23 Strings library [strings]

23.3 String view classes [string.view]

23.3.3 Class template basic_string_view [string.view.template]

23.3.3.5 Capacity [string.view.capacity]

constexpr size_type size() const noexcept; constexpr size_type length() const noexcept;
Returns: size_.
constexpr size_type max_size() const noexcept;
Returns: The largest possible number of char-like objects that can be referred to by a basic_string_view.
[[nodiscard]] constexpr bool empty() const noexcept;
Returns: size_ == 0.