pocketpy/3rd/numpy/include/xtensor/xiterator.hpp
Anurag Bhat 86b4fc623c
Merge numpy to pocketpy (#303)
* Merge numpy to pocketpy

* Add CI

* Fix CI
2024-09-02 16:22:41 +08:00

1304 lines
36 KiB
C++

/***************************************************************************
* Copyright (c) Johan Mabille, Sylvain Corlay and Wolf Vollprecht *
* Copyright (c) QuantStack *
* *
* Distributed under the terms of the BSD 3-Clause License. *
* *
* The full license is in the file LICENSE, distributed with this software. *
****************************************************************************/
#ifndef XTENSOR_ITERATOR_HPP
#define XTENSOR_ITERATOR_HPP
#include <algorithm>
#include <array>
#include <cstddef>
#include <iterator>
#include <numeric>
#include <vector>
#include <xtl/xcompare.hpp>
#include <xtl/xiterator_base.hpp>
#include <xtl/xmeta_utils.hpp>
#include <xtl/xsequence.hpp>
#include "xexception.hpp"
#include "xlayout.hpp"
#include "xshape.hpp"
#include "xutils.hpp"
namespace xt
{
/***********************
* iterator meta utils *
***********************/
template <class CT>
class xscalar;
template <bool is_const, class CT>
class xscalar_stepper;
namespace detail
{
template <class C>
struct get_stepper_iterator_impl
{
using type = typename C::container_iterator;
};
template <class C>
struct get_stepper_iterator_impl<const C>
{
using type = typename C::const_container_iterator;
};
template <class CT>
struct get_stepper_iterator_impl<xscalar<CT>>
{
using type = typename xscalar<CT>::dummy_iterator;
};
template <class CT>
struct get_stepper_iterator_impl<const xscalar<CT>>
{
using type = typename xscalar<CT>::const_dummy_iterator;
};
}
template <class C>
using get_stepper_iterator = typename detail::get_stepper_iterator_impl<C>::type;
/********************************
* xindex_type_t implementation *
********************************/
namespace detail
{
template <class ST>
struct index_type_impl
{
using type = dynamic_shape<typename ST::value_type>;
};
template <class V, std::size_t L>
struct index_type_impl<std::array<V, L>>
{
using type = std::array<V, L>;
};
template <std::size_t... I>
struct index_type_impl<fixed_shape<I...>>
{
using type = std::array<std::size_t, sizeof...(I)>;
};
}
template <class C>
using xindex_type_t = typename detail::index_type_impl<C>::type;
/************
* xstepper *
************/
template <class C>
class xstepper
{
public:
using storage_type = C;
using subiterator_type = get_stepper_iterator<C>;
using subiterator_traits = std::iterator_traits<subiterator_type>;
using value_type = typename subiterator_traits::value_type;
using reference = typename subiterator_traits::reference;
using pointer = typename subiterator_traits::pointer;
using difference_type = typename subiterator_traits::difference_type;
using size_type = typename storage_type::size_type;
using shape_type = typename storage_type::shape_type;
using simd_value_type = xt_simd::simd_type<value_type>;
template <class requested_type>
using simd_return_type = xt_simd::simd_return_type<value_type, requested_type>;
xstepper() = default;
xstepper(storage_type* c, subiterator_type it, size_type offset) noexcept;
reference operator*() const;
void step(size_type dim, size_type n = 1);
void step_back(size_type dim, size_type n = 1);
void reset(size_type dim);
void reset_back(size_type dim);
void to_begin();
void to_end(layout_type l);
template <class T>
simd_return_type<T> step_simd();
void step_leading();
template <class R>
void store_simd(const R& vec);
private:
storage_type* p_c;
subiterator_type m_it;
size_type m_offset;
};
template <layout_type L>
struct stepper_tools
{
// For performance reasons, increment_stepper and decrement_stepper are
// specialized for the case where n=1, which underlies operator++ and
// operator-- on xiterators.
template <class S, class IT, class ST>
static void increment_stepper(S& stepper, IT& index, const ST& shape);
template <class S, class IT, class ST>
static void decrement_stepper(S& stepper, IT& index, const ST& shape);
template <class S, class IT, class ST>
static void increment_stepper(S& stepper, IT& index, const ST& shape, typename S::size_type n);
template <class S, class IT, class ST>
static void decrement_stepper(S& stepper, IT& index, const ST& shape, typename S::size_type n);
};
/********************
* xindexed_stepper *
********************/
template <class E, bool is_const>
class xindexed_stepper
{
public:
using self_type = xindexed_stepper<E, is_const>;
using xexpression_type = std::conditional_t<is_const, const E, E>;
using value_type = typename xexpression_type::value_type;
using reference = std::
conditional_t<is_const, typename xexpression_type::const_reference, typename xexpression_type::reference>;
using pointer = std::
conditional_t<is_const, typename xexpression_type::const_pointer, typename xexpression_type::pointer>;
using size_type = typename xexpression_type::size_type;
using difference_type = typename xexpression_type::difference_type;
using shape_type = typename xexpression_type::shape_type;
using index_type = xindex_type_t<shape_type>;
xindexed_stepper() = default;
xindexed_stepper(xexpression_type* e, size_type offset, bool end = false) noexcept;
reference operator*() const;
void step(size_type dim, size_type n = 1);
void step_back(size_type dim, size_type n = 1);
void reset(size_type dim);
void reset_back(size_type dim);
void to_begin();
void to_end(layout_type l);
private:
xexpression_type* p_e;
index_type m_index;
size_type m_offset;
};
template <class T>
struct is_indexed_stepper
{
static const bool value = false;
};
template <class T, bool B>
struct is_indexed_stepper<xindexed_stepper<T, B>>
{
static const bool value = true;
};
template <class T, class R = T>
struct enable_indexed_stepper : std::enable_if<is_indexed_stepper<T>::value, R>
{
};
template <class T, class R = T>
using enable_indexed_stepper_t = typename enable_indexed_stepper<T, R>::type;
template <class T, class R = T>
struct disable_indexed_stepper : std::enable_if<!is_indexed_stepper<T>::value, R>
{
};
template <class T, class R = T>
using disable_indexed_stepper_t = typename disable_indexed_stepper<T, R>::type;
/*************
* xiterator *
*************/
namespace detail
{
template <class S>
class shape_storage
{
public:
using shape_type = S;
using param_type = const S&;
shape_storage() = default;
shape_storage(param_type shape);
const S& shape() const;
private:
S m_shape;
};
template <class S>
class shape_storage<S*>
{
public:
using shape_type = S;
using param_type = const S*;
shape_storage(param_type shape = 0);
const S& shape() const;
private:
const S* p_shape;
};
template <layout_type L>
struct LAYOUT_FORBIDEN_FOR_XITERATOR;
}
template <class St, class S, layout_type L>
class xiterator : public xtl::xrandom_access_iterator_base<
xiterator<St, S, L>,
typename St::value_type,
typename St::difference_type,
typename St::pointer,
typename St::reference>,
private detail::shape_storage<S>
{
public:
using self_type = xiterator<St, S, L>;
using stepper_type = St;
using value_type = typename stepper_type::value_type;
using reference = typename stepper_type::reference;
using pointer = typename stepper_type::pointer;
using difference_type = typename stepper_type::difference_type;
using size_type = typename stepper_type::size_type;
using iterator_category = std::random_access_iterator_tag;
using private_base = detail::shape_storage<S>;
using shape_type = typename private_base::shape_type;
using shape_param_type = typename private_base::param_type;
using index_type = xindex_type_t<shape_type>;
xiterator() = default;
// end_index means either reverse_iterator && !end or !reverse_iterator && end
xiterator(St st, shape_param_type shape, bool end_index);
self_type& operator++();
self_type& operator--();
self_type& operator+=(difference_type n);
self_type& operator-=(difference_type n);
difference_type operator-(const self_type& rhs) const;
reference operator*() const;
pointer operator->() const;
bool equal(const xiterator& rhs) const;
bool less_than(const xiterator& rhs) const;
private:
stepper_type m_st;
index_type m_index;
difference_type m_linear_index;
using checking_type = typename detail::LAYOUT_FORBIDEN_FOR_XITERATOR<L>::type;
};
template <class St, class S, layout_type L>
bool operator==(const xiterator<St, S, L>& lhs, const xiterator<St, S, L>& rhs);
template <class St, class S, layout_type L>
bool operator<(const xiterator<St, S, L>& lhs, const xiterator<St, S, L>& rhs);
template <class St, class S, layout_type L>
struct is_contiguous_container<xiterator<St, S, L>> : std::false_type
{
};
/*********************
* xbounded_iterator *
*********************/
template <class It, class BIt>
class xbounded_iterator : public xtl::xrandom_access_iterator_base<
xbounded_iterator<It, BIt>,
typename std::iterator_traits<It>::value_type,
typename std::iterator_traits<It>::difference_type,
typename std::iterator_traits<It>::pointer,
typename std::iterator_traits<It>::reference>
{
public:
using self_type = xbounded_iterator<It, BIt>;
using subiterator_type = It;
using bound_iterator_type = BIt;
using value_type = typename std::iterator_traits<It>::value_type;
using reference = typename std::iterator_traits<It>::reference;
using pointer = typename std::iterator_traits<It>::pointer;
using difference_type = typename std::iterator_traits<It>::difference_type;
using iterator_category = std::random_access_iterator_tag;
xbounded_iterator() = default;
xbounded_iterator(It it, BIt bound_it);
self_type& operator++();
self_type& operator--();
self_type& operator+=(difference_type n);
self_type& operator-=(difference_type n);
difference_type operator-(const self_type& rhs) const;
value_type operator*() const;
bool equal(const self_type& rhs) const;
bool less_than(const self_type& rhs) const;
private:
subiterator_type m_it;
bound_iterator_type m_bound_it;
};
template <class It, class BIt>
bool operator==(const xbounded_iterator<It, BIt>& lhs, const xbounded_iterator<It, BIt>& rhs);
template <class It, class BIt>
bool operator<(const xbounded_iterator<It, BIt>& lhs, const xbounded_iterator<It, BIt>& rhs);
/*****************************
* linear_begin / linear_end *
*****************************/
namespace detail
{
template <class C, class = void_t<>>
struct has_linear_iterator : std::false_type
{
};
template <class C>
struct has_linear_iterator<C, void_t<decltype(std::declval<C>().linear_cbegin())>> : std::true_type
{
};
}
template <class C>
XTENSOR_CONSTEXPR_RETURN auto linear_begin(C& c) noexcept
{
return xtl::mpl::static_if<detail::has_linear_iterator<C>::value>(
[&](auto self)
{
return self(c).linear_begin();
},
/*else*/
[&](auto self)
{
return self(c).begin();
}
);
}
template <class C>
XTENSOR_CONSTEXPR_RETURN auto linear_end(C& c) noexcept
{
return xtl::mpl::static_if<detail::has_linear_iterator<C>::value>(
[&](auto self)
{
return self(c).linear_end();
},
/*else*/
[&](auto self)
{
return self(c).end();
}
);
}
template <class C>
XTENSOR_CONSTEXPR_RETURN auto linear_begin(const C& c) noexcept
{
return xtl::mpl::static_if<detail::has_linear_iterator<C>::value>(
[&](auto self)
{
return self(c).linear_cbegin();
},
/*else*/
[&](auto self)
{
return self(c).cbegin();
}
);
}
template <class C>
XTENSOR_CONSTEXPR_RETURN auto linear_end(const C& c) noexcept
{
return xtl::mpl::static_if<detail::has_linear_iterator<C>::value>(
[&](auto self)
{
return self(c).linear_cend();
},
/*else*/
[&](auto self)
{
return self(c).cend();
}
);
}
/***************************
* xstepper implementation *
***************************/
template <class C>
inline xstepper<C>::xstepper(storage_type* c, subiterator_type it, size_type offset) noexcept
: p_c(c)
, m_it(it)
, m_offset(offset)
{
}
template <class C>
inline auto xstepper<C>::operator*() const -> reference
{
return *m_it;
}
template <class C>
inline void xstepper<C>::step(size_type dim, size_type n)
{
if (dim >= m_offset)
{
using strides_value_type = typename std::decay_t<decltype(p_c->strides())>::value_type;
m_it += difference_type(static_cast<strides_value_type>(n) * p_c->strides()[dim - m_offset]);
}
}
template <class C>
inline void xstepper<C>::step_back(size_type dim, size_type n)
{
if (dim >= m_offset)
{
using strides_value_type = typename std::decay_t<decltype(p_c->strides())>::value_type;
m_it -= difference_type(static_cast<strides_value_type>(n) * p_c->strides()[dim - m_offset]);
}
}
template <class C>
inline void xstepper<C>::reset(size_type dim)
{
if (dim >= m_offset)
{
m_it -= difference_type(p_c->backstrides()[dim - m_offset]);
}
}
template <class C>
inline void xstepper<C>::reset_back(size_type dim)
{
if (dim >= m_offset)
{
m_it += difference_type(p_c->backstrides()[dim - m_offset]);
}
}
template <class C>
inline void xstepper<C>::to_begin()
{
m_it = p_c->data_xbegin();
}
template <class C>
inline void xstepper<C>::to_end(layout_type l)
{
m_it = p_c->data_xend(l, m_offset);
}
namespace detail
{
template <class It>
struct step_simd_invoker
{
template <class R>
static R apply(const It& it)
{
R reg;
return reg.load_unaligned(&(*it));
// return reg;
}
};
template <bool is_const, class T, class S, layout_type L>
struct step_simd_invoker<xiterator<xscalar_stepper<is_const, T>, S, L>>
{
template <class R>
static R apply(const xiterator<xscalar_stepper<is_const, T>, S, L>& it)
{
return R(*it);
}
};
}
template <class C>
template <class T>
inline auto xstepper<C>::step_simd() -> simd_return_type<T>
{
using simd_type = simd_return_type<T>;
simd_type reg = detail::step_simd_invoker<subiterator_type>::template apply<simd_type>(m_it);
m_it += xt_simd::revert_simd_traits<simd_type>::size;
return reg;
}
template <class C>
template <class R>
inline void xstepper<C>::store_simd(const R& vec)
{
vec.store_unaligned(&(*m_it));
m_it += xt_simd::revert_simd_traits<R>::size;
;
}
template <class C>
void xstepper<C>::step_leading()
{
++m_it;
}
template <>
template <class S, class IT, class ST>
void stepper_tools<layout_type::row_major>::increment_stepper(S& stepper, IT& index, const ST& shape)
{
using size_type = typename S::size_type;
const size_type size = index.size();
size_type i = size;
while (i != 0)
{
--i;
if (index[i] != shape[i] - 1)
{
++index[i];
stepper.step(i);
return;
}
else
{
index[i] = 0;
if (i != 0)
{
stepper.reset(i);
}
}
}
if (i == 0)
{
if (size != size_type(0))
{
std::transform(
shape.cbegin(),
shape.cend() - 1,
index.begin(),
[](const auto& v)
{
return v - 1;
}
);
index[size - 1] = shape[size - 1];
}
stepper.to_end(layout_type::row_major);
}
}
template <>
template <class S, class IT, class ST>
void stepper_tools<layout_type::row_major>::increment_stepper(
S& stepper,
IT& index,
const ST& shape,
typename S::size_type n
)
{
using size_type = typename S::size_type;
const size_type size = index.size();
const size_type leading_i = size - 1;
size_type i = size;
while (i != 0 && n != 0)
{
--i;
size_type inc = (i == leading_i) ? n : 1;
if (xtl::cmp_less(index[i] + inc, shape[i]))
{
index[i] += inc;
stepper.step(i, inc);
n -= inc;
if (i != leading_i || index.size() == 1)
{
i = index.size();
}
}
else
{
if (i == leading_i)
{
size_type off = shape[i] - index[i] - 1;
stepper.step(i, off);
n -= off;
}
index[i] = 0;
if (i != 0)
{
stepper.reset(i);
}
}
}
if (i == 0 && n != 0)
{
if (size != size_type(0))
{
std::transform(
shape.cbegin(),
shape.cend() - 1,
index.begin(),
[](const auto& v)
{
return v - 1;
}
);
index[leading_i] = shape[leading_i];
}
stepper.to_end(layout_type::row_major);
}
}
template <>
template <class S, class IT, class ST>
void stepper_tools<layout_type::row_major>::decrement_stepper(S& stepper, IT& index, const ST& shape)
{
using size_type = typename S::size_type;
size_type i = index.size();
while (i != 0)
{
--i;
if (index[i] != 0)
{
--index[i];
stepper.step_back(i);
return;
}
else
{
index[i] = shape[i] - 1;
if (i != 0)
{
stepper.reset_back(i);
}
}
}
if (i == 0)
{
stepper.to_begin();
}
}
template <>
template <class S, class IT, class ST>
void stepper_tools<layout_type::row_major>::decrement_stepper(
S& stepper,
IT& index,
const ST& shape,
typename S::size_type n
)
{
using size_type = typename S::size_type;
size_type i = index.size();
size_type leading_i = index.size() - 1;
while (i != 0 && n != 0)
{
--i;
size_type inc = (i == leading_i) ? n : 1;
if (xtl::cmp_greater_equal(index[i], inc))
{
index[i] -= inc;
stepper.step_back(i, inc);
n -= inc;
if (i != leading_i || index.size() == 1)
{
i = index.size();
}
}
else
{
if (i == leading_i)
{
size_type off = index[i];
stepper.step_back(i, off);
n -= off;
}
index[i] = shape[i] - 1;
if (i != 0)
{
stepper.reset_back(i);
}
}
}
if (i == 0 && n != 0)
{
stepper.to_begin();
}
}
template <>
template <class S, class IT, class ST>
void stepper_tools<layout_type::column_major>::increment_stepper(S& stepper, IT& index, const ST& shape)
{
using size_type = typename S::size_type;
const size_type size = index.size();
size_type i = 0;
while (i != size)
{
if (index[i] != shape[i] - 1)
{
++index[i];
stepper.step(i);
return;
}
else
{
index[i] = 0;
if (i != size - 1)
{
stepper.reset(i);
}
}
++i;
}
if (i == size)
{
if (size != size_type(0))
{
std::transform(
shape.cbegin() + 1,
shape.cend(),
index.begin() + 1,
[](const auto& v)
{
return v - 1;
}
);
index[0] = shape[0];
}
stepper.to_end(layout_type::column_major);
}
}
template <>
template <class S, class IT, class ST>
void stepper_tools<layout_type::column_major>::increment_stepper(
S& stepper,
IT& index,
const ST& shape,
typename S::size_type n
)
{
using size_type = typename S::size_type;
const size_type size = index.size();
const size_type leading_i = 0;
size_type i = 0;
while (i != size && n != 0)
{
size_type inc = (i == leading_i) ? n : 1;
if (index[i] + inc < shape[i])
{
index[i] += inc;
stepper.step(i, inc);
n -= inc;
if (i != leading_i || size == 1)
{
i = 0;
continue;
}
}
else
{
if (i == leading_i)
{
size_type off = shape[i] - index[i] - 1;
stepper.step(i, off);
n -= off;
}
index[i] = 0;
if (i != size - 1)
{
stepper.reset(i);
}
}
++i;
}
if (i == size && n != 0)
{
if (size != size_type(0))
{
std::transform(
shape.cbegin() + 1,
shape.cend(),
index.begin() + 1,
[](const auto& v)
{
return v - 1;
}
);
index[leading_i] = shape[leading_i];
}
stepper.to_end(layout_type::column_major);
}
}
template <>
template <class S, class IT, class ST>
void stepper_tools<layout_type::column_major>::decrement_stepper(S& stepper, IT& index, const ST& shape)
{
using size_type = typename S::size_type;
size_type size = index.size();
size_type i = 0;
while (i != size)
{
if (index[i] != 0)
{
--index[i];
stepper.step_back(i);
return;
}
else
{
index[i] = shape[i] - 1;
if (i != size - 1)
{
stepper.reset_back(i);
}
}
++i;
}
if (i == size)
{
stepper.to_begin();
}
}
template <>
template <class S, class IT, class ST>
void stepper_tools<layout_type::column_major>::decrement_stepper(
S& stepper,
IT& index,
const ST& shape,
typename S::size_type n
)
{
using size_type = typename S::size_type;
size_type size = index.size();
size_type i = 0;
size_type leading_i = 0;
while (i != size && n != 0)
{
size_type inc = (i == leading_i) ? n : 1;
if (index[i] >= inc)
{
index[i] -= inc;
stepper.step_back(i, inc);
n -= inc;
if (i != leading_i || index.size() == 1)
{
i = 0;
continue;
}
}
else
{
if (i == leading_i)
{
size_type off = index[i];
stepper.step_back(i, off);
n -= off;
}
index[i] = shape[i] - 1;
if (i != size - 1)
{
stepper.reset_back(i);
}
}
++i;
}
if (i == size && n != 0)
{
stepper.to_begin();
}
}
/***********************************
* xindexed_stepper implementation *
***********************************/
template <class C, bool is_const>
inline xindexed_stepper<C, is_const>::xindexed_stepper(xexpression_type* e, size_type offset, bool end) noexcept
: p_e(e)
, m_index(xtl::make_sequence<index_type>(e->shape().size(), size_type(0)))
, m_offset(offset)
{
if (end)
{
// Note: the layout here doesn't matter (unused) but using default traversal looks more "correct".
to_end(XTENSOR_DEFAULT_TRAVERSAL);
}
}
template <class C, bool is_const>
inline auto xindexed_stepper<C, is_const>::operator*() const -> reference
{
return p_e->element(m_index.cbegin(), m_index.cend());
}
template <class C, bool is_const>
inline void xindexed_stepper<C, is_const>::step(size_type dim, size_type n)
{
if (dim >= m_offset)
{
m_index[dim - m_offset] += static_cast<typename index_type::value_type>(n);
}
}
template <class C, bool is_const>
inline void xindexed_stepper<C, is_const>::step_back(size_type dim, size_type n)
{
if (dim >= m_offset)
{
m_index[dim - m_offset] -= static_cast<typename index_type::value_type>(n);
}
}
template <class C, bool is_const>
inline void xindexed_stepper<C, is_const>::reset(size_type dim)
{
if (dim >= m_offset)
{
m_index[dim - m_offset] = 0;
}
}
template <class C, bool is_const>
inline void xindexed_stepper<C, is_const>::reset_back(size_type dim)
{
if (dim >= m_offset)
{
m_index[dim - m_offset] = p_e->shape()[dim - m_offset] - 1;
}
}
template <class C, bool is_const>
inline void xindexed_stepper<C, is_const>::to_begin()
{
std::fill(m_index.begin(), m_index.end(), size_type(0));
}
template <class C, bool is_const>
inline void xindexed_stepper<C, is_const>::to_end(layout_type l)
{
const auto& shape = p_e->shape();
std::transform(
shape.cbegin(),
shape.cend(),
m_index.begin(),
[](const auto& v)
{
return v - 1;
}
);
size_type l_dim = (l == layout_type::row_major) ? shape.size() - 1 : 0;
m_index[l_dim] = shape[l_dim];
}
/****************************
* xiterator implementation *
****************************/
namespace detail
{
template <class S>
inline shape_storage<S>::shape_storage(param_type shape)
: m_shape(shape)
{
}
template <class S>
inline const S& shape_storage<S>::shape() const
{
return m_shape;
}
template <class S>
inline shape_storage<S*>::shape_storage(param_type shape)
: p_shape(shape)
{
}
template <class S>
inline const S& shape_storage<S*>::shape() const
{
return *p_shape;
}
template <>
struct LAYOUT_FORBIDEN_FOR_XITERATOR<layout_type::row_major>
{
using type = int;
};
template <>
struct LAYOUT_FORBIDEN_FOR_XITERATOR<layout_type::column_major>
{
using type = int;
};
}
template <class St, class S, layout_type L>
inline xiterator<St, S, L>::xiterator(St st, shape_param_type shape, bool end_index)
: private_base(shape)
, m_st(st)
, m_index(
end_index ? xtl::forward_sequence<index_type, const shape_type&>(this->shape())
: xtl::make_sequence<index_type>(this->shape().size(), size_type(0))
)
, m_linear_index(0)
{
// end_index means either reverse_iterator && !end or !reverse_iterator && end
if (end_index)
{
if (m_index.size() != size_type(0))
{
auto iter_begin = (L == layout_type::row_major) ? m_index.begin() : m_index.begin() + 1;
auto iter_end = (L == layout_type::row_major) ? m_index.end() - 1 : m_index.end();
std::transform(
iter_begin,
iter_end,
iter_begin,
[](const auto& v)
{
return v - 1;
}
);
}
m_linear_index = difference_type(std::accumulate(
this->shape().cbegin(),
this->shape().cend(),
size_type(1),
std::multiplies<size_type>()
));
}
}
template <class St, class S, layout_type L>
inline auto xiterator<St, S, L>::operator++() -> self_type&
{
stepper_tools<L>::increment_stepper(m_st, m_index, this->shape());
++m_linear_index;
return *this;
}
template <class St, class S, layout_type L>
inline auto xiterator<St, S, L>::operator--() -> self_type&
{
stepper_tools<L>::decrement_stepper(m_st, m_index, this->shape());
--m_linear_index;
return *this;
}
template <class St, class S, layout_type L>
inline auto xiterator<St, S, L>::operator+=(difference_type n) -> self_type&
{
if (n >= 0)
{
stepper_tools<L>::increment_stepper(m_st, m_index, this->shape(), static_cast<size_type>(n));
}
else
{
stepper_tools<L>::decrement_stepper(m_st, m_index, this->shape(), static_cast<size_type>(-n));
}
m_linear_index += n;
return *this;
}
template <class St, class S, layout_type L>
inline auto xiterator<St, S, L>::operator-=(difference_type n) -> self_type&
{
if (n >= 0)
{
stepper_tools<L>::decrement_stepper(m_st, m_index, this->shape(), static_cast<size_type>(n));
}
else
{
stepper_tools<L>::increment_stepper(m_st, m_index, this->shape(), static_cast<size_type>(-n));
}
m_linear_index -= n;
return *this;
}
template <class St, class S, layout_type L>
inline auto xiterator<St, S, L>::operator-(const self_type& rhs) const -> difference_type
{
return m_linear_index - rhs.m_linear_index;
}
template <class St, class S, layout_type L>
inline auto xiterator<St, S, L>::operator*() const -> reference
{
return *m_st;
}
template <class St, class S, layout_type L>
inline auto xiterator<St, S, L>::operator->() const -> pointer
{
return &(*m_st);
}
template <class St, class S, layout_type L>
inline bool xiterator<St, S, L>::equal(const xiterator& rhs) const
{
XTENSOR_ASSERT(this->shape() == rhs.shape());
return m_linear_index == rhs.m_linear_index;
}
template <class St, class S, layout_type L>
inline bool xiterator<St, S, L>::less_than(const xiterator& rhs) const
{
XTENSOR_ASSERT(this->shape() == rhs.shape());
return m_linear_index < rhs.m_linear_index;
}
template <class St, class S, layout_type L>
inline bool operator==(const xiterator<St, S, L>& lhs, const xiterator<St, S, L>& rhs)
{
return lhs.equal(rhs);
}
template <class St, class S, layout_type L>
bool operator<(const xiterator<St, S, L>& lhs, const xiterator<St, S, L>& rhs)
{
return lhs.less_than(rhs);
}
/************************************
* xbounded_iterator implementation *
************************************/
template <class It, class BIt>
xbounded_iterator<It, BIt>::xbounded_iterator(It it, BIt bound_it)
: m_it(it)
, m_bound_it(bound_it)
{
}
template <class It, class BIt>
inline auto xbounded_iterator<It, BIt>::operator++() -> self_type&
{
++m_it;
++m_bound_it;
return *this;
}
template <class It, class BIt>
inline auto xbounded_iterator<It, BIt>::operator--() -> self_type&
{
--m_it;
--m_bound_it;
return *this;
}
template <class It, class BIt>
inline auto xbounded_iterator<It, BIt>::operator+=(difference_type n) -> self_type&
{
m_it += n;
m_bound_it += n;
return *this;
}
template <class It, class BIt>
inline auto xbounded_iterator<It, BIt>::operator-=(difference_type n) -> self_type&
{
m_it -= n;
m_bound_it -= n;
return *this;
}
template <class It, class BIt>
inline auto xbounded_iterator<It, BIt>::operator-(const self_type& rhs) const -> difference_type
{
return m_it - rhs.m_it;
}
template <class It, class BIt>
inline auto xbounded_iterator<It, BIt>::operator*() const -> value_type
{
using type = decltype(*m_bound_it);
return (static_cast<type>(*m_it) < *m_bound_it) ? *m_it : static_cast<value_type>((*m_bound_it) - 1);
}
template <class It, class BIt>
inline bool xbounded_iterator<It, BIt>::equal(const self_type& rhs) const
{
return m_it == rhs.m_it && m_bound_it == rhs.m_bound_it;
}
template <class It, class BIt>
inline bool xbounded_iterator<It, BIt>::less_than(const self_type& rhs) const
{
return m_it < rhs.m_it;
}
template <class It, class BIt>
inline bool operator==(const xbounded_iterator<It, BIt>& lhs, const xbounded_iterator<It, BIt>& rhs)
{
return lhs.equal(rhs);
}
template <class It, class BIt>
inline bool operator<(const xbounded_iterator<It, BIt>& lhs, const xbounded_iterator<It, BIt>& rhs)
{
return lhs.less_than(rhs);
}
}
#endif