ranges::v3::view_facade< Derived, Cardinality > Struct Template Reference
Core

## Description

### template<typename Derived, cardinality Cardinality>
struct ranges::v3::view_facade< Derived, Cardinality >

A utility for constructing a view from a (derived) type that implements begin and end cursors.

Template Parameters

  Derived | A type that derives from `view_facade` and implements begin and end cursors. This type is permitted to be incomplete.
  Cardinality | The cardinality of this view: `finite`, `infinite`, or `unknown`. See `ranges::v3::cardinality`.

Inheritance diagram for ranges::v3::view_facade< Derived, Cardinality >:

## Public Member Functions

template<typename D = Derived, requires = (Same<D, Derived>())>
detail::facade_iterator_t< D > | begin ()
| Let `d` be `static_cast<Derived &>(*this)`. Let `b` be `std::as_const(d).begin_cursor()` if that expression is well-formed; otherwise, let `b` be `d.begin_cursor()`. Let `B` be the type of `b`. More...
template<typename D = Derived, requires = (Same<D, Derived>())>
detail::facade_iterator_t< D const > | begin () const
template<typename D = Derived, requires = (Same<D, Derived>())>
detail::facade_sentinel_t< D > | end ()
| Let `d` be `static_cast<Derived &>(*this)`. Let `e` be `std::as_const(d).end_cursor()` if that expression is well-formed; otherwise, let `e` be `d.end_cursor()`. Let `E` be the type of `e`. More...
template<typename D = Derived, requires = (Same<D, Derived>())>
detail::facade_sentinel_t< D const > | end () const
Public Member Functions inherited from ranges::v3::view_interface< Derived, Cardinality >
template<typename D = Derived, requires = (Same<D, Derived>() && RandomAccessRange<D>() && SizedRange<D>())>
auto | at (range_difference_type_t< D > n) -> decltype(std::declval< D &>().begin()[n])
| Returns a reference to the element at specified location pos, with bounds checking.
template<typename D = Derived, requires = (Same<D, Derived>() && RandomAccessRange<D const>() && SizedRange<D const>())>
auto | at (range_difference_type_t< D > n) const -> decltype(std::declval< D const &>().begin()[n])
template<typename D = Derived, requires = (Same<D, Derived>() && BoundedRange<D>() && BidirectionalRange<D>())>
range_reference_t< D > | back ()
| Access the last element in a range:
template<typename D = Derived, requires = (Same<D, Derived>() && BoundedRange<D const>() && BidirectionalRange<D const>())>
range_reference_t< D const > | back () const
constexpr bool | empty () const noexcept
template<typename D = Derived, requires = (Same<D, Derived>() && Cardinality < 0 && ForwardRange<D const>())>
constexpr bool | empty () const noexcept(noexcept(bool(ranges::begin(std::declval< D const &>())==ranges::end(std::declval< D const &>()))))
template<typename D = Derived, requires = (Same<D, Derived>() && ForwardRange<D>())>
range_reference_t< D > | front ()
| Access the first element in a range:
template<typename D = Derived, requires = (Same<D, Derived>() && ForwardRange<D const>())>
range_reference_t< D const > | front () const
template<typename D = Derived, requires = (Same<D, Derived>()), typename = decltype(ranges::empty(std::declval<D const &>()))>
constexpr | operator bool () const noexcept(noexcept(ranges::empty(std::declval< D const &>())))
template<typename Container , typename D = Derived, typename = typename Container::allocator_type, requires = (detail::ConvertibleToContainer<D, Container>())>
| operator Container ()
| Implicit conversion to something that looks like a container.
template<typename Container , typename D = Derived, typename = typename Container::allocator_type, requires = (detail::ConvertibleToContainer<D const, Container>())>
| operator Container () const
template<typename D = Derived, requires = (Same<D, Derived>())>
constexpr auto | operator! () const noexcept(noexcept(decltype(ranges::empty(std::declval< D const &>()))(ranges::empty(std::declval< D const &>())))) -> decltype(ranges::empty(std::declval< D const &>()))
view_interface & | operator= (view_interface &&)=default
view_interface & | operator= (view_interface const &)=default
template<typename D = Derived, requires = (Same<D, Derived>() && RandomAccessRange<D>())>
auto | operator[] (range_difference_type_t< D > n) -> decltype(std::declval< D &>().begin()[n])
| Simple indexing:
template<typename D = Derived, requires = (Same<D, Derived>() && RandomAccessRange<D const>())>
auto | operator[] (range_difference_type_t< D > n) const -> decltype(std::declval< D const &>().begin()[n])
template<typename D = Derived, typename Slice = view::slice_fn, requires = (Same<D, Derived>())>
auto | operator[] (detail::slice_bounds< range_difference_type_t< D >> offs) &-> decltype(std::declval< Slice >()(std::declval< D &>(), offs.from, offs.to))
| Python-ic slicing:
template<typename D = Derived, typename Slice = view::slice_fn, requires = (Same<D, Derived>())>
auto | operator[] (detail::slice_bounds< range_difference_type_t< D >> offs) const &-> decltype(std::declval< Slice >()(std::declval< D const &>(), offs.from, offs.to))
template<typename D = Derived, typename Slice = view::slice_fn, requires = (Same<D, Derived>())>
auto | operator[] (detail::slice_bounds< range_difference_type_t< D >> offs) &&-> decltype(std::declval< Slice >()(std::declval< D >(), offs.from, offs.to))
template<typename D = Derived, typename Slice = view::slice_fn, requires = (Same<D, Derived>())>
auto | operator[] (detail::slice_bounds< range_difference_type_t< D >, detail::from_end_< range_difference_type_t< D >>> offs) &-> decltype(std::declval< Slice >()(std::declval< D &>(), offs.from, offs.to))
template<typename D = Derived, typename Slice = view::slice_fn, requires = (Same<D, Derived>())>
auto | operator[] (detail::slice_bounds< range_difference_type_t< D >, detail::from_end_< range_difference_type_t< D >>> offs) const &-> decltype(std::declval< Slice >()(std::declval< D const &>(), offs.from, offs.to))
template<typename D = Derived, typename Slice = view::slice_fn, requires = (Same<D, Derived>())>
auto | operator[] (detail::slice_bounds< range_difference_type_t< D >, detail::from_end_< range_difference_type_t< D >>> offs) &&-> decltype(std::declval< Slice >()(std::declval< D >(), offs.from, offs.to))
template<typename D = Derived, typename Slice = view::slice_fn, requires = (Same<D, Derived>())>
auto | operator[] (detail::slice_bounds< detail::from_end_< range_difference_type_t< D >>, detail::from_end_< range_difference_type_t< D >>> offs) &-> decltype(std::declval< Slice >()(std::declval< D &>(), offs.from, offs.to))
template<typename D = Derived, typename Slice = view::slice_fn, requires = (Same<D, Derived>())>
auto | operator[] (detail::slice_bounds< detail::from_end_< range_difference_type_t< D >>, detail::from_end_< range_difference_type_t< D >>> offs) const &-> decltype(std::declval< Slice >()(std::declval< D const &>(), offs.from, offs.to))
template<typename D = Derived, typename Slice = view::slice_fn, requires = (Same<D, Derived>())>
auto | operator[] (detail::slice_bounds< detail::from_end_< range_difference_type_t< D >>, detail::from_end_< range_difference_type_t< D >>> offs) &&-> decltype(std::declval< Slice >()(std::declval< D >(), offs.from, offs.to))
template<typename D = Derived, typename Slice = view::slice_fn, requires = (Same<D, Derived>())>
auto | operator[] (detail::slice_bounds< range_difference_type_t< D >, end_fn > offs) &-> decltype(std::declval< Slice >()(std::declval< D &>(), offs.from, offs.to))
template<typename D = Derived, typename Slice = view::slice_fn, requires = (Same<D, Derived>())>
auto | operator[] (detail::slice_bounds< range_difference_type_t< D >, end_fn > offs) const &-> decltype(std::declval< Slice >()(std::declval< D const &>(), offs.from, offs.to))
template<typename D = Derived, typename Slice = view::slice_fn, requires = (Same<D, Derived>())>
auto | operator[] (detail::slice_bounds< range_difference_type_t< D >, end_fn > offs) &&-> decltype(std::declval< Slice >()(std::declval< D >(), offs.from, offs.to))
template<typename D = Derived, typename Slice = view::slice_fn, requires = (Same<D, Derived>())>
auto | operator[] (detail::slice_bounds< detail::from_end_< range_difference_type_t< D >>, end_fn > offs) &-> decltype(std::declval< Slice >()(std::declval< D &>(), offs.from, offs.to))
template<typename D = Derived, typename Slice = view::slice_fn, requires = (Same<D, Derived>())>
auto | operator[] (detail::slice_bounds< detail::from_end_< range_difference_type_t< D >>, end_fn > offs) const &-> decltype(std::declval< Slice >()(std::declval< D const &>(), offs.from, offs.to))
template<typename D = Derived, typename Slice = view::slice_fn, requires = (Same<D, Derived>())>
auto | operator[] (detail::slice_bounds< detail::from_end_< range_difference_type_t< D >>, end_fn > offs) &&-> decltype(std::declval< Slice >()(std::declval< D >(), offs.from, offs.to))
template<typename D = Derived, requires = (Same<D, Derived>() && Cardinality >= 0)>
constexpr range_size_type_t< D > | size () const noexcept
| Access the size of the range, if it can be determined:
template<typename D = Derived, requires = (Same<D, Derived>() && Cardinality < 0 && SizedSentinel<sentinel_t<D const>, iterator_t<D const>>() && ForwardRange<D const>())>
constexpr range_size_type_t< D > | size () const
| view_interface (view_interface &&)=default
| view_interface (view_interface const &)=default

## Protected Member Functions

Derived | begin_cursor () const
constexpr default_sentinel | end_cursor () const
Protected Member Functions inherited from ranges::v3::view_interface< Derived, Cardinality >
Derived & | derived () noexcept
constexpr Derived const & | derived () const noexcept

## Protected Attributes

friend | range_access

## Member Function Documentation

## begin() [1/2]

template<typename Derived, cardinality Cardinality>
template<typename D = Derived, requires = (Same<D, Derived>())>

detail::facade_iterator_t<D> ranges::v3::view_facade< Derived, Cardinality >::begin | ( |  | ) |

Let `d` be `static_cast<Derived &>(*this)`. Let `b` be `std::as_const(d).begin_cursor()` if that expression is well-formed; otherwise, let `b` be `d.begin_cursor()`. Let `B` be the type of `b`.

Returns
  `ranges::v3::basic_iterator<B>(b)`

Referenced by ranges::v3::intersperse_view< Rng >::size().

## begin() [2/2]

template<typename Derived, cardinality Cardinality>
template<typename D = Derived, requires = (Same<D, Derived>())>

detail::facade_iterator_t<D const> ranges::v3::view_facade< Derived, Cardinality >::begin | ( |  | ) | const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

## end() [1/2]

template<typename Derived, cardinality Cardinality>
template<typename D = Derived, requires = (Same<D, Derived>())>

detail::facade_sentinel_t<D> ranges::v3::view_facade< Derived, Cardinality >::end | ( |  | ) |

Let `d` be `static_cast<Derived &>(*this)`. Let `e` be `std::as_const(d).end_cursor()` if that expression is well-formed; otherwise, let `e` be `d.end_cursor()`. Let `E` be the type of `e`.

Returns
  `ranges::v3::basic_iterator<E>(e)` if `E` is the same as `B` computed above for `begin()`; otherwise, return `e`.

## end() [2/2]

template<typename Derived, cardinality Cardinality>
template<typename D = Derived, requires = (Same<D, Derived>())>

detail::facade_sentinel_t<D const> ranges::v3::view_facade< Derived, Cardinality >::end | ( |  | ) | const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.