[range.zip.sentinel]

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

## 25.7 Range adaptors [[range.adaptors]](range.adaptors#range.zip.sentinel)

### 25.7.25 Zip view [[range.zip]](range.zip#sentinel)

#### 25.7.25.4 Class template zip_view​::​*sentinel* [range.zip.sentinel]

[ð](#lib:zip_view::sentinel)

namespace std::ranges {template<[input_range](range.refinements#concept:input_range "25.4.6 Other range refinements [range.refinements]")... Views>requires ([view](range.view#concept:view "25.4.5 Views [range.view]")<Views> && ...) && (sizeof...(Views) > 0)template<bool Const>class zip_view<Views...>::*sentinel* { tuple<sentinel_t<*maybe-const*<Const, Views>>...> *end_*; // *exposition only*constexpr explicit *sentinel*(tuple<sentinel_t<*maybe-const*<Const, Views>>...> end); // *exposition only*public:*sentinel*() = default; constexpr *sentinel*(*sentinel*<!Const> i)requires Const && ([convertible_to](concept.convertible#concept:convertible_to "18.4.4 Concept convertible_­to [concept.convertible]")<sentinel_t<Views>, sentinel_t<const Views>> && ...); template<bool OtherConst>requires ([sentinel_for](iterator.concept.sentinel#concept:sentinel_for "24.3.4.7 Concept sentinel_­for [iterator.concept.sentinel]")<sentinel_t<*maybe-const*<Const, Views>>,
 iterator_t<*maybe-const*<OtherConst, Views>>> && ...)friend constexpr bool operator==(const *iterator*<OtherConst>& x, const *sentinel*& y); template<bool OtherConst>requires ([sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_­sentinel_­for [iterator.concept.sizedsentinel]")<sentinel_t<*maybe-const*<Const, Views>>,
 iterator_t<*maybe-const*<OtherConst, Views>>> && ...)friend constexpr common_type_t<range_difference_t<*maybe-const*<OtherConst, Views>>...>operator-(const *iterator*<OtherConst>& x, const *sentinel*& y); template<bool OtherConst>requires ([sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_­sentinel_­for [iterator.concept.sizedsentinel]")<sentinel_t<*maybe-const*<Const, Views>>,
 iterator_t<*maybe-const*<OtherConst, Views>>> && ...)friend constexpr common_type_t<range_difference_t<*maybe-const*<OtherConst, Views>>...>operator-(const *sentinel*& y, const *iterator*<OtherConst>& x); };}

[ð](#lib:zip_view::sentinel,constructor)

`constexpr explicit sentinel(tuple<sentinel_t<maybe-const<Const, Views>>...> end);
`

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L11910)

*Effects*: Initializes *end_* with end[.](#1.sentence-1)

[ð](#lib:zip_view::sentinel,constructor_)

`constexpr sentinel(sentinel<!Const> i)
  requires Const && ([convertible_to](concept.convertible#concept:convertible_to "18.4.4 Concept convertible_­to [concept.convertible]")<sentinel_t<Views>, sentinel_t<const Views>> && ...);
`

[2](#2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L11922)

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

[ð](#lib:operator==,zip_view::sentinel)

`template<bool OtherConst>
  requires ([sentinel_for](iterator.concept.sentinel#concept:sentinel_for "24.3.4.7 Concept sentinel_­for [iterator.concept.sentinel]")<sentinel_t<maybe-const<Const, Views>>,
                         iterator_t<maybe-const<OtherConst, Views>>> && ...)
friend constexpr bool operator==(const iterator<OtherConst>& x, const sentinel& y);
`

[3](#3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L11936)

*Returns*: true if there exists an integer 0â¤i<sizeof...(Views) such that bool(std​::​get<i>(x.​*current_*) == std​::​get<i>(y.*end_*)) is true[.](#3.sentence-1)

Otherwise, false[.](#3.sentence-2)

[ð](#lib:operator-,zip_view::sentinel)

`template<bool OtherConst>
  requires ([sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_­sentinel_­for [iterator.concept.sizedsentinel]")<sentinel_t<maybe-const<Const, Views>>,
                               iterator_t<maybe-const<OtherConst, Views>>> && ...)
friend constexpr common_type_t<range_difference_t<maybe-const<OtherConst, Views>>...>
  operator-(const iterator<OtherConst>& x, const sentinel& y);
`

[4](#4)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L11954)

Let D be the return type[.](#4.sentence-1)

Let *DIST*(i) beD(std​::​get<i>(x.*current_*) - std​::​get<i>(y.*end_*))[.](#4.sentence-2)

[5](#5)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L11959)

*Returns*: The value with the smallest absolute value among *DIST*(n) for all integers 0â¤n<sizeof...(Views)[.](#5.sentence-1)

[ð](#lib:operator-,zip_view::sentinel_)

`template<bool OtherConst>
  requires ([sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_­sentinel_­for [iterator.concept.sizedsentinel]")<sentinel_t<maybe-const<Const, Views>>,
                               iterator_t<maybe-const<OtherConst, Views>>> && ...)
friend constexpr common_type_t<range_difference_t<maybe-const<OtherConst, Views>>...>
  operator-(const sentinel& y, const iterator<OtherConst>& x);
`

[6](#6)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L11975)

*Effects*: Equivalent to: return -(x - y);
