std::ranges::view::iota, std::ranges::iota_view
template<WeaklyIncrementable W, Semiregular Bound = unreachable_sentinel_t> requires _WeaklyEqualityComparableWith<W, Bound> |
(1) | (since C++20) |
namespace view { inline constexpr /*unspecified*/ iota = /*unspecified*/; |
(2) | (since C++20) |
E
and F
Data members
std::ranges::iota_view::base_
W value_ = W(); /* exposition-only */ |
||
the current value
std::ranges::iota_view::pred_
Bound bound_ = Bound(); /* exposition-only */ |
||
the bound (defaults to std::unreachable_sentinel_t)
Member functions
std::ranges::iota_view::iota_view
iota_view() = default; |
(1) | |
constexpr explicit iota_view(W value); |
(2) | |
constexpr iota_view(std::type_identity_t<W> value, std::type_identity_t<Bound> bound); |
(3) | |
value_
and bound_
value_
with value and expects that Bound
is either unreachable_sentinel_t
(the default) or Bound() is reachable from value. This constructor is used to create unbounded iota views, e.g. iota(0) yields numbers 0,1,2..., infinitely.value_
with value and bound_
with bound
. This constructor is used to create bounded iota views, e.g. iota(10, 20) yields numbers from 10 to 19.Parameters
value | - | the starting value |
bound | - | the bound |
std::ranges::iota_view::begin
constexpr iterator begin(); |
||
Returns the iterator initialized with value_
std::ranges::iota_view::end
constexpr sentinel end() const; |
(1) | |
constexpr iterator end() const requires Same<W, Bound>; |
(2) | |
Returns the iterator initialized with bound_ if this view is bounded, or the sentinel initialized with bound_ if this view is unbounded.
std::ranges::iota_view::size
constexpr auto size() const requires (Same<W, Bound> && _Advanceable<W>) || |
||
Returns the size of the view if the view is bounded.
Deduction guides
Note that the guide protects itself against signed/unsigned mismatch bugs, like view::iota(0, v.size()), where 0 is a (signed) int and v.size() is an (unsigned) std::size_t.
Nested classes
std::ranges::iota_view::iterator
template<class W, class Bound> struct iota_view<W, Bound>::iterator /* exposition-only */ |
||
The return type of iota_view::begin
.
This is a RandomAccessIterator
if W models _Advanceable, a BidirectionalIterator
if W models _Decrementable, a ForwardIterator
if W models Incrementable
, and InputIterator
otherwise.
std::ranges::iota_view::iterator::iterator
constexpr explicit iterator(W value); |
||
Initializes exposition-only data member value_ with value. This value will be returned by operator* and incremented by operator++
std::ranges::iota_view::iterator::operator*
constexpr W operator*() const noexcept(is_nothrow_copy_constructible_v<W>); |
||
returns the current value, by value (in other words, this is a read-only view)
std::ranges::iota_view::iterator::operator++
constexpr iterator& operator++() |
||
Equivalent to
++value_; return *this;
std::ranges::iota_view::iterator::operator--
constexpr iterator& operator--() requires _Decrementable<W>; |
||
Equivalent to
--value_; return *this;
std::ranges::iota_view::iterator::operator[]
constexpr W operator[](difference_type n) const requires _Advanceable<W>; |
||
Equivalent to
return value_ + n;
Other members as expected of an iterator.
std::ranges::iota_view::sentinel
template<class W, class Bound> struct iota_view<W, Bound>::sentinel /* exposition-only */ |
||
The return type of iota_view::end
.
std::ranges::iota_view::sentinel::bound_
Bound bound_ = Bound();; /* exposition only */ |
||
Exposition-only data member holding the sentinel (typically either a number, for a bounded iota view, or an instance of std::unreachable_sentinel_t for an unbounded iota view.
std::ranges::iota_view::sentinel::sentinel
entinel() = default; constexpr explicit sentinel(Bound bound); |
||
Initializes exposition-only data member bound_ with bound.
std::ranges::iota_view::sentinel::operator==
friend constexpr bool operator==(const iterator& x, const sentinel& y); friend constexpr bool operator==(const sentinel& x, const iterator& y); |
||
Equivalent to: x.value_ == y.bound_; and return y == x; respectively.
std::ranges::iota_view::sentinel::operator!=
friend constexpr bool operator!=(const iterator& x, const sentinel& y); friend constexpr bool operator!=(const sentinel& x, const iterator& y); |
||
Equivalent to return !(x == y); and return !(y == x); respectively