class range<T> meta¶

using value_type      = T

using reference       = T&

using const_reference = const T&

using pointer         = T*

using const_pointer   = const T*

using diff_type       = decltype(std::declval<T>() - std::declval<T>())

constexpr range(value_type begin, value_type end, diff_type step) noexcept
    : min(begin), max(end), step(step) { … }

struct iterator { … }

value_type min

value_type max

diff_type step

constexpr iterator begin() const { … }

constexpr iterator end() const { … }

constexpr T distance() const { … }