[range.stride] # 25 Ranges library [[ranges]](./#ranges) ## 25.7 Range adaptors [[range.adaptors]](range.adaptors#range.stride) ### 25.7.32 Stride view [range.stride] #### [25.7.32.1](#overview) Overview [[range.stride.overview]](range.stride.overview) [1](#overview-1) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L15926) stride_view presents a view of an underlying sequence, advancing over n elements at a time, as opposed to the usual single-step succession[.](#overview-1.sentence-1) [2](#overview-2) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L15931) The name views​::​stride denotes a range adaptor object ([[range.adaptor.object]](range.adaptor.object "25.7.2 Range adaptor objects"))[.](#overview-2.sentence-1) Given subexpressions E and N, the expression views​::​stride(E, N) is expression-equivalent to stride_view(E, N)[.](#overview-2.sentence-2) [3](#overview-3) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L15938) [*Example [1](#overview-example-1)*: auto input = views::iota(0, 12) | views::stride(3); ranges::copy(input, ostream_iterator(cout, " ")); // prints 0 3 6 9 ranges::copy(input | views::reverse, ostream_iterator(cout, " ")); // prints 9 6 3 0 — *end example*] #### [25.7.32.2](#view) Class template stride_view [[range.stride.view]](range.stride.view) [🔗](#lib:stride_view) 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]")class stride_view : public view_interface> { V *base_*; // *exposition only* range_difference_t *stride_*; // *exposition only*// [[range.stride.iterator]](#iterator "25.7.32.3 Class template stride_­view​::​iterator"), class template stride_view​::​*iterator*template class *iterator*; // *exposition only*public:constexpr explicit stride_view(V base, range_difference_t stride); constexpr V base() const & requires [copy_constructible](concept.copyconstructible#concept:copy_constructible "18.4.14 Concept copy_­constructible [concept.copyconstructible]") { return *base_*; }constexpr V base() && { return std::move(*base_*); }constexpr range_difference_t stride() const noexcept; constexpr auto begin() requires (![*simple-view*](range.utility.helpers#concept:simple-view "25.5.2 Helper concepts [range.utility.helpers]")) {return *iterator*(this, ranges::begin(*base_*)); }constexpr auto begin() const requires [range](range.range#concept:range "25.4.2 Ranges [range.range]") {return *iterator*(this, ranges::begin(*base_*)); }constexpr auto end() requires (![*simple-view*](range.utility.helpers#concept:simple-view "25.5.2 Helper concepts [range.utility.helpers]")) {if constexpr ([common_range](range.refinements#concept:common_range "25.4.6 Other range refinements [range.refinements]") && [sized_range](range.sized#concept:sized_range "25.4.4 Sized ranges [range.sized]") && [forward_range](range.refinements#concept:forward_range "25.4.6 Other range refinements [range.refinements]")) {auto missing = (*stride_* - ranges::distance(*base_*) % *stride_*) % *stride_*; return *iterator*(this, ranges::end(*base_*), missing); } else if constexpr ([common_range](range.refinements#concept:common_range "25.4.6 Other range refinements [range.refinements]") && ![bidirectional_range](range.refinements#concept:bidirectional_range "25.4.6 Other range refinements [range.refinements]")) {return *iterator*(this, ranges::end(*base_*)); } else {return default_sentinel; }}constexpr auto end() const requires [range](range.range#concept:range "25.4.2 Ranges [range.range]") {if constexpr ([common_range](range.refinements#concept:common_range "25.4.6 Other range refinements [range.refinements]") && [sized_range](range.sized#concept:sized_range "25.4.4 Sized ranges [range.sized]") && [forward_range](range.refinements#concept:forward_range "25.4.6 Other range refinements [range.refinements]")) {auto missing = (*stride_* - ranges::distance(*base_*) % *stride_*) % *stride_*; return *iterator*(this, ranges::end(*base_*), missing); } else if constexpr ([common_range](range.refinements#concept:common_range "25.4.6 Other range refinements [range.refinements]") && ![bidirectional_range](range.refinements#concept:bidirectional_range "25.4.6 Other range refinements [range.refinements]")) {return *iterator*(this, ranges::end(*base_*)); } else {return default_sentinel; }}constexpr auto size() requires [sized_range](range.sized#concept:sized_range "25.4.4 Sized ranges [range.sized]"); constexpr auto size() const requires [sized_range](range.sized#concept:sized_range "25.4.4 Sized ranges [range.sized]"); constexpr auto reserve_hint() requires [approximately_sized_range](range.approximately.sized#concept:approximately_sized_range "25.4.3 Approximately sized ranges [range.approximately.sized]"); constexpr auto reserve_hint() const requires [approximately_sized_range](range.approximately.sized#concept:approximately_sized_range "25.4.3 Approximately sized ranges [range.approximately.sized]"); }; template stride_view(R&&, range_difference_t) -> stride_view>;} [🔗](#lib:stride_view,constructor) `constexpr stride_view(V base, range_difference_t stride); ` [1](#view-1) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16015) *Preconditions*: stride > 0 is true[.](#view-1.sentence-1) [2](#view-2) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16019) *Effects*: Initializes *base_* with std​::​move(base) and*stride_* with stride[.](#view-2.sentence-1) [🔗](#lib:stride,stride_view) `constexpr range_difference_t stride() const noexcept; ` [3](#view-3) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16031) *Returns*: *stride_*[.](#view-3.sentence-1) [🔗](#lib:size,stride_view) `constexpr auto size() requires [sized_range](range.sized#concept:sized_range "25.4.4 Sized ranges [range.sized]"); constexpr auto size() const requires [sized_range](range.sized#concept:sized_range "25.4.4 Sized ranges [range.sized]"); ` [4](#view-4) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16043) *Effects*: Equivalent to:return *to-unsigned-like*(*div-ceil*(ranges::distance(*base_*), *stride_*)); [🔗](#lib:reserve_hint,stride_view) `constexpr auto reserve_hint() requires [approximately_sized_range](range.approximately.sized#concept:approximately_sized_range "25.4.3 Approximately sized ranges [range.approximately.sized]"); constexpr auto reserve_hint() const requires [approximately_sized_range](range.approximately.sized#concept:approximately_sized_range "25.4.3 Approximately sized ranges [range.approximately.sized]"); ` [5](#view-5) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16058) *Effects*: Equivalent to:auto s = static_cast>(ranges::reserve_hint(*base_*));return *to-unsigned-like*(*div-ceil*(s, *stride_*)); #### [25.7.32.3](#iterator) Class template stride_view​::​*iterator* [[range.stride.iterator]](range.stride.iterator) [🔗](#lib:stride_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]")templateclass stride_view::*iterator* {using *Parent* = *maybe-const*; // *exposition only*using *Base* = *maybe-const*; // *exposition only* iterator_t<*Base*> *current_* = iterator_t<*Base*>(); // *exposition only* sentinel_t<*Base*> *end_* = sentinel_t<*Base*>(); // *exposition only* range_difference_t<*Base*> *stride_* = 0; // *exposition only* range_difference_t<*Base*> *missing_* = 0; // *exposition only*constexpr *iterator*(*Parent** parent, iterator_t<*Base*> current, // *exposition only* range_difference_t<*Base*> missing = 0); public:using difference_type = range_difference_t<*Base*>; using value_type = range_value_t<*Base*>; using iterator_concept = *see below*; using iterator_category = *see below*; // not always present*iterator*() requires [default_initializable](concept.default.init#concept:default_initializable "18.4.12 Concept default_­initializable [concept.default.init]")> = default; constexpr *iterator*(*iterator* other)requires Const && [convertible_to](concept.convertible#concept:convertible_to "18.4.4 Concept convertible_­to [concept.convertible]"), iterator_t<*Base*>>&& [convertible_to](concept.convertible#concept:convertible_to "18.4.4 Concept convertible_­to [concept.convertible]"), sentinel_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); constexpr *iterator* operator++(int) requires [forward_range](range.refinements#concept:forward_range "25.4.6 Other range refinements [range.refinements]")<*Base*>; constexpr *iterator*& operator--() requires [bidirectional_range](range.refinements#concept:bidirectional_range "25.4.6 Other range refinements [range.refinements]")<*Base*>; constexpr *iterator* operator--(int) requires [bidirectional_range](range.refinements#concept:bidirectional_range "25.4.6 Other range refinements [range.refinements]")<*Base*>; constexpr *iterator*& operator+=(difference_type n) requires [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]")<*Base*>; constexpr *iterator*& operator-=(difference_type n) requires [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]")<*Base*>; constexpr decltype(auto) operator[](difference_type n) constrequires [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]")<*Base*>{ return *(*this + n); }friend constexpr bool operator==(const *iterator*& x, default_sentinel_t); friend constexpr bool operator==(const *iterator*& x, const *iterator*& y)requires [equality_comparable](concept.equalitycomparable#concept:equality_comparable "18.5.4 Concept equality_­comparable [concept.equalitycomparable]")>; friend constexpr bool operator<(const *iterator*& x, const *iterator*& y)requires [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]")<*Base*>; friend constexpr bool operator>(const *iterator*& x, const *iterator*& y)requires [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]")<*Base*>; friend constexpr bool operator<=(const *iterator*& x, const *iterator*& y)requires [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]")<*Base*>; friend constexpr bool operator>=(const *iterator*& x, const *iterator*& y)requires [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]")<*Base*>; friend constexpr auto operator<=>(const *iterator*& x, const *iterator*& y)requires [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]")<*Base*> && [three_way_comparable](cmp.concept#concept:three_way_comparable "17.12.4 Concept three_­way_­comparable [cmp.concept]")>; friend constexpr *iterator* operator+(const *iterator*& x, difference_type n)requires [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]")<*Base*>; friend constexpr *iterator* operator+(difference_type n, const *iterator*& x)requires [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]")<*Base*>; friend constexpr *iterator* operator-(const *iterator*& x, difference_type n)requires [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]")<*Base*>; friend constexpr difference_type operator-(const *iterator*& x, const *iterator*& y)requires [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_­sentinel_­for [iterator.concept.sizedsentinel]"), iterator_t<*Base*>>; friend constexpr difference_type operator-(default_sentinel_t 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]"), iterator_t<*Base*>>; friend constexpr difference_type operator-(const *iterator*& x, default_sentinel_t y)requires [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_­sentinel_­for [iterator.concept.sizedsentinel]"), 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]")>; };} [1](#iterator-1) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16161) *iterator*​::​iterator_concept is defined as follows: - [(1.1)](#iterator-1.1) If *Base* models [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]"), then iterator_concept denotes random_access_iterator_tag[.](#iterator-1.1.sentence-1) - [(1.2)](#iterator-1.2) Otherwise, if *Base* models [bidirectional_range](range.refinements#concept:bidirectional_range "25.4.6 Other range refinements [range.refinements]"), then iterator_concept denotes bidirectional_iterator_tag[.](#iterator-1.2.sentence-1) - [(1.3)](#iterator-1.3) Otherwise, if *Base* models [forward_range](range.refinements#concept:forward_range "25.4.6 Other range refinements [range.refinements]"), then iterator_concept denotes forward_iterator_tag[.](#iterator-1.3.sentence-1) - [(1.4)](#iterator-1.4) Otherwise, iterator_concept denotes input_iterator_tag[.](#iterator-1.4.sentence-1) [2](#iterator-2) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16177) The member [*typedef-name*](dcl.typedef#nt:typedef-name "9.2.4 The typedef specifier [dcl.typedef]") iterator_category is defined if and only if *Base* models [forward_range](range.refinements#concept:forward_range "25.4.6 Other range refinements [range.refinements]")[.](#iterator-2.sentence-1) In that case,*iterator*​::​iterator_category is defined as follows: - [(2.1)](#iterator-2.1) Let C denote the type iterator_traits>​::​iterator_category[.](#iterator-2.1.sentence-1) - [(2.2)](#iterator-2.2) If C models[derived_from](concept.derived#concept:derived_from "18.4.3 Concept derived_­from [concept.derived]"), then iterator_category denotes random_access_iterator_tag[.](#iterator-2.2.sentence-1) - [(2.3)](#iterator-2.3) Otherwise, iterator_category denotes C[.](#iterator-2.3.sentence-1) [🔗](#lib:stride_view::iterator,constructor) `constexpr iterator(Parent* parent, iterator_t current, range_difference_t missing = 0); ` [3](#iterator-3) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16201) *Effects*: Initializes *current_* with std​::​move(current),*end_* with ranges​::​end(parent->*base_*),*stride_* with parent->*stride_*, and*missing_* with missing[.](#iterator-3.sentence-1) [🔗](#lib:stride_view::iterator,constructor_) `constexpr iterator(iterator i) requires Const && [convertible_to](concept.convertible#concept:convertible_to "18.4.4 Concept convertible_­to [concept.convertible]"), iterator_t> && [convertible_to](concept.convertible#concept:convertible_to "18.4.4 Concept convertible_­to [concept.convertible]"), sentinel_t>; ` [4](#iterator-4) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16217) *Effects*: Initializes *current_* with std​::​move(i.*current_*),*end_* with std​::​move(i.*end_*),*stride_* with i.*stride_*, and*missing_* with i.*missing_*[.](#iterator-4.sentence-1) [🔗](#lib:base,stride_view::iterator) `constexpr iterator_t base() &&; ` [5](#iterator-5) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16231) *Returns*: std​::​move(*current_*)[.](#iterator-5.sentence-1) [🔗](#lib:base,stride_view::iterator_) `constexpr const iterator_t& base() const & noexcept; ` [6](#iterator-6) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16242) *Returns*: *current_*[.](#iterator-6.sentence-1) [🔗](#lib:operator++,stride_view::iterator) `constexpr iterator& operator++(); ` [7](#iterator-7) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16253) *Preconditions*: *current_* != *end_* is true[.](#iterator-7.sentence-1) [8](#iterator-8) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16257) *Effects*: Equivalent to:*missing_* = ranges::advance(*current_*, *stride_*, *end_*);return *this; [🔗](#lib:operator++,stride_view::iterator_) `constexpr void operator++(int); ` [9](#iterator-9) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16272) *Effects*: Equivalent to ++*this; [🔗](#lib:operator++,stride_view::iterator__) `constexpr iterator operator++(int) requires [forward_range](range.refinements#concept:forward_range "25.4.6 Other range refinements [range.refinements]"); ` [10](#iterator-10) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16283) *Effects*: Equivalent to:auto tmp = *this;++*this;return tmp; [🔗](#lib:operator--,stride_view::iterator) `constexpr iterator& operator--() requires [bidirectional_range](range.refinements#concept:bidirectional_range "25.4.6 Other range refinements [range.refinements]"); ` [11](#iterator-11) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16299) *Effects*: Equivalent to:ranges::advance(*current_*, *missing_* - *stride_*);*missing_* = 0;return *this; [🔗](#lib:operator--,stride_view::iterator_) `constexpr iterator operator--(int) requires [bidirectional_range](range.refinements#concept:bidirectional_range "25.4.6 Other range refinements [range.refinements]"); ` [12](#iterator-12) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16315) *Effects*: Equivalent to:auto tmp = *this;--*this;return tmp; [🔗](#lib:operator+=,stride_view::iterator) `constexpr iterator& operator+=(difference_type n) requires [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]"); ` [13](#iterator-13) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16331) *Preconditions*: If n is positive,ranges​::​distance(*current_*, *end_*) > *stride_* * (n - 1) is true[.](#iterator-13.sentence-1) [*Note [1](#iterator-note-1)*: If n is negative, the *Effects* paragraph implies a precondition[.](#iterator-13.sentence-2) — *end note*] [14](#iterator-14) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16340) *Effects*: Equivalent to:if (n > 0) { ranges::advance(*current_*, *stride_* * (n - 1)); *missing_* = ranges::advance(*current_*, *stride_*, *end_*);} else if (n < 0) { ranges::advance(*current_*, *stride_* * n + *missing_*); *missing_* = 0;}return *this; [🔗](#lib:operator-=,stride_view::iterator) `constexpr iterator& operator-=(difference_type x) requires [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]"); ` [15](#iterator-15) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16362) *Effects*: Equivalent to: return *this += -x; [🔗](#lib:operator==,stride_view::iterator) `friend constexpr bool operator==(const iterator& x, default_sentinel_t); ` [16](#iterator-16) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16373) *Returns*: x.*current_* == x.*end_*[.](#iterator-16.sentence-1) [🔗](#lib:operator==,stride_view::iterator_) `friend constexpr bool operator==(const iterator& x, const iterator& y) requires [equality_comparable](concept.equalitycomparable#concept:equality_comparable "18.5.4 Concept equality_­comparable [concept.equalitycomparable]")>; ` [17](#iterator-17) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16385) *Returns*: x.*current_* == y.*current_*[.](#iterator-17.sentence-1) [🔗](#lib:operator%3c,stride_view::iterator) `friend constexpr bool operator<(const iterator& x, const iterator& y) requires [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]"); ` [18](#iterator-18) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16397) *Returns*: x.*current_* < y.*current_*[.](#iterator-18.sentence-1) [🔗](#lib:operator%3e,stride_view::iterator) `friend constexpr bool operator>(const iterator& x, const iterator& y) requires [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]"); ` [19](#iterator-19) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16409) *Effects*: Equivalent to: return y < x; [🔗](#lib:operator%3c=,stride_view::iterator) `friend constexpr bool operator<=(const iterator& x, const iterator& y) requires [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]"); ` [20](#iterator-20) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16421) *Effects*: Equivalent to: return !(y < x); [🔗](#lib:operator%3e=,stride_view::iterator) `friend constexpr bool operator>=(const iterator& x, const iterator& y) requires [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]"); ` [21](#iterator-21) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16433) *Effects*: Equivalent to: return !(x < y); [🔗](#lib:operator%3c=%3e,stride_view::iterator) `friend constexpr auto operator<=>(const iterator& x, const iterator& y) requires [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]") && [three_way_comparable](cmp.concept#concept:three_way_comparable "17.12.4 Concept three_­way_­comparable [cmp.concept]")>; ` [22](#iterator-22) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16445) *Returns*: x.*current_* <=> y.*current_*[.](#iterator-22.sentence-1) [🔗](#lib:operator+,stride_view::iterator) `friend constexpr iterator operator+(const iterator& i, difference_type n) requires [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]"); friend constexpr iterator operator+(difference_type n, const iterator& i) requires [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]"); ` [23](#iterator-23) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16459) *Effects*: Equivalent to:auto r = i; r += n;return r; [🔗](#lib:operator-,stride_view::iterator) `friend constexpr iterator operator-(const iterator& i, difference_type n) requires [random_access_range](range.refinements#concept:random_access_range "25.4.6 Other range refinements [range.refinements]"); ` [24](#iterator-24) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16476) *Effects*: Equivalent to:auto r = i; r -= n;return r; [🔗](#lib:operator-,stride_view::iterator_) `friend constexpr difference_type operator-(const iterator& x, const iterator& y) requires [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_­sentinel_­for [iterator.concept.sizedsentinel]"), iterator_t>; ` [25](#iterator-25) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16493) *Returns*: Let N be (x.*current_* - y.*current_*)[.](#iterator-25.sentence-1) - [(25.1)](#iterator-25.1) If *Base* models [forward_range](range.refinements#concept:forward_range "25.4.6 Other range refinements [range.refinements]"),(N + x.*missing_* - y.*missing_*) / x.*stride_*[.](#iterator-25.1.sentence-1) - [(25.2)](#iterator-25.2) Otherwise, if N is negative, -*div-ceil*(-N, x.*stride_*)[.](#iterator-25.2.sentence-1) - [(25.3)](#iterator-25.3) Otherwise, *div-ceil*(N, x.*stride_*)[.](#iterator-25.3.sentence-1) [🔗](#lib:operator-,stride_view::iterator__) `friend constexpr difference_type operator-(default_sentinel_t 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]"), iterator_t>; ` [26](#iterator-26) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16514) *Returns*: *div-ceil*(x.*end_* - x.*current_*, x.*stride_*)[.](#iterator-26.sentence-1) [🔗](#lib:operator-,stride_view::iterator___) `friend constexpr difference_type operator-(const iterator& x, default_sentinel_t y) requires [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_­sentinel_­for [iterator.concept.sizedsentinel]"), iterator_t>; ` [27](#iterator-27) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16526) *Effects*: Equivalent to: return -(y - x); [🔗](#lib:iter_move,stride_view::iterator) `friend constexpr range_rvalue_reference_t iter_move(const iterator& i) noexcept(noexcept(ranges::iter_move(i.current_))); ` [28](#iterator-28) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16538) *Effects*: Equivalent to: return ranges​::​iter_move(i.*current_*); [🔗](#lib:iter_swap,stride_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]")>; ` [29](#iterator-29) [#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/ranges.tex#L16551) *Effects*: Equivalent to:ranges​::​iter_swap(x.*current_*, y.*current_*);