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llvm-project/libcxx/test/support/test_iterators.h

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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef SUPPORT_TEST_ITERATORS_H
#define SUPPORT_TEST_ITERATORS_H
#include <cassert>
#include <iterator>
#include <stdexcept>
#include <utility>
#include "test_macros.h"
template <class It>
class output_iterator
{
It it_;
template <class U> friend class output_iterator;
public:
typedef std::output_iterator_tag iterator_category;
typedef void value_type;
typedef typename std::iterator_traits<It>::difference_type difference_type;
typedef It pointer;
typedef typename std::iterator_traits<It>::reference reference;
TEST_CONSTEXPR_CXX14 It base() const {return it_;}
TEST_CONSTEXPR_CXX14 output_iterator() {}
explicit TEST_CONSTEXPR_CXX14 output_iterator(It it) : it_(it) {}
template <class U>
TEST_CONSTEXPR_CXX14 output_iterator(const output_iterator<U>& u) :it_(u.it_) {}
TEST_CONSTEXPR_CXX14 reference operator*() const {return *it_;}
TEST_CONSTEXPR_CXX14 output_iterator& operator++() {++it_; return *this;}
TEST_CONSTEXPR_CXX14 output_iterator operator++(int)
{output_iterator tmp(*this); ++(*this); return tmp;}
friend TEST_CONSTEXPR It base(const output_iterator& i) { return i.it_; }
template <class T>
void operator,(T const &) = delete;
};
// This is the Cpp17InputIterator requirement as described in Table 87 ([input.iterators]),
// formerly known as InputIterator prior to C++20.
template <class It, class ItTraits = It>
class cpp17_input_iterator
{
typedef std::iterator_traits<ItTraits> Traits;
It it_;
template <class U, class T> friend class cpp17_input_iterator;
public:
typedef std::input_iterator_tag iterator_category;
typedef typename Traits::value_type value_type;
typedef typename Traits::difference_type difference_type;
typedef It pointer;
typedef typename Traits::reference reference;
TEST_CONSTEXPR_CXX14 It base() const {return it_;}
TEST_CONSTEXPR_CXX14 cpp17_input_iterator() : it_() {}
explicit TEST_CONSTEXPR_CXX14 cpp17_input_iterator(It it) : it_(it) {}
template <class U, class T>
TEST_CONSTEXPR_CXX14 cpp17_input_iterator(const cpp17_input_iterator<U, T>& u) :it_(u.it_) {}
TEST_CONSTEXPR_CXX14 reference operator*() const {return *it_;}
TEST_CONSTEXPR_CXX14 pointer operator->() const {return it_;}
TEST_CONSTEXPR_CXX14 cpp17_input_iterator& operator++() {++it_; return *this;}
TEST_CONSTEXPR_CXX14 cpp17_input_iterator operator++(int)
{cpp17_input_iterator tmp(*this); ++(*this); return tmp;}
friend TEST_CONSTEXPR_CXX14 bool operator==(const cpp17_input_iterator& x, const cpp17_input_iterator& y)
{return x.it_ == y.it_;}
friend TEST_CONSTEXPR_CXX14 bool operator!=(const cpp17_input_iterator& x, const cpp17_input_iterator& y)
{return !(x == y);}
friend TEST_CONSTEXPR It base(const cpp17_input_iterator& i) { return i.it_; }
template <class T>
void operator,(T const &) = delete;
};
template <class T, class TV, class U, class UV>
bool operator==(const cpp17_input_iterator<T, TV>& x, const cpp17_input_iterator<U, UV>& y)
{
return x.base() == y.base();
}
template <class T, class TV, class U, class UV>
bool operator!=(const cpp17_input_iterator<T, TV>& x, const cpp17_input_iterator<U, UV>& y)
{
return !(x == y);
}
template <class It>
class forward_iterator
{
It it_;
template <class U> friend class forward_iterator;
public:
typedef std::forward_iterator_tag iterator_category;
typedef typename std::iterator_traits<It>::value_type value_type;
typedef typename std::iterator_traits<It>::difference_type difference_type;
typedef It pointer;
typedef typename std::iterator_traits<It>::reference reference;
TEST_CONSTEXPR_CXX14 It base() const {return it_;}
TEST_CONSTEXPR_CXX14 forward_iterator() : it_() {}
explicit TEST_CONSTEXPR_CXX14 forward_iterator(It it) : it_(it) {}
template <class U>
TEST_CONSTEXPR_CXX14 forward_iterator(const forward_iterator<U>& u) :it_(u.it_) {}
TEST_CONSTEXPR_CXX14 reference operator*() const {return *it_;}
TEST_CONSTEXPR_CXX14 pointer operator->() const {return it_;}
TEST_CONSTEXPR_CXX14 forward_iterator& operator++() {++it_; return *this;}
TEST_CONSTEXPR_CXX14 forward_iterator operator++(int)
{forward_iterator tmp(*this); ++(*this); return tmp;}
friend TEST_CONSTEXPR_CXX14 bool operator==(const forward_iterator& x, const forward_iterator& y)
{return x.it_ == y.it_;}
friend TEST_CONSTEXPR_CXX14 bool operator!=(const forward_iterator& x, const forward_iterator& y)
{return !(x == y);}
friend TEST_CONSTEXPR It base(const forward_iterator& i) { return i.it_; }
template <class T>
void operator,(T const &) = delete;
};
template <class T, class U>
TEST_CONSTEXPR_CXX14
bool operator==(const forward_iterator<T>& x, const forward_iterator<U>& y)
{
return x.base() == y.base();
}
template <class T, class U>
TEST_CONSTEXPR_CXX14
bool operator!=(const forward_iterator<T>& x, const forward_iterator<U>& y)
{
return !(x == y);
}
template <class It>
class non_default_constructible_iterator
{
It it_;
template <class U> friend class non_default_constructible_iterator;
public:
typedef std::input_iterator_tag iterator_category;
typedef typename std::iterator_traits<It>::value_type value_type;
typedef typename std::iterator_traits<It>::difference_type difference_type;
typedef It pointer;
typedef typename std::iterator_traits<It>::reference reference;
TEST_CONSTEXPR_CXX14 It base() const {return it_;}
non_default_constructible_iterator() = delete;
explicit TEST_CONSTEXPR_CXX14 non_default_constructible_iterator(It it) : it_(it) {}
template <class U>
TEST_CONSTEXPR_CXX14 non_default_constructible_iterator(const non_default_constructible_iterator<U>& u) :it_(u.it_) {}
TEST_CONSTEXPR_CXX14 reference operator*() const {return *it_;}
TEST_CONSTEXPR_CXX14 pointer operator->() const {return it_;}
TEST_CONSTEXPR_CXX14 non_default_constructible_iterator& operator++() {++it_; return *this;}
TEST_CONSTEXPR_CXX14 non_default_constructible_iterator operator++(int)
{non_default_constructible_iterator tmp(*this); ++(*this); return tmp;}
friend TEST_CONSTEXPR_CXX14 bool operator==(const non_default_constructible_iterator& x, const non_default_constructible_iterator& y)
{return x.it_ == y.it_;}
friend TEST_CONSTEXPR_CXX14 bool operator!=(const non_default_constructible_iterator& x, const non_default_constructible_iterator& y)
{return !(x == y);}
template <class T>
void operator,(T const &) = delete;
};
template <class T, class U>
TEST_CONSTEXPR_CXX14
bool operator==(const non_default_constructible_iterator<T>& x, const non_default_constructible_iterator<U>& y)
{
return x.base() == y.base();
}
template <class T, class U>
TEST_CONSTEXPR_CXX14
bool operator!=(const non_default_constructible_iterator<T>& x, const non_default_constructible_iterator<U>& y)
{
return !(x == y);
}
template <class It>
class bidirectional_iterator
{
It it_;
template <class U> friend class bidirectional_iterator;
public:
typedef std::bidirectional_iterator_tag iterator_category;
typedef typename std::iterator_traits<It>::value_type value_type;
typedef typename std::iterator_traits<It>::difference_type difference_type;
typedef It pointer;
typedef typename std::iterator_traits<It>::reference reference;
TEST_CONSTEXPR_CXX14 It base() const {return it_;}
TEST_CONSTEXPR_CXX14 bidirectional_iterator() : it_() {}
explicit TEST_CONSTEXPR_CXX14 bidirectional_iterator(It it) : it_(it) {}
template <class U>
TEST_CONSTEXPR_CXX14 bidirectional_iterator(const bidirectional_iterator<U>& u) :it_(u.it_) {}
TEST_CONSTEXPR_CXX14 reference operator*() const {return *it_;}
TEST_CONSTEXPR_CXX14 pointer operator->() const {return it_;}
TEST_CONSTEXPR_CXX14 bidirectional_iterator& operator++() {++it_; return *this;}
TEST_CONSTEXPR_CXX14 bidirectional_iterator operator++(int)
{bidirectional_iterator tmp(*this); ++(*this); return tmp;}
TEST_CONSTEXPR_CXX14 bidirectional_iterator& operator--() {--it_; return *this;}
TEST_CONSTEXPR_CXX14 bidirectional_iterator operator--(int)
{bidirectional_iterator tmp(*this); --(*this); return tmp;}
friend TEST_CONSTEXPR It base(const bidirectional_iterator& i) { return i.it_; }
template <class T>
void operator,(T const &) = delete;
};
template <class T, class U>
TEST_CONSTEXPR_CXX14
bool operator==(const bidirectional_iterator<T>& x, const bidirectional_iterator<U>& y)
{
return x.base() == y.base();
}
template <class T, class U>
TEST_CONSTEXPR_CXX14
bool operator!=(const bidirectional_iterator<T>& x, const bidirectional_iterator<U>& y)
{
return !(x == y);
}
template <class It>
class random_access_iterator
{
It it_;
template <class U> friend class random_access_iterator;
public:
typedef std::random_access_iterator_tag iterator_category;
typedef typename std::iterator_traits<It>::value_type value_type;
typedef typename std::iterator_traits<It>::difference_type difference_type;
typedef It pointer;
typedef typename std::iterator_traits<It>::reference reference;
TEST_CONSTEXPR_CXX14 It base() const {return it_;}
TEST_CONSTEXPR_CXX14 random_access_iterator() : it_() {}
explicit TEST_CONSTEXPR_CXX14 random_access_iterator(It it) : it_(it) {}
template <class U>
TEST_CONSTEXPR_CXX14 random_access_iterator(const random_access_iterator<U>& u) :it_(u.it_) {}
TEST_CONSTEXPR_CXX14 reference operator*() const {return *it_;}
TEST_CONSTEXPR_CXX14 pointer operator->() const {return it_;}
TEST_CONSTEXPR_CXX14 random_access_iterator& operator++() {++it_; return *this;}
TEST_CONSTEXPR_CXX14 random_access_iterator operator++(int)
{random_access_iterator tmp(*this); ++(*this); return tmp;}
TEST_CONSTEXPR_CXX14 random_access_iterator& operator--() {--it_; return *this;}
TEST_CONSTEXPR_CXX14 random_access_iterator operator--(int)
{random_access_iterator tmp(*this); --(*this); return tmp;}
TEST_CONSTEXPR_CXX14 random_access_iterator& operator+=(difference_type n) {it_ += n; return *this;}
TEST_CONSTEXPR_CXX14 random_access_iterator operator+(difference_type n) const
{random_access_iterator tmp(*this); tmp += n; return tmp;}
friend TEST_CONSTEXPR_CXX14 random_access_iterator operator+(difference_type n, random_access_iterator x)
{x += n; return x;}
TEST_CONSTEXPR_CXX14 random_access_iterator& operator-=(difference_type n) {return *this += -n;}
TEST_CONSTEXPR_CXX14 random_access_iterator operator-(difference_type n) const
{random_access_iterator tmp(*this); tmp -= n; return tmp;}
TEST_CONSTEXPR_CXX14 reference operator[](difference_type n) const {return it_[n];}
friend TEST_CONSTEXPR It base(const random_access_iterator& i) { return i.it_; }
template <class T>
void operator,(T const &) = delete;
};
template <class T, class U>
TEST_CONSTEXPR_CXX14
bool operator==(const random_access_iterator<T>& x, const random_access_iterator<U>& y)
{
return x.base() == y.base();
}
template <class T, class U>
TEST_CONSTEXPR_CXX14
bool operator!=(const random_access_iterator<T>& x, const random_access_iterator<U>& y)
{
return !(x == y);
}
template <class T, class U>
TEST_CONSTEXPR_CXX14
bool operator<(const random_access_iterator<T>& x, const random_access_iterator<U>& y)
{
return x.base() < y.base();
}
template <class T, class U>
TEST_CONSTEXPR_CXX14
bool operator<=(const random_access_iterator<T>& x, const random_access_iterator<U>& y)
{
return !(y < x);
}
template <class T, class U>
TEST_CONSTEXPR_CXX14
bool operator>(const random_access_iterator<T>& x, const random_access_iterator<U>& y)
{
return y < x;
}
template <class T, class U>
TEST_CONSTEXPR_CXX14
bool operator>=(const random_access_iterator<T>& x, const random_access_iterator<U>& y)
{
return !(x < y);
}
template <class T, class U>
TEST_CONSTEXPR_CXX14
typename std::iterator_traits<T>::difference_type
operator-(const random_access_iterator<T>& x, const random_access_iterator<U>& y)
{
return x.base() - y.base();
}
#if TEST_STD_VER > 17
template <class It>
class contiguous_iterator
{
static_assert(std::is_pointer_v<It>, "Things probably break in this case");
It it_;
template <class U> friend class contiguous_iterator;
public:
typedef std::contiguous_iterator_tag iterator_category;
typedef typename std::iterator_traits<It>::value_type value_type;
typedef typename std::iterator_traits<It>::difference_type difference_type;
typedef It pointer;
typedef typename std::iterator_traits<It>::reference reference;
typedef typename std::remove_pointer<It>::type element_type;
TEST_CONSTEXPR_CXX14 It base() const {return it_;}
TEST_CONSTEXPR_CXX14 contiguous_iterator() : it_() {}
explicit TEST_CONSTEXPR_CXX14 contiguous_iterator(It it) : it_(it) {}
template <class U>
TEST_CONSTEXPR_CXX14 contiguous_iterator(const contiguous_iterator<U>& u) : it_(u.it_) {}
TEST_CONSTEXPR_CXX14 reference operator*() const {return *it_;}
TEST_CONSTEXPR_CXX14 pointer operator->() const {return it_;}
TEST_CONSTEXPR_CXX14 contiguous_iterator& operator++() {++it_; return *this;}
TEST_CONSTEXPR_CXX14 contiguous_iterator operator++(int)
{contiguous_iterator tmp(*this); ++(*this); return tmp;}
TEST_CONSTEXPR_CXX14 contiguous_iterator& operator--() {--it_; return *this;}
TEST_CONSTEXPR_CXX14 contiguous_iterator operator--(int)
{contiguous_iterator tmp(*this); --(*this); return tmp;}
TEST_CONSTEXPR_CXX14 contiguous_iterator& operator+=(difference_type n) {it_ += n; return *this;}
TEST_CONSTEXPR_CXX14 contiguous_iterator operator+(difference_type n) const
{contiguous_iterator tmp(*this); tmp += n; return tmp;}
friend TEST_CONSTEXPR_CXX14 contiguous_iterator operator+(difference_type n, contiguous_iterator x)
{x += n; return x;}
TEST_CONSTEXPR_CXX14 contiguous_iterator& operator-=(difference_type n) {return *this += -n;}
TEST_CONSTEXPR_CXX14 contiguous_iterator operator-(difference_type n) const
{contiguous_iterator tmp(*this); tmp -= n; return tmp;}
TEST_CONSTEXPR_CXX14 reference operator[](difference_type n) const {return it_[n];}
friend TEST_CONSTEXPR_CXX14
difference_type operator-(const contiguous_iterator& x, const contiguous_iterator& y) {
return x.base() - y.base();
}
friend TEST_CONSTEXPR_CXX14
difference_type operator<(const contiguous_iterator& x, const contiguous_iterator& y) {
return x.base() < y.base();
}
friend TEST_CONSTEXPR_CXX14
difference_type operator>(const contiguous_iterator& x, const contiguous_iterator& y) {
return x.base() > y.base();
}
friend TEST_CONSTEXPR_CXX14
difference_type operator<=(const contiguous_iterator& x, const contiguous_iterator& y) {
return x.base() <= y.base();
}
friend TEST_CONSTEXPR_CXX14
difference_type operator>=(const contiguous_iterator& x, const contiguous_iterator& y) {
return x.base() >= y.base();
}
friend TEST_CONSTEXPR_CXX14
difference_type operator==(const contiguous_iterator& x, const contiguous_iterator& y) {
return x.base() == y.base();
}
friend TEST_CONSTEXPR_CXX14
difference_type operator!=(const contiguous_iterator& x, const contiguous_iterator& y) {
return x.base() != y.base();
}
friend TEST_CONSTEXPR It base(const contiguous_iterator& i) { return i.it_; }
template <class T>
void operator,(T const &) = delete;
};
#endif
template <class Iter> // ADL base() for everything else (including pointers)
TEST_CONSTEXPR_CXX14 Iter base(Iter i) { return i; }
template <typename T>
struct ThrowingIterator {
typedef std::bidirectional_iterator_tag iterator_category;
typedef ptrdiff_t difference_type;
typedef const T value_type;
typedef const T * pointer;
typedef const T & reference;
enum ThrowingAction { TAIncrement, TADecrement, TADereference, TAAssignment, TAComparison };
TEST_CONSTEXPR ThrowingIterator()
: begin_(nullptr), end_(nullptr), current_(nullptr), action_(TADereference), index_(0) {}
TEST_CONSTEXPR explicit ThrowingIterator(const T* first, const T* last, int index = 0,
ThrowingAction action = TADereference)
: begin_(first), end_(last), current_(first), action_(action), index_(index) {}
TEST_CONSTEXPR ThrowingIterator(const ThrowingIterator &rhs)
: begin_(rhs.begin_), end_(rhs.end_), current_(rhs.current_), action_(rhs.action_), index_(rhs.index_) {}
TEST_CONSTEXPR_CXX14 ThrowingIterator& operator=(const ThrowingIterator& rhs) {
if (action_ == TAAssignment && --index_ < 0) {
#ifndef TEST_HAS_NO_EXCEPTIONS
throw std::runtime_error("throw from iterator assignment");
#else
assert(false);
#endif
}
begin_ = rhs.begin_;
end_ = rhs.end_;
current_ = rhs.current_;
action_ = rhs.action_;
index_ = rhs.index_;
return *this;
}
TEST_CONSTEXPR_CXX14 reference operator*() const {
if (action_ == TADereference && --index_ < 0) {
#ifndef TEST_HAS_NO_EXCEPTIONS
throw std::runtime_error("throw from iterator dereference");
#else
assert(false);
#endif
}
return *current_;
}
TEST_CONSTEXPR_CXX14 ThrowingIterator& operator++() {
if (action_ == TAIncrement && --index_ < 0) {
#ifndef TEST_HAS_NO_EXCEPTIONS
throw std::runtime_error("throw from iterator increment");
#else
assert(false);
#endif
}
++current_;
return *this;
}
TEST_CONSTEXPR_CXX14 ThrowingIterator operator++(int) {
ThrowingIterator temp = *this;
++(*this);
return temp;
}
TEST_CONSTEXPR_CXX14 ThrowingIterator& operator--() {
if (action_ == TADecrement && --index_ < 0) {
#ifndef TEST_HAS_NO_EXCEPTIONS
throw std::runtime_error("throw from iterator decrement");
#else
assert(false);
#endif
}
--current_;
return *this;
}
TEST_CONSTEXPR_CXX14 ThrowingIterator operator--(int) {
ThrowingIterator temp = *this;
--(*this);
return temp;
}
TEST_CONSTEXPR_CXX14 friend bool operator==(const ThrowingIterator& a, const ThrowingIterator& b) {
if (a.action_ == TAComparison && --a.index_ < 0) {
#ifndef TEST_HAS_NO_EXCEPTIONS
throw std::runtime_error("throw from iterator comparison");
#else
assert(false);
#endif
}
bool atEndL = a.current_ == a.end_;
bool atEndR = b.current_ == b.end_;
if (atEndL != atEndR) return false; // one is at the end (or empty), the other is not.
if (atEndL) return true; // both are at the end (or empty)
return a.current_ == b.current_;
}
TEST_CONSTEXPR friend bool operator!=(const ThrowingIterator& a, const ThrowingIterator& b) {
return !(a == b);
}
template <class T2>
void operator,(T2 const &) = delete;
private:
const T* begin_;
const T* end_;
const T* current_;
ThrowingAction action_;
mutable int index_;
};
template <typename T>
struct NonThrowingIterator {
typedef std::bidirectional_iterator_tag iterator_category;
typedef ptrdiff_t difference_type;
typedef const T value_type;
typedef const T * pointer;
typedef const T & reference;
NonThrowingIterator()
: begin_(nullptr), end_(nullptr), current_(nullptr) {}
explicit NonThrowingIterator(const T *first, const T *last)
: begin_(first), end_(last), current_(first) {}
NonThrowingIterator(const NonThrowingIterator& rhs)
: begin_(rhs.begin_), end_(rhs.end_), current_(rhs.current_) {}
NonThrowingIterator& operator=(const NonThrowingIterator& rhs) TEST_NOEXCEPT {
begin_ = rhs.begin_;
end_ = rhs.end_;
current_ = rhs.current_;
return *this;
}
reference operator*() const TEST_NOEXCEPT {
return *current_;
}
NonThrowingIterator& operator++() TEST_NOEXCEPT {
++current_;
return *this;
}
NonThrowingIterator operator++(int) TEST_NOEXCEPT {
NonThrowingIterator temp = *this;
++(*this);
return temp;
}
NonThrowingIterator & operator--() TEST_NOEXCEPT {
--current_;
return *this;
}
NonThrowingIterator operator--(int) TEST_NOEXCEPT {
NonThrowingIterator temp = *this;
--(*this);
return temp;
}
friend bool operator==(const NonThrowingIterator& a, const NonThrowingIterator& b) TEST_NOEXCEPT {
bool atEndL = a.current_ == a.end_;
bool atEndR = b.current_ == b.end_;
if (atEndL != atEndR) return false; // one is at the end (or empty), the other is not.
if (atEndL) return true; // both are at the end (or empty)
return a.current_ == b.current_;
}
friend bool operator!=(const NonThrowingIterator& a, const NonThrowingIterator& b) TEST_NOEXCEPT {
return !(a == b);
}
template <class T2>
void operator,(T2 const &) = delete;
private:
const T *begin_;
const T *end_;
const T *current_;
};
#ifdef TEST_SUPPORTS_RANGES
template <class It>
class cpp20_input_iterator
{
It it_;
public:
using value_type = std::iter_value_t<It>;
using difference_type = std::iter_difference_t<It>;
using iterator_concept = std::input_iterator_tag;
constexpr explicit cpp20_input_iterator(It it) : it_(it) {}
cpp20_input_iterator(cpp20_input_iterator&&) = default;
cpp20_input_iterator& operator=(cpp20_input_iterator&&) = default;
constexpr decltype(auto) operator*() const { return *it_; }
constexpr cpp20_input_iterator& operator++() { ++it_; return *this; }
constexpr void operator++(int) { ++it_; }
constexpr const It& base() const& { return it_; }
constexpr It base() && { return std::move(it_); }
friend constexpr It base(const cpp20_input_iterator& i) { return i.it_; }
template <class T>
void operator,(T const &) = delete;
};
template <std::input_or_output_iterator I>
struct iterator_concept {
using type = std::output_iterator_tag;
};
template <std::input_iterator I>
struct iterator_concept<I> {
using type = std::input_iterator_tag;
};
template <std::forward_iterator I>
struct iterator_concept<I> {
using type = std::forward_iterator_tag;
};
template <std::bidirectional_iterator I>
struct iterator_concept<I> {
using type = std::bidirectional_iterator_tag;
};
template <std::random_access_iterator I>
struct iterator_concept<I> {
using type = std::random_access_iterator_tag;
};
template<std::contiguous_iterator I>
struct iterator_concept<I> {
using type = std::contiguous_iterator_tag;
};
template <std::input_or_output_iterator I>
using iterator_concept_t = typename iterator_concept<I>::type;
template<std::input_or_output_iterator>
struct iter_value_or_void { using type = void; };
template<std::input_iterator I>
struct iter_value_or_void<I> {
using type = std::iter_value_t<I>;
};
// Iterator adaptor that counts the number of times the iterator has had a successor/predecessor
// operation called. Has two recorders:
// * `stride_count`, which records the total number of calls to an op++, op--, op+=, or op-=.
// * `stride_displacement`, which records the displacement of the calls. This means that both
// op++/op+= will increase the displacement counter by 1, and op--/op-= will decrease the
// displacement counter by 1.
template <std::input_or_output_iterator I>
class stride_counting_iterator {
public:
using value_type = typename iter_value_or_void<I>::type;
using difference_type = std::iter_difference_t<I>;
using iterator_concept = iterator_concept_t<I>;
stride_counting_iterator() = default;
constexpr explicit stride_counting_iterator(I current) : base_(std::move(current)) {}
constexpr const I& base() const& { return base_; }
constexpr I base() && { return std::move(base_); }
constexpr difference_type stride_count() const { return stride_count_; }
constexpr difference_type stride_displacement() const { return stride_displacement_; }
constexpr decltype(auto) operator*() const { return *base_; }
constexpr decltype(auto) operator[](difference_type const n) const { return base_[n]; }
constexpr stride_counting_iterator& operator++() {
++base_;
++stride_count_;
++stride_displacement_;
return *this;
}
constexpr void operator++(int) { ++*this; }
constexpr stride_counting_iterator operator++(int)
requires std::forward_iterator<I>
{
auto temp = *this;
++*this;
return temp;
}
constexpr stride_counting_iterator& operator--()
requires std::bidirectional_iterator<I>
{
--base_;
++stride_count_;
--stride_displacement_;
return *this;
}
constexpr stride_counting_iterator operator--(int)
requires std::bidirectional_iterator<I>
{
auto temp = *this;
--*this;
return temp;
}
constexpr stride_counting_iterator& operator+=(difference_type const n)
requires std::random_access_iterator<I>
{
base_ += n;
++stride_count_;
++stride_displacement_;
return *this;
}
constexpr stride_counting_iterator& operator-=(difference_type const n)
requires std::random_access_iterator<I>
{
base_ -= n;
++stride_count_;
--stride_displacement_;
return *this;
}
friend constexpr stride_counting_iterator operator+(stride_counting_iterator i, difference_type const n)
requires std::random_access_iterator<I>
{
return i += n;
}
friend constexpr stride_counting_iterator operator+(difference_type const n, stride_counting_iterator i)
requires std::random_access_iterator<I>
{
return i += n;
}
friend constexpr stride_counting_iterator operator-(stride_counting_iterator i, difference_type const n)
requires std::random_access_iterator<I>
{
return i -= n;
}
friend constexpr difference_type operator-(stride_counting_iterator const& x, stride_counting_iterator const& y)
requires std::sized_sentinel_for<I, I>
{
return x.base() - y.base();
}
constexpr bool operator==(stride_counting_iterator const& other) const
requires std::sentinel_for<I, I>
{
return base_ == other.base_;
}
template <std::sentinel_for<I> S>
constexpr bool operator==(S const last) const
{
return base_ == last;
}
friend constexpr bool operator<(stride_counting_iterator const& x, stride_counting_iterator const& y)
requires std::random_access_iterator<I>
{
return x.base_ < y.base_;
}
friend constexpr bool operator>(stride_counting_iterator const& x, stride_counting_iterator const& y)
requires std::random_access_iterator<I>
{
return y < x;
}
friend constexpr bool operator<=(stride_counting_iterator const& x, stride_counting_iterator const& y)
requires std::random_access_iterator<I>
{
return !(y < x);
}
friend constexpr bool operator>=(stride_counting_iterator const& x, stride_counting_iterator const& y)
requires std::random_access_iterator<I>
{
return !(x < y);
}
template <class T>
void operator,(T const &) = delete;
private:
I base_;
difference_type stride_count_ = 0;
difference_type stride_displacement_ = 0;
};
template <class It>
class sentinel_wrapper {
public:
explicit sentinel_wrapper() = default;
constexpr explicit sentinel_wrapper(const It& it) : base_(base(it)) {}
constexpr bool operator==(const It& other) const { return base_ == base(other); }
friend constexpr It base(const sentinel_wrapper& s) { return It(s.base_); }
private:
decltype(base(std::declval<It>())) base_;
};
template <class It>
class sized_sentinel {
public:
explicit sized_sentinel() = default;
constexpr explicit sized_sentinel(const It& it) : base_(base(it)) {}
constexpr bool operator==(const It& other) const { return base_ == base(other); }
friend constexpr auto operator-(const sized_sentinel& s, const It& i) { return s.base_ - base(i); }
friend constexpr auto operator-(const It& i, const sized_sentinel& s) { return base(i) - s.base_; }
friend constexpr It base(const sized_sentinel& s) { return It(s.base_); }
private:
decltype(base(std::declval<It>())) base_;
};
template <class It>
class three_way_contiguous_iterator
{
static_assert(std::is_pointer_v<It>, "Things probably break in this case");
It it_;
template <class U> friend class three_way_contiguous_iterator;
public:
typedef std::contiguous_iterator_tag iterator_category;
typedef typename std::iterator_traits<It>::value_type value_type;
typedef typename std::iterator_traits<It>::difference_type difference_type;
typedef It pointer;
typedef typename std::iterator_traits<It>::reference reference;
typedef typename std::remove_pointer<It>::type element_type;
constexpr It base() const {return it_;}
constexpr three_way_contiguous_iterator() : it_() {}
constexpr explicit three_way_contiguous_iterator(It it) : it_(it) {}
template <class U>
constexpr three_way_contiguous_iterator(const three_way_contiguous_iterator<U>& u) : it_(u.it_) {}
constexpr reference operator*() const {return *it_;}
constexpr pointer operator->() const {return it_;}
constexpr three_way_contiguous_iterator& operator++() {++it_; return *this;}
constexpr three_way_contiguous_iterator operator++(int) {auto tmp = *this; ++(*this); return tmp;}
constexpr three_way_contiguous_iterator& operator--() {--it_; return *this;}
constexpr three_way_contiguous_iterator operator--(int) {auto tmp = *this; --(*this); return tmp;}
constexpr three_way_contiguous_iterator& operator+=(difference_type n) {it_ += n; return *this;}
constexpr auto operator+(difference_type n) const {auto tmp = *this; tmp += n; return tmp;}
friend constexpr auto operator+(difference_type n, three_way_contiguous_iterator x) {x += n; return x;}
constexpr three_way_contiguous_iterator& operator-=(difference_type n) {return *this += -n;}
constexpr auto operator-(difference_type n) const {auto tmp = *this; tmp -= n; return tmp;}
constexpr reference operator[](difference_type n) const {return it_[n];}
friend constexpr
difference_type operator-(const three_way_contiguous_iterator& x, const three_way_contiguous_iterator& y) {
return x.base() - y.base();
}
friend auto operator<=>(const three_way_contiguous_iterator&, const three_way_contiguous_iterator&) = default;
template <class T>
void operator,(T const &) = delete;
};
#endif // TEST_STD_VER > 17 && defined(__cpp_lib_concepts)
#endif // SUPPORT_TEST_ITERATORS_H
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