[range.to.input.iterator]

# 25 Ranges library [[ranges]](./#ranges)

## 25.7 Range adaptors [[range.adaptors]](range.adaptors#range.to.input.iterator)

### 25.7.35 To input view [[range.to.input]](range.to.input#iterator)

#### 25.7.35.3 Class template to_input_view​::​*iterator* [range.to.input.iterator]

[🔗](#lib:to_input_view::iterator)

namespace std::ranges {template<[input_range](range.refinements#concept:input_range "25.4.6 Other range refinements [range.refinements]") V>requires [view](range.view#concept:view "25.4.5 Views [range.view]")<V>template<bool Const>class to_input_view<V>::*iterator* {using *Base* = *maybe-const*<Const, V>; // *exposition only* iterator_t<*Base*> *current_* = iterator_t<*Base*>(); // *exposition only*constexpr explicit *iterator*(iterator_t<*Base*> current); // *exposition only*public:using difference_type = range_difference_t<*Base*>; using value_type = range_value_t<*Base*>; using iterator_concept = input_iterator_tag; *iterator*() requires [default_initializable](concept.default.init#concept:default_initializable "18.4.12 Concept default_­initializable [concept.default.init]")<iterator_t<*Base*>> = default; *iterator*(*iterator*&&) = default; *iterator*& operator=(*iterator*&&) = default; constexpr *iterator*(*iterator*<!Const> i)requires Const && [convertible_to](concept.convertible#concept:convertible_to "18.4.4 Concept convertible_­to [concept.convertible]")<iterator_t<V>, iterator_t<*Base*>>; constexpr iterator_t<*Base*> base() &&; constexpr const iterator_t<*Base*>& base() const & noexcept; constexpr decltype(auto) operator*() const { return **current_*; }constexpr *iterator*& operator++(); constexpr void operator++(int); friend constexpr bool operator==(const *iterator*& x, const sentinel_t<*Base*>& y); friend constexpr difference_type operator-(const sentinel_t<*Base*>& y, const *iterator*& x)requires [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_­sentinel_­for [iterator.concept.sizedsentinel]")<sentinel_t<*Base*>, iterator_t<*Base*>>; friend constexpr difference_type operator-(const *iterator*& x, const sentinel_t<*Base*>& y)requires [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_­sentinel_­for [iterator.concept.sizedsentinel]")<sentinel_t<*Base*>, iterator_t<*Base*>>; friend constexpr range_rvalue_reference_t<*Base*> iter_move(const *iterator*& i)noexcept(noexcept(ranges::iter_move(i.*current_*))); friend constexpr void iter_swap(const *iterator*& x, const *iterator*& y)noexcept(noexcept(ranges::iter_swap(x.*current_*, y.*current_*)))requires [indirectly_swappable](alg.req.ind.swap#concept:indirectly_swappable "24.3.7.4 Concept indirectly_­swappable [alg.req.ind.swap]")<iterator_t<*Base*>>; };}

[🔗](#lib:to_input_view::iterator,constructor)

`constexpr explicit iterator(iterator_t<Base> current);
`

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L17912)

*Effects*: Initializes *current_* with std​::​move(current)[.](#1.sentence-1)

[🔗](#lib:to_input_view::iterator,constructor_)

`constexpr iterator(iterator<!Const> i)
  requires Const && [convertible_to](concept.convertible#concept:convertible_to "18.4.4 Concept convertible_­to [concept.convertible]")<iterator_t<V>, iterator_t<Base>>;
`

[2](#2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L17924)

*Effects*: Initializes *current_* with std​::​move(i.*current_*)[.](#2.sentence-1)

[🔗](#lib:base,to_input_view::iterator)

`constexpr iterator_t<Base> base() &&;
`

[3](#3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L17935)

*Returns*: std​::​move(*current_)*[.](#3.sentence-1)

[🔗](#lib:base,to_input_view::iterator_)

`constexpr const iterator_t<Base>& base() const & noexcept;
`

[4](#4)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L17946)

*Returns*: *current_*[.](#4.sentence-1)

[🔗](#lib:operator++,to_input_view::iterator)

`constexpr iterator& operator++();
`

[5](#5)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L17957)

*Effects*: Equivalent to:++*current_*;return *this;

[🔗](#lib:operator++,to_input_view::iterator_)

`constexpr void operator++(int);
`

[6](#6)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L17972)

*Effects*: Equivalent to: ++*this;

[🔗](#lib:operator==,to_input_view::iterator)

`friend constexpr bool operator==(const iterator& x, const sentinel_t<Base>& y);
`

[7](#7)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L17983)

*Returns*: x.*current_* == y[.](#7.sentence-1)

[🔗](#lib:operator-,to_input_view::iterator)

`friend constexpr difference_type operator-(const sentinel_t<Base>& y, const iterator& x)
  requires [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_­sentinel_­for [iterator.concept.sizedsentinel]")<sentinel_t<Base>, iterator_t<Base>>;
`

[8](#8)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L17995)

*Returns*: y - x.*current_*[.](#8.sentence-1)

[🔗](#lib:operator-,to_input_view::iterator_)

`friend constexpr difference_type operator-(const iterator& x, const sentinel_t<Base>& y)
  requires [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_­sentinel_­for [iterator.concept.sizedsentinel]")<sentinel_t<Base>, iterator_t<Base>>;
`

[9](#9)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L18007)

*Returns*: x.*current_* - y[.](#9.sentence-1)

[🔗](#lib:iter_move,to_input_view::iterator)

`friend constexpr range_rvalue_reference_t<Base> iter_move(const iterator& i)
  noexcept(noexcept(ranges::iter_move(i.current_)));
`

[10](#10)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L18019)

*Effects*: Equivalent to: return ranges​::​iter_move(i.*current_*);

[🔗](#lib:iter_swap,to_input_view::iterator)

`friend constexpr void iter_swap(const iterator& x, const iterator& y)
  noexcept(noexcept(ranges::iter_swap(x.current_, y.current_)))
  requires [indirectly_swappable](alg.req.ind.swap#concept:indirectly_swappable "24.3.7.4 Concept indirectly_­swappable [alg.req.ind.swap]")<iterator_t<Base>>;
`

[11](#11)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L18032)

*Effects*: Equivalent to: ranges​::​iter_swap(x.*current_*, y.*current_*);