Zip
(src/utils/py-like/zip.hpp)

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Last update: 2022-04-06 16:00:36+09:00
Include: #include "src/utils/py-like/zip.hpp"
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80438

Depends on

Required by

Enumerate (src/utils/py-like/enumerate.hpp)

Verified with

test/library-checker/number_of_substrings.test.cpp

Code

#pragma once

/**
 * @file zip.hpp
 * @brief Zip
 */

#include <cstddef>
#include <tuple>
#include <vector>

#include "../iterator/category.hpp"
#include "../iterator/reverse.hpp"
#include "lib/cxx17"

namespace workspace {

template <class _Tuple> class zipped : protected _Tuple {
 public:
  zipped(const _Tuple &__x) : _Tuple(__x) {}

  template <std::size_t _Nm> constexpr decltype(auto) get() const &noexcept {
    return *std::get<_Nm>(*this);
  }

  template <std::size_t _Nm> constexpr decltype(auto) get() &&noexcept {
    auto __tmp = *std::get<_Nm>(*this);
    return __tmp;
  }
};

template <class... _Containers> class zip {
  std::tuple<_Containers...> __c;

  template <std::size_t _Nm = 0>
  constexpr decltype(auto) begin_cat() const noexcept {
    if _CXX17_CONSTEXPR (_Nm != sizeof...(_Containers)) {
      return std::tuple_cat(std::tuple(std::begin(std::get<_Nm>(__c))),
                            begin_cat<_Nm + 1>());
    } else
      return std::tuple<>();
  }

  template <std::size_t _Nm = 0>
  constexpr decltype(auto) end_cat() const noexcept {
    if _CXX17_CONSTEXPR (_Nm != sizeof...(_Containers)) {
      return std::tuple_cat(std::tuple(std::end(std::get<_Nm>(__c))),
                            end_cat<_Nm + 1>());
    } else
      return std::tuple<>();
  }

  using _Iterator_tuple =
      std::tuple<decltype(std::begin(std::declval<_Containers>()))...>;

 public:
  using size_type = std::size_t;

  class iterator : public zipped<_Iterator_tuple> {
    using _Base = zipped<_Iterator_tuple>;

   public:
    using difference_type = std::ptrdiff_t;
    using value_type = _Base;
    using pointer = void;
    using reference = value_type &;
    using iterator_category =
        typename common_iterator_category<_Iterator_tuple>::type;

   protected:
    template <std::size_t _Nm = 0>
    constexpr bool equal(const iterator &__x) const noexcept {
      if _CXX17_CONSTEXPR (_Nm != sizeof...(_Containers)) {
        return std::get<_Nm>(*this) == std::get<_Nm>(__x) ||
               equal<_Nm + 1>(__x);
      } else
        return false;
    }

    template <std::size_t _Nm = 0> constexpr void increment() noexcept {
      if _CXX17_CONSTEXPR (_Nm != sizeof...(_Containers))
        ++std::get<_Nm>(*this), increment<_Nm + 1>();
    }

    template <std::size_t _Nm = 0> constexpr void decrement() noexcept {
      if _CXX17_CONSTEXPR (_Nm != sizeof...(_Containers))
        --std::get<_Nm>(*this), decrement<_Nm + 1>();
    }

    template <std::size_t _Nm = 0>
    constexpr void advance(difference_type __d) noexcept {
      if _CXX17_CONSTEXPR (_Nm != sizeof...(_Containers))
        std::get<_Nm>(*this) += __d, advance<_Nm + 1>(__d);
    }

   public:
    iterator(const _Iterator_tuple &__x) : _Base(__x) {}

    constexpr bool operator==(const iterator &__x) const noexcept {
      return equal(__x);
    }
    constexpr bool operator!=(const iterator &__x) const noexcept {
      return !equal(__x);
    }

    constexpr iterator &operator++() noexcept {
      increment();
      return *this;
    }
    constexpr iterator operator++(int) noexcept {
      auto __tmp = *this;
      increment();
      return __tmp;
    }

    constexpr iterator &operator--() noexcept {
      decrement();
      return *this;
    }
    constexpr iterator operator--(int) noexcept {
      auto __tmp = *this;
      decrement();
      return __tmp;
    }

    constexpr bool operator<(const iterator &__x) const noexcept {
      return std::get<0>(*this) < std::get<0>(__x);
    }
    constexpr bool operator<=(const iterator &__x) const noexcept {
      return std::get<0>(*this) <= std::get<0>(__x);
    }
    constexpr bool operator>(const iterator &__x) const noexcept {
      return !operator<=(__x);
    }
    constexpr bool operator>=(const iterator &__x) const noexcept {
      return !operator>(__x);
    }

    constexpr iterator &operator+=(difference_type __d) noexcept {
      advance(__d);
      return *this;
    }
    constexpr iterator &operator-=(difference_type __d) noexcept {
      advance(-__d);
      return *this;
    }
    constexpr iterator operator+(difference_type __d) const noexcept {
      return iterator{*this} += __d;
    }
    constexpr iterator operator-(difference_type __d) const noexcept {
      return iterator{*this} -= __d;
    }

    constexpr difference_type operator-(const iterator &__x) const noexcept {
      return std::get<0>(*this) - std::get<0>(__x);
    }

    constexpr reference operator*() noexcept { return {*this}; }
  };

  using const_iterator = iterator;

  template <class... _Args>
  constexpr zip(_Args &&...__args) noexcept
      : __c(std::forward<_Args>(__args)...) {}

  template <class... _Args>
  constexpr zip(std::initializer_list<_Args>... __args) noexcept
      : __c(std::forward<_Args>(__args)...) {}

  constexpr iterator begin() const noexcept { return {begin_cat()}; }

  constexpr iterator end() const noexcept { return {end_cat()}; }

  constexpr reverse_iterator<iterator> rbegin() const noexcept {
    return reverse_iterator<iterator>{end()};
  }

  constexpr reverse_iterator<iterator> rend() const noexcept {
    return reverse_iterator<iterator>{begin()};
  }

#if __cplusplus >= 201703L
  constexpr size_type size() const noexcept {
    size_type __n = -1;
    std::apply(
        [&__n](auto &&__x) {
          if (__n < __x.size()) __n = __x.size();
        },
        __c);
    return __n;
  }
#endif
};

#if __cpp_deduction_guides >= 201606L

template <class... _Args> zip(_Args &&...) -> zip<_Args...>;

// For gcc version < 10
// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80438
template <class _Tp, class... _Args>
zip(_Tp &&, _Args &&...) -> zip<_Tp, _Args...>;

template <class... _Args>
zip(std::initializer_list<_Args>...) -> zip<std::initializer_list<_Args>...>;

#endif

}  // namespace workspace

namespace std {

template <size_t _Nm, class _Tuple>
struct tuple_element<_Nm, workspace::zipped<_Tuple>> {
  using type = remove_reference_t<
      typename iterator_traits<tuple_element_t<_Nm, _Tuple>>::reference>;
};

template <class _Tuple>
struct tuple_size<workspace::zipped<_Tuple>> : tuple_size<_Tuple> {};

}  // namespace std

#line 2 "src/utils/py-like/zip.hpp"

/**
 * @file zip.hpp
 * @brief Zip
 */

#include <cstddef>
#include <tuple>
#include <vector>

#line 2 "src/utils/iterator/category.hpp"

/*
 * @file category.hpp
 * @brief Iterator Category
 */

#line 10 "src/utils/iterator/category.hpp"

namespace workspace {

/*
 * @tparam Tuple Tuple of iterator types
 */
template <class Tuple, size_t N = std::tuple_size<Tuple>::value - 1>
struct common_iterator_category {
  using type = typename std::common_type<
      typename common_iterator_category<Tuple, N - 1>::type,
      typename std::iterator_traits<typename std::tuple_element<
          N, Tuple>::type>::iterator_category>::type;
};

template <class Tuple> struct common_iterator_category<Tuple, 0> {
  using type = typename std::iterator_traits<
      typename std::tuple_element<0, Tuple>::type>::iterator_category;
};

}  // namespace workspace
#line 2 "src/utils/iterator/reverse.hpp"

/*
 * @file reverse_iterator.hpp
 * @brief Reverse Iterator
 */

#if __cplusplus >= 201703L

#include <iterator>
#include <optional>

namespace workspace {

/*
 * @class reverse_iterator
 * @brief Wrapper class for `std::reverse_iterator`.
 * @see http://gcc.gnu.org/PR51823
 */
template <class Iterator>
class reverse_iterator : public std::reverse_iterator<Iterator> {
  using base_std = std::reverse_iterator<Iterator>;
  std::optional<typename base_std::value_type> deref;

 public:
  using base_std::reverse_iterator;

  constexpr typename base_std::reference operator*() noexcept {
    if (!deref) {
      Iterator tmp = base_std::current;
      deref = *--tmp;
    }
    return deref.value();
  }

  constexpr reverse_iterator &operator++() noexcept {
    base_std::operator++();
    deref.reset();
    return *this;
  }
  constexpr reverse_iterator &operator--() noexcept {
    base_std::operator++();
    deref.reset();
    return *this;
  }
  constexpr reverse_iterator operator++(int) noexcept {
    base_std::operator++();
    deref.reset();
    return *this;
  }
  constexpr reverse_iterator operator--(int) noexcept {
    base_std::operator++();
    deref.reset();
    return *this;
  }
};

}  // namespace workspace

#endif
#line 2 "lib/cxx17"

#line 2 "lib/cxx14"

#ifndef _CXX14_CONSTEXPR
#if __cplusplus >= 201402L
#define _CXX14_CONSTEXPR constexpr
#else
#define _CXX14_CONSTEXPR
#endif
#endif
#line 4 "lib/cxx17"

#ifndef _CXX17_CONSTEXPR
#if __cplusplus >= 201703L
#define _CXX17_CONSTEXPR constexpr
#else
#define _CXX17_CONSTEXPR
#endif
#endif

#ifndef _CXX17_STATIC_ASSERT
#if __cplusplus >= 201703L
#define _CXX17_STATIC_ASSERT static_assert
#else
#define _CXX17_STATIC_ASSERT assert
#endif
#endif

#include <iterator>

#if __cplusplus < 201703L

namespace std {

/**
 *  @brief  Return the size of a container.
 *  @param  __cont  Container.
 */
template <typename _Container>
constexpr auto size(const _Container& __cont) noexcept(noexcept(__cont.size()))
    -> decltype(__cont.size()) {
  return __cont.size();
}

/**
 *  @brief  Return the size of an array.
 */
template <typename _Tp, size_t _Nm>
constexpr size_t size(const _Tp (&)[_Nm]) noexcept {
  return _Nm;
}

/**
 *  @brief  Return whether a container is empty.
 *  @param  __cont  Container.
 */
template <typename _Container>
[[nodiscard]] constexpr auto empty(const _Container& __cont) noexcept(
    noexcept(__cont.empty())) -> decltype(__cont.empty()) {
  return __cont.empty();
}

/**
 *  @brief  Return whether an array is empty (always false).
 */
template <typename _Tp, size_t _Nm>
[[nodiscard]] constexpr bool empty(const _Tp (&)[_Nm]) noexcept {
  return false;
}

/**
 *  @brief  Return whether an initializer_list is empty.
 *  @param  __il  Initializer list.
 */
template <typename _Tp>
[[nodiscard]] constexpr bool empty(initializer_list<_Tp> __il) noexcept {
  return __il.size() == 0;
}

struct monostate {};

}  // namespace std

#else

#include <variant>

#endif
#line 15 "src/utils/py-like/zip.hpp"

namespace workspace {

template <class _Tuple> class zipped : protected _Tuple {
 public:
  zipped(const _Tuple &__x) : _Tuple(__x) {}

  template <std::size_t _Nm> constexpr decltype(auto) get() const &noexcept {
    return *std::get<_Nm>(*this);
  }

  template <std::size_t _Nm> constexpr decltype(auto) get() &&noexcept {
    auto __tmp = *std::get<_Nm>(*this);
    return __tmp;
  }
};

template <class... _Containers> class zip {
  std::tuple<_Containers...> __c;

  template <std::size_t _Nm = 0>
  constexpr decltype(auto) begin_cat() const noexcept {
    if _CXX17_CONSTEXPR (_Nm != sizeof...(_Containers)) {
      return std::tuple_cat(std::tuple(std::begin(std::get<_Nm>(__c))),
                            begin_cat<_Nm + 1>());
    } else
      return std::tuple<>();
  }

  template <std::size_t _Nm = 0>
  constexpr decltype(auto) end_cat() const noexcept {
    if _CXX17_CONSTEXPR (_Nm != sizeof...(_Containers)) {
      return std::tuple_cat(std::tuple(std::end(std::get<_Nm>(__c))),
                            end_cat<_Nm + 1>());
    } else
      return std::tuple<>();
  }

  using _Iterator_tuple =
      std::tuple<decltype(std::begin(std::declval<_Containers>()))...>;

 public:
  using size_type = std::size_t;

  class iterator : public zipped<_Iterator_tuple> {
    using _Base = zipped<_Iterator_tuple>;

   public:
    using difference_type = std::ptrdiff_t;
    using value_type = _Base;
    using pointer = void;
    using reference = value_type &;
    using iterator_category =
        typename common_iterator_category<_Iterator_tuple>::type;

   protected:
    template <std::size_t _Nm = 0>
    constexpr bool equal(const iterator &__x) const noexcept {
      if _CXX17_CONSTEXPR (_Nm != sizeof...(_Containers)) {
        return std::get<_Nm>(*this) == std::get<_Nm>(__x) ||
               equal<_Nm + 1>(__x);
      } else
        return false;
    }

    template <std::size_t _Nm = 0> constexpr void increment() noexcept {
      if _CXX17_CONSTEXPR (_Nm != sizeof...(_Containers))
        ++std::get<_Nm>(*this), increment<_Nm + 1>();
    }

    template <std::size_t _Nm = 0> constexpr void decrement() noexcept {
      if _CXX17_CONSTEXPR (_Nm != sizeof...(_Containers))
        --std::get<_Nm>(*this), decrement<_Nm + 1>();
    }

    template <std::size_t _Nm = 0>
    constexpr void advance(difference_type __d) noexcept {
      if _CXX17_CONSTEXPR (_Nm != sizeof...(_Containers))
        std::get<_Nm>(*this) += __d, advance<_Nm + 1>(__d);
    }

   public:
    iterator(const _Iterator_tuple &__x) : _Base(__x) {}

    constexpr bool operator==(const iterator &__x) const noexcept {
      return equal(__x);
    }
    constexpr bool operator!=(const iterator &__x) const noexcept {
      return !equal(__x);
    }

    constexpr iterator &operator++() noexcept {
      increment();
      return *this;
    }
    constexpr iterator operator++(int) noexcept {
      auto __tmp = *this;
      increment();
      return __tmp;
    }

    constexpr iterator &operator--() noexcept {
      decrement();
      return *this;
    }
    constexpr iterator operator--(int) noexcept {
      auto __tmp = *this;
      decrement();
      return __tmp;
    }

    constexpr bool operator<(const iterator &__x) const noexcept {
      return std::get<0>(*this) < std::get<0>(__x);
    }
    constexpr bool operator<=(const iterator &__x) const noexcept {
      return std::get<0>(*this) <= std::get<0>(__x);
    }
    constexpr bool operator>(const iterator &__x) const noexcept {
      return !operator<=(__x);
    }
    constexpr bool operator>=(const iterator &__x) const noexcept {
      return !operator>(__x);
    }

    constexpr iterator &operator+=(difference_type __d) noexcept {
      advance(__d);
      return *this;
    }
    constexpr iterator &operator-=(difference_type __d) noexcept {
      advance(-__d);
      return *this;
    }
    constexpr iterator operator+(difference_type __d) const noexcept {
      return iterator{*this} += __d;
    }
    constexpr iterator operator-(difference_type __d) const noexcept {
      return iterator{*this} -= __d;
    }

    constexpr difference_type operator-(const iterator &__x) const noexcept {
      return std::get<0>(*this) - std::get<0>(__x);
    }

    constexpr reference operator*() noexcept { return {*this}; }
  };

  using const_iterator = iterator;

  template <class... _Args>
  constexpr zip(_Args &&...__args) noexcept
      : __c(std::forward<_Args>(__args)...) {}

  template <class... _Args>
  constexpr zip(std::initializer_list<_Args>... __args) noexcept
      : __c(std::forward<_Args>(__args)...) {}

  constexpr iterator begin() const noexcept { return {begin_cat()}; }

  constexpr iterator end() const noexcept { return {end_cat()}; }

  constexpr reverse_iterator<iterator> rbegin() const noexcept {
    return reverse_iterator<iterator>{end()};
  }

  constexpr reverse_iterator<iterator> rend() const noexcept {
    return reverse_iterator<iterator>{begin()};
  }

#if __cplusplus >= 201703L
  constexpr size_type size() const noexcept {
    size_type __n = -1;
    std::apply(
        [&__n](auto &&__x) {
          if (__n < __x.size()) __n = __x.size();
        },
        __c);
    return __n;
  }
#endif
};

#if __cpp_deduction_guides >= 201606L

template <class... _Args> zip(_Args &&...) -> zip<_Args...>;

// For gcc version < 10
// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80438
template <class _Tp, class... _Args>
zip(_Tp &&, _Args &&...) -> zip<_Tp, _Args...>;

template <class... _Args>
zip(std::initializer_list<_Args>...) -> zip<std::initializer_list<_Args>...>;

#endif

}  // namespace workspace

namespace std {

template <size_t _Nm, class _Tuple>
struct tuple_element<_Nm, workspace::zipped<_Tuple>> {
  using type = remove_reference_t<
      typename iterator_traits<tuple_element_t<_Nm, _Tuple>>::reference>;
};

template <class _Tuple>
struct tuple_size<workspace::zipped<_Tuple>> : tuple_size<_Tuple> {};

}  // namespace std

Zip (src/utils/py-like/zip.hpp)

Depends on

Required by

Verified with

Code

Zip
(src/utils/py-like/zip.hpp)