22 Containers library [containers]

22.7 Views [views]

22.7.3 Class template span [views.span]

22.7.3.4 Observers [span.obs]

constexpr index_type size() const noexcept;
Effects: Equivalent to: return size_­;
constexpr index_type size_bytes() const noexcept;
Effects: Equivalent to: return size() * sizeof(element_­type);
[[nodiscard]] constexpr bool empty() const noexcept;
Effects: Equivalent to: return size() == 0;