin() + size(). constexpr const_reverse_iterator rbegin() const noexcept;
constexpr const_reverse_iterator crbegin() const noexcept;
Returns:
const_reverse_iterator(end()). constexpr const_reverse_iterator rend() const noexcept;
constexpr const_reverse_iterator crend() const noexcept;
Returns:
const_reverse_iterator(begin()).