#include "view/enumerate.hpp"
#pragma once #include <concepts> #include <ranges> #include "internal/type_traits.hpp" #include "internal/ranges.hpp" namespace uni { namespace internal { template<class Range> concept range_with_movable_reference = std::ranges::input_range<Range> && std::move_constructible<std::ranges::range_reference_t<Range>> && std::move_constructible<std::ranges::range_rvalue_reference_t<Range>>; } // namespace internal template<std::ranges::view View> requires internal::range_with_movable_reference<View> struct enumerate_view : public std::ranges::view_interface<enumerate_view<View>> { private: View _base = View(); template<bool Const> class iterator; template<bool Const> class sentinel; public: enumerate_view() requires std::default_initializable<View> = default; constexpr explicit enumerate_view(View base) : _base(std::move(base)) {} constexpr auto begin() requires(!internal::simple_view<View>) { return iterator<false>(std::ranges::begin(this->_base), 0); } constexpr auto begin() const requires internal::range_with_movable_reference<const View> { return iterator<true>(std::ranges::begin(this->_base), 0); } constexpr auto end() requires(!internal::simple_view<View>) { if constexpr(std::ranges::common_range<View> && std::ranges::sized_range<View>) { return iterator<false>(std::ranges::end(_base), std::ranges::distance(this->_base)); } else { return sentinel<false>(std::ranges::end(_base)); } } constexpr auto end() const requires internal::range_with_movable_reference<const View> { if constexpr(std::ranges::common_range<const View> && std::ranges::sized_range<const View>) { return iterator<true>(std::ranges::end(_base), std::ranges::distance(_base)); } else { return sentinel<true>(std::ranges::end(_base)); } } constexpr auto size() requires std::ranges::sized_range<View> { return std::ranges::size(_base); } constexpr auto size() const requires std::ranges::sized_range<const View> { return std::ranges::size(_base); } constexpr View base() const & requires std::copy_constructible<View> { return _base; } constexpr View base() && { return std::move(_base); } }; template<class Range> enumerate_view(Range&& ) -> enumerate_view<std::views::all_t<Range>>; template<std::ranges::view View> requires internal::range_with_movable_reference<View> template<bool Const> class enumerate_view<View>::iterator { using Base = internal::maybe_const_t<Const, View>; friend enumerate_view; public: using iterator_category = std::iterator_traits<std::ranges::iterator_t<Base>>::iterator_category; using iterator_concept = internal::most_primitive_iterator_concept<Const, View>; using difference_type = std::ranges::range_difference_t<Base>; using value_type = std::tuple<difference_type, std::ranges::range_value_t<Base>>; private: using rangeeference_type = std::tuple<difference_type, std::ranges::range_reference_t<Base>>; std::ranges::iterator_t<Base> _current = std::ranges::iterator_t<Base>(); difference_type _pos = 0; constexpr explicit iterator(std::ranges::iterator_t<Base> current, const difference_type pos) : _current(std::move(current)), _pos(pos) {} public: iterator() requires std::default_initializable<std::ranges::iterator_t<Base>> = default; constexpr iterator(iterator<!Const> itr) requires Const && std::convertible_to<std::ranges::iterator_t<View>, std::ranges::iterator_t<Base>> : _current(std::move(itr._current)), _pos(itr._pos) {} constexpr const std::ranges::iterator_t<Base>& base() const & noexcept { return this->_current; } constexpr std::ranges::iterator_t<Base> base() && { return std::move(this->_current); } constexpr difference_type index() const noexcept { return this->_pos; } constexpr auto operator*() const { return rangeeference_type(this->_pos, *this->_current); } constexpr iterator& operator++() { ++this->_current; ++this->_pos; return *this; } constexpr void operator++(int) { ++*this; } constexpr iterator operator++(int) requires std::ranges::forward_range<Base> { auto temp = *this; ++*this; return temp; } constexpr iterator& operator--() requires std::ranges::bidirectional_range<Base> { --this->_current; --this->_pos; return *this; } constexpr iterator operator--(int) requires std::ranges::bidirectional_range<Base> { auto temp = *this; --*this; return temp; } constexpr iterator& operator+=(const difference_type diff) requires std::ranges::random_access_range<Base> { this->_current += diff; this->_pos += diff; return *this; } constexpr iterator& operator-=(const difference_type diff) requires std::ranges::random_access_range<Base> { this->_current -= diff; this->_pos -= diff; return *this; } constexpr auto operator[](const difference_type diff) const requires std::ranges::random_access_range<Base> { return rangeeference_type(this->_pos + diff, this->_current[diff]); } friend constexpr bool operator==(const iterator& lhs, const iterator& rhs) noexcept { return lhs._pos == rhs._pos; } friend constexpr std::strong_ordering operator<=>(const iterator& lhs, const iterator& rhs) noexcept { return lhs._pos <=> rhs._pos; } friend constexpr iterator operator+(iterator lhs, const difference_type rhs) requires std::ranges::random_access_range<Base> { return (lhs += rhs); } friend constexpr iterator operator+(const difference_type lhs, const iterator& rhs) requires std::ranges::random_access_range<Base> { return rhs += lhs; } friend constexpr iterator operator-(iterator& lhs, const difference_type rhs) requires std::ranges::random_access_range<Base> { return lhs -= rhs; } friend constexpr difference_type operator-(const iterator& lhs, const iterator& rhs) { return lhs._pos - rhs._pos; } friend constexpr auto iter_move(const iterator& itr) noexcept( noexcept (std::ranges::iter_move(itr._current)) && std::is_nothrow_move_constructible_v<std::ranges::range_rvalue_reference_t<Base>> ) { return std::tuple<difference_type, std::ranges::range_rvalue_reference_t<Base>>( itr._pos, std::ranges::iter_move(itr._current) ); } }; template<std::ranges::view View> requires internal::range_with_movable_reference<View> template<bool Const> class enumerate_view<View>::sentinel { using Base = internal::maybe_const_t<Const, View>; std::ranges::sentinel_t<Base> _end = std::ranges::sentinel_t<Base>(); constexpr explicit sentinel(std::ranges::sentinel_t<Base> end) : _end(std::move(end)) {} friend enumerate_view; public: sentinel() = default; constexpr sentinel(sentinel<!Const> other) requires Const && std::convertible_to<std::ranges::sentinel_t<View>, std::ranges::sentinel_t<Base>> : _end(std::move(other._end)) {} constexpr std::ranges::sentinel_t<Base> base() const { return this->_end; } template<bool Const_> requires std::sentinel_for< std::ranges::sentinel_t<Base>, std::ranges::iterator_t<internal::maybe_const_t<Const_, View>> > friend constexpr bool operator==(const iterator<Const_>& lhs, const sentinel& rhs) { return lhs._current == rhs._end; } template<bool Const_> requires std::sized_sentinel_for< std::ranges::sentinel_t<Base>, std::ranges::iterator_t<internal::maybe_const_t<Const_, View>> > friend constexpr std::ranges::range_difference_t<internal::maybe_const_t<Const_, View>> operator-(const iterator<Const_>& lhs, const sentinel& rhs) { return lhs._current - rhs._end; } template<bool Const_> requires std::sized_sentinel_for< std::ranges::sentinel_t<Base>, std::ranges::iterator_t<internal::maybe_const_t<Const_, View>>> friend constexpr std::ranges::range_difference_t<internal::maybe_const_t<Const_, View>> operator-(const sentinel& lhs, const iterator<Const_>& rhs) { return lhs._end - rhs._current; } }; namespace views { namespace internal { template<class T> concept can_enumerate_view = requires { enumerate_view<std::views::all_t<T>>(std::declval<T>()); }; } // namespace internal struct Enumerate : adaptor::range_adaptor_closure<Enumerate> { template<std::ranges::viewable_range Range> requires internal::can_enumerate_view<Range> constexpr auto operator() [[nodiscard]] (Range&& range) const { return enumerate_view<std::views::all_t<Range>>(std::forward<Range>(range)); } }; inline constexpr Enumerate enumerate; } // namespace views } // namespace uni namespace std::ranges { template<class T> inline constexpr bool enable_borrowed_range<uni::enumerate_view<T>> = enable_borrowed_range<T>; } // namespace std
#line 2 "view/enumerate.hpp" #include <concepts> #include <ranges> #line 2 "internal/type_traits.hpp" #include <iostream> #include <vector> #include <type_traits> #include <algorithm> #include <utility> #line 2 "internal/dev_env.hpp" #ifdef LOCAL_JUDGE inline constexpr bool DEV_ENV = true; inline constexpr bool NO_EXCEPT = false; #else inline constexpr bool DEV_ENV = false; inline constexpr bool NO_EXCEPT = true; #endif // LOCAL_JUDGE #if __cplusplus >= 202100L #define CPP20 true #define CPP23 true #elif __cplusplus >= 202002L #define CPP20 true #define CPP23 false #else #define CPP20 false #define CPP23 false #endif #line 12 "internal/type_traits.hpp" namespace uni { namespace internal { template<class... Ts> struct tuple_or_pair { using type = std::tuple<Ts...>; }; template<class T, class U> struct tuple_or_pair<T,U> { using type = std::pair<T, U>; }; template <class... Ts> using tuple_or_pair_t = typename tuple_or_pair<Ts...>::type; template<class T> constexpr std::underlying_type_t<T> to_underlying(const T& v) noexcept(NO_EXCEPT) { return static_cast<std::underlying_type_t<T>>(v); } template<class T, class... Ts> using are_same = std::conjunction<std::is_same<T, Ts>...>; template<class T, class... Ts> inline constexpr bool are_same_v = are_same<T, Ts...>::value; template<class T, class... Ts> using is_same_as_any_of = std::disjunction<std::is_same<T, Ts>...>; template<class T, class... Ts> inline constexpr bool is_same_as_any_of_v = is_same_as_any_of<T, Ts...>::value; template<class T, class... Ts> concept same_as_any_of = is_same_as_any_of_v<T, Ts...>; template<class Base, class... Derived> using is_base_of_all = std::conjunction<std::is_base_of<Base, Derived>...>; template<class Base, class... Derived> inline constexpr bool is_base_of_all_v = is_base_of_all<Base, Derived...>::value; template<class Base, class... Derived> using is_base_of_any = std::disjunction<std::is_base_of<Base, Derived>...>; template<class Base, class... Derived> inline constexpr bool is_base_of_any_v = is_base_of_any<Base, Derived...>::value; template<class T> struct remove_cvref { using type = typename std::remove_cv_t<std::remove_reference_t<T>>; }; template<class T> using remove_cvref_t = typename remove_cvref<T>::type; template<class T> struct literal_operator { static constexpr const char* value = ""; }; template<> struct literal_operator<unsigned> { static constexpr const char* value = "U"; }; template<> struct literal_operator<long> { static constexpr const char* value = "L"; }; template<> struct literal_operator<unsigned long> { static constexpr const char* value = "UL"; }; template<> struct literal_operator<long long> { static constexpr const char* value = "LL"; }; template<> struct literal_operator<unsigned long long> { static constexpr const char* value = "ULL"; }; template<> struct literal_operator<float> { static constexpr const char* value = "F"; }; template<> struct literal_operator<double> { static constexpr const char* value = "D"; }; template<> struct literal_operator<long double> { static constexpr const char* value = "LD"; }; #ifdef __SIZEOF_INT128__ template<> struct literal_operator<__int128_t> { static constexpr const char* value = "LLL"; }; template<> struct literal_operator<__uint128_t> { static constexpr const char* value = "ULLL"; }; #endif template<class T> inline constexpr auto literal_operator_v = literal_operator<T>::value; template <std::size_t N, typename... Types> struct nth_type {}; template <class Head, class... Tail> struct nth_type<0, Head, Tail...> { using type = Head; }; template <std::size_t N, class Head, class... Tail> struct nth_type<N, Head, Tail...> : public nth_type<N - 1, Tail...> {}; template <std::size_t N, typename... Types> using nth_type_t = typename nth_type<N, Types...>::type; template<template <class...> class, class> struct is_template_of : std::false_type {}; template<template <class...> class Template, class... Args> struct is_template_of<Template, Template<Args...>> : std::true_type {}; template<template <class...> class Template, class Type> inline constexpr bool is_template_of_v = is_template_of<Template, Type>::value; template<class Type, template <class...> class Template> concept substituted_from = is_template_of_v<Template, Type>; template<template <class...> class Base, class Derived> struct _is_basic_tempalte_of { template<class... Ts> static constexpr std::true_type test(const Base<Ts...> *); static constexpr std::false_type test(...); using type = decltype(test(std::declval<Derived*>())); }; template<template <class...> class Base, class Derived> using is_basic_tempalte_of = _is_basic_tempalte_of<Base, Derived>::type; template<template <class...> class Base, class Derived> inline constexpr bool is_basic_tempalte_of_v = is_basic_tempalte_of<Base, Derived>::value; template<class Derived, template <class...> class Base> concept derived_from_template = is_basic_tempalte_of_v<Base, Derived>; template<class T> struct is_loggable { template<class U> static constexpr auto External(U &&v) -> decltype(_debug(v), std::true_type()); static constexpr std::false_type External(...); template<class U> static constexpr auto Member(U &&v) -> decltype(v._debug(), std::true_type()); static constexpr std::false_type Member(...); static constexpr bool value = ( decltype(External(std::declval<T>()))::value || decltype(Member(std::declval<T>()))::value ); }; template<class T> inline constexpr auto is_loggable_v = is_loggable<T>::value; template<class T> concept loggable = is_loggable_v<T>; template<class T> struct _has_iterator { template<class U> static constexpr auto ADL(U &&v) -> decltype(begin(v), end(v), std::true_type()); static constexpr std::false_type ADL(...); template<class U> static constexpr auto STL(U &&v) -> decltype(std::begin(v), std::end(v), std::true_type()); static constexpr std::false_type STL(...); template<class U> static constexpr auto Member(U &&v) -> decltype(v.begin(), v.end(), std::true_type()); static constexpr std::false_type Member(...); }; template<class T> struct has_iterator { struct ADL : decltype(_has_iterator<T>::ADL(std::declval<T>())) {}; struct STL : decltype(_has_iterator<T>::STL(std::declval<T>())) {}; struct Member : decltype(_has_iterator<T>::Member(std::declval<T>())) {}; static constexpr auto adl_v = ADL::value; static constexpr auto stl_v = STL::value; static constexpr auto member_v = Member::value; }; template<class T> struct is_iterable { static constexpr bool value = has_iterator<T>::adl_v || has_iterator<T>::stl_v || has_iterator<T>::member_v; }; template<class T> inline constexpr auto is_iterable_v = is_iterable<T>::value; template<class T> concept iterable = is_iterable_v<T>; namespace iterator_resolver { template<class T> inline constexpr auto begin(T&& v) noexcept(NO_EXCEPT) { static_assert(is_iterable_v<T>); if constexpr(has_iterator<T>::member_v) { return v.begin(); } else { // ADL using std::begin; return begin(std::forward<T>(v)); } } template<class T> inline constexpr auto end(T&& v) noexcept(NO_EXCEPT) { static_assert(is_iterable_v<T>); if constexpr(has_iterator<T>::member_v) { return v.end(); } else { // ADL using std::end; return end(std::forward<T>(v)); } } }; template<class C> using iterator_t = decltype(iterator_resolver::begin(std::declval<C&>())); template<class C> using container_size_t = decltype(std::size(std::declval<C&>())); template<bool Const, class T> using maybe_const_t = std::conditional_t<Const, const T, T>; template<class T> using with_ref = T&; template<class T> concept can_reference = requires { typename with_ref<T>; }; } // namespace internal } // namespace uni #line 2 "internal/ranges.hpp" #line 6 "internal/ranges.hpp" #include <tuple> #line 11 "internal/ranges.hpp" namespace uni { namespace internal { template<class Range> concept resizable_range = std::ranges::range<Range> && requires (Range& r) { r.resize(0); }; template<class range> concept simple_view = std::ranges::view<range> && std::ranges::range<const range> && std::same_as<std::ranges::iterator_t<range>, std::ranges::iterator_t<const range>> && std::same_as<std::ranges::sentinel_t<range>, std::ranges::sentinel_t<const range>>; template<class... Ranges> concept zip_is_common = (sizeof...(Ranges) == 1 && (std::ranges::common_range<Ranges> && ...)) || (!(std::ranges::bidirectional_range<Ranges> && ...) && (std::ranges::common_range<Ranges> && ...)) || ((std::ranges::random_access_range<Ranges> && ...) && (std::ranges::sized_range<Ranges> && ...)); template<bool Const, class... Views> concept all_contiguous = (std::ranges::contiguous_range<maybe_const_t<Const, Views>> && ...); template<bool Const, class... Views> concept all_random_access = (std::ranges::random_access_range<maybe_const_t<Const, Views>> && ...); template<bool Const, class... Views> concept all_bidirectional = (std::ranges::bidirectional_range<maybe_const_t<Const, Views>> && ...); template<bool Const, class... Views> concept all_forward = (std::ranges::forward_range<maybe_const_t<Const, Views>> && ...); template<bool Const, class... Views> struct zip_view_iterator_category {}; template<bool Const, class... Views> requires all_forward<Const, Views...> struct zip_view_iterator_category<Const, Views...> { using iterator_category = std::input_iterator_tag; }; template<bool Const, class... Views> static auto _most_primitive_iterator_concept() noexcept(NO_EXCEPT) { if constexpr(all_random_access<Const, Views...>) return std::random_access_iterator_tag{}; else if constexpr(all_bidirectional<Const, Views...>) return std::bidirectional_iterator_tag{}; else if constexpr(all_forward<Const, Views...>) return std::forward_iterator_tag{}; else return std::input_iterator_tag{}; } template<bool Const, class... Views> using most_primitive_iterator_concept = decltype(_most_primitive_iterator_concept<Const, Views...>()); template<class Range, bool Const> using range_iterator_category = typename std::iterator_traits< std::ranges::iterator_t<maybe_const_t<Const, Range>> >::iterator_category; template<class Range> static constexpr auto _iterator_concept() noexcept(NO_EXCEPT) { if constexpr(std::ranges::random_access_range<Range>) return std::random_access_iterator_tag{}; else if constexpr(std::ranges::bidirectional_range<Range>) return std::bidirectional_iterator_tag{}; else if constexpr(std::ranges::forward_range<Range>) return std::forward_iterator_tag{}; else return std::input_iterator_tag{}; } template<class Range> using iterator_concept = decltype(_iterator_concept<Range>()); template<std::ranges::range Range> struct cached_position { constexpr bool has_value() const { return false; } constexpr std::ranges::iterator_t<Range> get(const Range&) const { __builtin_unreachable(); } constexpr void set(const Range &, const std::ranges::iterator_t<Range> &) const {} }; template<std::ranges::forward_range Range> struct cached_position<Range> : protected std::optional<std::ranges::iterator_t<Range>> { using std::optional<std::ranges::iterator_t<Range>>::optioanl; using std::optional<std::ranges::iterator_t<Range>>::has_value; constexpr std::ranges::iterator_t<Range> get(const Range&) const { assert(this->has_value()); return **this; } constexpr void set(const Range&, const std::ranges::iterator_t<Range>& itr) { assert(!this->has_value()); this->emplace(*itr); } }; template<std::ranges::random_access_range Range> requires(sizeof(std::ranges::range_difference_t<Range>) <= sizeof(std::ranges::iterator_t<Range>)) struct cached_position<Range> { private: std::ranges::range_difference_t<Range> _offset = -1; public: cached_position() = default; constexpr cached_position(const cached_position &) = default; constexpr cached_position(cached_position &&other) noexcept { *this = std::move(other); } constexpr cached_position &operator=(const cached_position &) = default; constexpr cached_position &operator=(cached_position &&other) noexcept { // Propagate the cached offset, but invalidate the source. this->_offset = other._offset; other._offset = -1; return *this; } constexpr bool has_value() const { return this->_offset >= 0; } constexpr std::ranges::iterator_t<Range> get(Range& range) const { assert(this->has_value()); return std::ranges::begin(range) + this->_offset; } constexpr void set(Range &range, const std::ranges::iterator_t<Range> &itr) { assert(!this->has_value()); this->_offset = itr - std::ranges::begin(range); } }; template<typename T, int Disc> struct absent { }; template<bool PRESENT, class T, int Disc = 0> using maybe_present_t = std::conditional_t<PRESENT, T, absent<T, Disc>>; } // namespace internal namespace views::adaptor { template<class Adaptor, class... Args> concept adaptor_invocable = requires { std::declval<Adaptor>()(std::declval<Args>()...); }; template<class Adaptor, class... Args> concept adaptor_partial_app_viable = (Adaptor::arity > 1) && (sizeof...(Args) == Adaptor::arity - 1) && (std::constructible_from<std::remove_cvref_t<Args>, Args> && ...); template<class Adaptor, class... Args> struct partial; template<class, class> struct pipe; template<class Derived> struct range_adaptor_closure {}; template<class T, class U> requires(!std::same_as<T, range_adaptor_closure<U>>) void is_range_adaptor_closure_fn(const T &, const range_adaptor_closure<U> &); template<class T> concept is_range_adaptor_closure = requires(T t) { adaptor::is_range_adaptor_closure_fn(t, t); }; template<class Self, class Range> requires is_range_adaptor_closure<Self> && adaptor_invocable<Self, Range> constexpr auto operator|(Range&& range, Self&& self) { return std::forward<Self>(self)(std::forward<Range>(range)); } template<class Lhs, class Rhs> requires is_range_adaptor_closure<Lhs> && is_range_adaptor_closure<Rhs> constexpr auto operator|(Lhs&& lhs, Rhs&& rhs) { return pipe<std::remove_cvref_t<Lhs>, std::remove_cvref_t<Rhs>>{ std::forward<Lhs>(lhs), std::forward<Rhs>(rhs)}; } template<class Derived> struct range_adaptor { template<class... Args> requires adaptor_partial_app_viable<Derived, Args...> inline constexpr auto operator()(Args&& ..._args) const noexcept(NO_EXCEPT) { return partial<Derived, std::remove_cvref_t<Args>...>{ std::forward<Args>(_args)... }; } }; template<class Adaptor> concept closure_has_simple_call_op = Adaptor::has_simple_call_op; template<class Adaptor, class... Args> concept adaptor_has_simple_extra_args = Adaptor::has_simple_extra_args || Adaptor::template has_simple_extra_args<Args...>; template<class Adaptor, class... Args> struct partial : range_adaptor_closure<partial<Adaptor, Args...>> { std::tuple<Args...> args; constexpr partial(Args... _args) noexcept(NO_EXCEPT) : args(std::move(_args)...) {} template<class Range> requires adaptor_invocable<Adaptor, Range, const Args &...> inline constexpr auto operator()(Range&& range) const & noexcept(NO_EXCEPT) { const auto forwarder = [&range](const auto &..._args) constexpr noexcept(NO_EXCEPT) { return Adaptor{}(std::forward<Range>(range), _args...); }; return std::apply(forwarder, this->args); } template<class Range> requires adaptor_invocable<Adaptor, Range, Args...> inline constexpr auto operator()(Range&& range) && noexcept(NO_EXCEPT) { const auto forwarder = [&range](auto &..._args) constexpr noexcept(NO_EXCEPT) { return Adaptor{}(std::forward<Range>(range), std::move(_args)...); }; return std::apply(forwarder, this->args); } template<class Range> inline constexpr auto operator()(Range&& range) const && = delete; }; template<class Adaptor, class Arg> struct partial<Adaptor, Arg> : range_adaptor_closure<partial<Adaptor, Arg>> { Arg arg; constexpr partial(Arg _arg) noexcept(NO_EXCEPT) : arg(std::move(_arg)) {} template<class Range> requires adaptor_invocable<Adaptor, Range, const Arg &> inline constexpr auto operator()(Range&& range) const & noexcept(NO_EXCEPT) { return Adaptor{}(std::forward<Range>(range), this->arg); } template<class Range> requires adaptor_invocable<Adaptor, Range, Arg> inline constexpr auto operator()(Range&& range) && noexcept(NO_EXCEPT) { return Adaptor{}(std::forward<Range>(range), std::move(this->arg)); } template<class Range> inline constexpr auto operator()(Range&& range) const && = delete; }; template<class Adaptor, class... Args> requires adaptor_has_simple_extra_args<Adaptor, Args...> && (std::is_trivially_copyable_v<Args> && ...) struct partial<Adaptor, Args...> : range_adaptor_closure<partial<Adaptor, Args...>> { std::tuple<Args...> args; constexpr partial(Args... _args) noexcept(NO_EXCEPT) : args(std::move(_args)...) {} template<class Range> requires adaptor_invocable<Adaptor, Range, const Args &...> inline constexpr auto operator()(Range&& range) const noexcept(NO_EXCEPT) { const auto forwarder = [&range](const auto &..._args) constexpr noexcept(NO_EXCEPT) { return Adaptor{}(std::forward<Range>(range), _args...); }; return std::apply(forwarder, this->args); } static constexpr bool has_simple_call_op = true; }; template<class Adaptor, class Arg> requires adaptor_has_simple_extra_args<Adaptor, Arg> && std::is_trivially_copyable_v<Arg> struct partial<Adaptor, Arg> : range_adaptor_closure<partial<Adaptor, Arg>> { Arg arg; constexpr partial(Arg _arg) noexcept(NO_EXCEPT) : arg(std::move(_arg)) {} template<class Range> requires adaptor_invocable<Adaptor, Range, const Arg &> inline constexpr auto operator()(Range&& range) const noexcept(NO_EXCEPT) { return Adaptor{}(std::forward<Range>(range), this->arg); } static constexpr bool has_simple_call_op = true; }; template<class Lhs, class Rhs, class Range> concept pipe_invocable = requires { std::declval<Rhs>()(std::declval<Lhs>()(std::declval<Range>())); }; template<class Lhs, class Rhs> struct pipe : range_adaptor_closure<pipe<Lhs, Rhs>> { [[no_unique_address]] Lhs lhs; [[no_unique_address]] Rhs rhs; constexpr pipe(Lhs _lhs, Rhs _rhs) noexcept(NO_EXCEPT) : lhs(std::move(_lhs)), rhs(std::move(_rhs)) {} template<class Range> requires pipe_invocable<const Lhs &, const Rhs &, Range> inline constexpr auto operator()(Range&& range) const & noexcept(NO_EXCEPT) { return rhs(lhs(std::forward<Range>(range))); } template<class Range> requires pipe_invocable<Lhs, Rhs, Range> inline constexpr auto operator()(Range&& range) && noexcept(NO_EXCEPT) { return std::move(rhs)(std::move(lhs)(std::forward<Range>(range))); } template<class Range> inline constexpr auto operator()(Range&& range) const && = delete; }; template<class Lhs, class Rhs> requires closure_has_simple_call_op<Lhs> && closure_has_simple_call_op<Rhs> struct pipe<Lhs, Rhs> : range_adaptor_closure<pipe<Lhs, Rhs>> { [[no_unique_address]] Lhs lhs; [[no_unique_address]] Rhs rhs; constexpr pipe(Lhs _lhs, Rhs _rhs) noexcept(NO_EXCEPT) : lhs(std::move(_lhs)), rhs(std::move(_rhs)) {} template<class Range> requires pipe_invocable<const Lhs &, const Rhs &, Range> inline constexpr auto operator()(Range&& range) const noexcept(NO_EXCEPT) { return rhs(lhs(std::forward<Range>(range))); } static constexpr bool has_simple_call_op = true; }; } // namespace views::adaptor } // namespace uni #line 10 "view/enumerate.hpp" namespace uni { namespace internal { template<class Range> concept range_with_movable_reference = std::ranges::input_range<Range> && std::move_constructible<std::ranges::range_reference_t<Range>> && std::move_constructible<std::ranges::range_rvalue_reference_t<Range>>; } // namespace internal template<std::ranges::view View> requires internal::range_with_movable_reference<View> struct enumerate_view : public std::ranges::view_interface<enumerate_view<View>> { private: View _base = View(); template<bool Const> class iterator; template<bool Const> class sentinel; public: enumerate_view() requires std::default_initializable<View> = default; constexpr explicit enumerate_view(View base) : _base(std::move(base)) {} constexpr auto begin() requires(!internal::simple_view<View>) { return iterator<false>(std::ranges::begin(this->_base), 0); } constexpr auto begin() const requires internal::range_with_movable_reference<const View> { return iterator<true>(std::ranges::begin(this->_base), 0); } constexpr auto end() requires(!internal::simple_view<View>) { if constexpr(std::ranges::common_range<View> && std::ranges::sized_range<View>) { return iterator<false>(std::ranges::end(_base), std::ranges::distance(this->_base)); } else { return sentinel<false>(std::ranges::end(_base)); } } constexpr auto end() const requires internal::range_with_movable_reference<const View> { if constexpr(std::ranges::common_range<const View> && std::ranges::sized_range<const View>) { return iterator<true>(std::ranges::end(_base), std::ranges::distance(_base)); } else { return sentinel<true>(std::ranges::end(_base)); } } constexpr auto size() requires std::ranges::sized_range<View> { return std::ranges::size(_base); } constexpr auto size() const requires std::ranges::sized_range<const View> { return std::ranges::size(_base); } constexpr View base() const & requires std::copy_constructible<View> { return _base; } constexpr View base() && { return std::move(_base); } }; template<class Range> enumerate_view(Range&& ) -> enumerate_view<std::views::all_t<Range>>; template<std::ranges::view View> requires internal::range_with_movable_reference<View> template<bool Const> class enumerate_view<View>::iterator { using Base = internal::maybe_const_t<Const, View>; friend enumerate_view; public: using iterator_category = std::iterator_traits<std::ranges::iterator_t<Base>>::iterator_category; using iterator_concept = internal::most_primitive_iterator_concept<Const, View>; using difference_type = std::ranges::range_difference_t<Base>; using value_type = std::tuple<difference_type, std::ranges::range_value_t<Base>>; private: using rangeeference_type = std::tuple<difference_type, std::ranges::range_reference_t<Base>>; std::ranges::iterator_t<Base> _current = std::ranges::iterator_t<Base>(); difference_type _pos = 0; constexpr explicit iterator(std::ranges::iterator_t<Base> current, const difference_type pos) : _current(std::move(current)), _pos(pos) {} public: iterator() requires std::default_initializable<std::ranges::iterator_t<Base>> = default; constexpr iterator(iterator<!Const> itr) requires Const && std::convertible_to<std::ranges::iterator_t<View>, std::ranges::iterator_t<Base>> : _current(std::move(itr._current)), _pos(itr._pos) {} constexpr const std::ranges::iterator_t<Base>& base() const & noexcept { return this->_current; } constexpr std::ranges::iterator_t<Base> base() && { return std::move(this->_current); } constexpr difference_type index() const noexcept { return this->_pos; } constexpr auto operator*() const { return rangeeference_type(this->_pos, *this->_current); } constexpr iterator& operator++() { ++this->_current; ++this->_pos; return *this; } constexpr void operator++(int) { ++*this; } constexpr iterator operator++(int) requires std::ranges::forward_range<Base> { auto temp = *this; ++*this; return temp; } constexpr iterator& operator--() requires std::ranges::bidirectional_range<Base> { --this->_current; --this->_pos; return *this; } constexpr iterator operator--(int) requires std::ranges::bidirectional_range<Base> { auto temp = *this; --*this; return temp; } constexpr iterator& operator+=(const difference_type diff) requires std::ranges::random_access_range<Base> { this->_current += diff; this->_pos += diff; return *this; } constexpr iterator& operator-=(const difference_type diff) requires std::ranges::random_access_range<Base> { this->_current -= diff; this->_pos -= diff; return *this; } constexpr auto operator[](const difference_type diff) const requires std::ranges::random_access_range<Base> { return rangeeference_type(this->_pos + diff, this->_current[diff]); } friend constexpr bool operator==(const iterator& lhs, const iterator& rhs) noexcept { return lhs._pos == rhs._pos; } friend constexpr std::strong_ordering operator<=>(const iterator& lhs, const iterator& rhs) noexcept { return lhs._pos <=> rhs._pos; } friend constexpr iterator operator+(iterator lhs, const difference_type rhs) requires std::ranges::random_access_range<Base> { return (lhs += rhs); } friend constexpr iterator operator+(const difference_type lhs, const iterator& rhs) requires std::ranges::random_access_range<Base> { return rhs += lhs; } friend constexpr iterator operator-(iterator& lhs, const difference_type rhs) requires std::ranges::random_access_range<Base> { return lhs -= rhs; } friend constexpr difference_type operator-(const iterator& lhs, const iterator& rhs) { return lhs._pos - rhs._pos; } friend constexpr auto iter_move(const iterator& itr) noexcept( noexcept (std::ranges::iter_move(itr._current)) && std::is_nothrow_move_constructible_v<std::ranges::range_rvalue_reference_t<Base>> ) { return std::tuple<difference_type, std::ranges::range_rvalue_reference_t<Base>>( itr._pos, std::ranges::iter_move(itr._current) ); } }; template<std::ranges::view View> requires internal::range_with_movable_reference<View> template<bool Const> class enumerate_view<View>::sentinel { using Base = internal::maybe_const_t<Const, View>; std::ranges::sentinel_t<Base> _end = std::ranges::sentinel_t<Base>(); constexpr explicit sentinel(std::ranges::sentinel_t<Base> end) : _end(std::move(end)) {} friend enumerate_view; public: sentinel() = default; constexpr sentinel(sentinel<!Const> other) requires Const && std::convertible_to<std::ranges::sentinel_t<View>, std::ranges::sentinel_t<Base>> : _end(std::move(other._end)) {} constexpr std::ranges::sentinel_t<Base> base() const { return this->_end; } template<bool Const_> requires std::sentinel_for< std::ranges::sentinel_t<Base>, std::ranges::iterator_t<internal::maybe_const_t<Const_, View>> > friend constexpr bool operator==(const iterator<Const_>& lhs, const sentinel& rhs) { return lhs._current == rhs._end; } template<bool Const_> requires std::sized_sentinel_for< std::ranges::sentinel_t<Base>, std::ranges::iterator_t<internal::maybe_const_t<Const_, View>> > friend constexpr std::ranges::range_difference_t<internal::maybe_const_t<Const_, View>> operator-(const iterator<Const_>& lhs, const sentinel& rhs) { return lhs._current - rhs._end; } template<bool Const_> requires std::sized_sentinel_for< std::ranges::sentinel_t<Base>, std::ranges::iterator_t<internal::maybe_const_t<Const_, View>>> friend constexpr std::ranges::range_difference_t<internal::maybe_const_t<Const_, View>> operator-(const sentinel& lhs, const iterator<Const_>& rhs) { return lhs._end - rhs._current; } }; namespace views { namespace internal { template<class T> concept can_enumerate_view = requires { enumerate_view<std::views::all_t<T>>(std::declval<T>()); }; } // namespace internal struct Enumerate : adaptor::range_adaptor_closure<Enumerate> { template<std::ranges::viewable_range Range> requires internal::can_enumerate_view<Range> constexpr auto operator() [[nodiscard]] (Range&& range) const { return enumerate_view<std::views::all_t<Range>>(std::forward<Range>(range)); } }; inline constexpr Enumerate enumerate; } // namespace views } // namespace uni namespace std::ranges { template<class T> inline constexpr bool enable_borrowed_range<uni::enumerate_view<T>> = enable_borrowed_range<T>; } // namespace std