Added iterators.

This commit is contained in:
Neil MacIntosh 2016-05-29 13:52:28 -07:00
parent 85939048b4
commit d9d6ff0121
2 changed files with 179 additions and 513 deletions

View File

@ -137,6 +137,126 @@ struct is_allowed_element_type_conversion<From, const char>
{
};
template <class Span>
class span_iterator
: public std::iterator<std::random_access_iterator_tag, typename Span::element_type>
{
using Base = std::iterator<std::random_access_iterator_tag, typename Span::element_type>;
public:
using typename Base::reference;
using typename Base::pointer;
using typename Base::difference_type;
span_iterator() : span_iterator(nullptr, 0) {}
span_iterator(const Span* span, typename Span::index_type index) : span_(span), index_(index)
{
Expects(span == nullptr || (index_ >= 0 && index <= span_->length()));
}
reference operator*() const { Expects(span_); return (*span_)[index_]; }
pointer operator->() const { Expects(span_); return &((*span_)[index_]); }
span_iterator& operator++() noexcept
{
Expects(span_ && index_ >= 0 && index_ < span_->length());
++index_;
return *this;
}
span_iterator operator++(int) noexcept
{
auto ret = *this;
++(*this);
return ret;
}
span_iterator& operator--() noexcept
{
Expects(span_ && index > 0 && index_ <= span_->length());
--index_;
return *this;
}
span_iterator operator--(int) noexcept
{
auto ret = *this;
--(*this);
return ret;
}
span_iterator operator+(difference_type n) const noexcept
{
auto ret{*this};
return ret += n;
}
span_iterator& operator+=(difference_type n) noexcept
{
index_ += n;
Expects(span_ && index_ >= 0 && index_ <= span_->length());
return *this;
}
span_iterator operator-(difference_type n) const noexcept
{
auto ret{*this};
return ret -= n;
}
span_iterator& operator-=(difference_type n) noexcept
{
return *this += -n;
}
difference_type operator-(const span_iterator& rhs) const noexcept
{
Expects(span_ == rhs.span_);
return index_ - rhs.index_;
}
reference operator[](difference_type n) const noexcept
{ return *(*this + n); }
bool operator==(const span_iterator& rhs) const noexcept
{ return span_ == rhs.span_ && index_ == rhs.index_; }
bool operator!=(const span_iterator& rhs) const noexcept { return !(*this == rhs); }
bool operator<(const span_iterator& rhs) const noexcept
{
Expects(span_ == rhs.span_);
return index_ < rhs.index_;
}
bool operator<=(const span_iterator& rhs) const noexcept { return !(rhs < *this); }
bool operator>(const span_iterator& rhs) const noexcept { return rhs < *this; }
bool operator>=(const span_iterator& rhs) const noexcept { return !(rhs > *this); }
void swap(span_iterator& rhs) noexcept
{
std::swap(index_, rhs.index_);
std::swap(m_span, rhs.m_span);
}
private:
const Span* span_;
ptrdiff_t index_;
};
template <typename Span>
span_iterator<Span> operator+(typename span_iterator<Span>::difference_type n,
const span_iterator<Span>& rhs) noexcept
{ return rhs + n; }
template <typename Span>
span_iterator<Span> operator-(typename span_iterator<Span>::difference_type n,
const span_iterator<Span>& rhs) noexcept
{
return rhs - n;
}
} // namespace details
@ -155,12 +275,10 @@ public:
using index_type = std::ptrdiff_t;
using pointer = element_type*;
using reference = element_type&;
#if 0 // TODO
using iterator = /*implementation-defined */;
using const_iterator = /* implementation-defined */;
using iterator = details::span_iterator<span<ElementType, Extent>>;
using reverse_iterator = std::reverse_iterator<iterator>;
using const_reverse_iterator = std::reverse_iterator<const_iterator>;
#endif
constexpr static const index_type extent = Extent;
// [span.cons], span constructors, copy, assignment, and destructor
@ -228,8 +346,7 @@ public:
>
constexpr span(span<OtherElementType, OtherExtent>&& other)
: storage_(reinterpret_cast<pointer>(other.data()), other.length())
{
}
{}
~span() noexcept = default;
constexpr span& operator=(const span& other) noexcept = default;
@ -293,20 +410,14 @@ public:
}
constexpr reference operator()(index_type idx) const { return this->operator[](idx); }
constexpr pointer data() const noexcept { return storage_.data(); }
#if 0 // TODO
// [span.iter], span iterator support
iterator begin() const noexcept;
iterator end() const noexcept;
iterator begin() const noexcept { return {this, 0}; }
iterator end() const noexcept { return {this, length()}; }
const_iterator cbegin() const noexcept;
const_iterator cend() const noexcept;
reverse_iterator rbegin() const noexcept { return {this, length()}; }
reverse_iterator rend() const noexcept { return {this, 0}; }
reverse_iterator rbegin() const noexcept;
reverse_iterator rend() const noexcept;
const_reverse_iterator crbegin() const noexcept;
const_reverse_iterator crend() const noexcept;
#endif
private:
template <index_type Extent>
class extent_type;

View File

@ -751,6 +751,56 @@ SUITE(span_tests)
CHECK_THROW(s(2) ,fail_fast);
}
}
TEST(iterator)
{
span<int>::iterator it1;
span<int>::iterator it2;
CHECK(it1 == it2);
}
TEST(begin_end)
{
{
int a[] = { 1, 2, 3, 4 };
span<int> s = a;
span<int>::iterator it = s.begin();
auto first = it;
CHECK(it == first);
CHECK(*it == 1);
span<int>::iterator beyond = s.end();
CHECK(it != beyond);
CHECK_THROW(*beyond, fail_fast);
CHECK(beyond - first == 4);
CHECK(first - first == 0);
CHECK(beyond - beyond == 0);
++it;
CHECK(it - first == 1);
CHECK(*it == 2);
*it = 22;
CHECK(*it == 22);
CHECK(beyond - it == 3);
it = first;
CHECK(it == first);
while (it != s.end())
{
*it = 5;
++it;
}
CHECK(it == beyond);
CHECK(it - beyond == 0);
for (auto& n : s)
CHECK(n == 5);
}
}
#if 0
TEST(comparison_operators)
{
@ -864,476 +914,6 @@ SUITE(span_tests)
}
}
#if 0
TEST(basics)
{
auto ptr = as_span(new int[10], 10);
fill(ptr.begin(), ptr.end(), 99);
for (int num : ptr) {
CHECK(num == 99);
}
delete[] ptr.data();
}
TEST(bounds_checks)
{
int arr[10][2];
auto av = as_span(arr);
fill(begin(av), end(av), 0);
av[2][0] = 1;
av[1][1] = 3;
// out of bounds
CHECK_THROW(av[1][3] = 3, fail_fast);
CHECK_THROW((av[{1, 3}] = 3), fail_fast);
CHECK_THROW(av[10][2], fail_fast);
CHECK_THROW((av[{10, 2}]), fail_fast);
}
void overloaded_func(span<const int, dynamic_range, 3, 5> exp, int expected_value)
{
for (auto val : exp) {
CHECK(val == expected_value);
}
}
void overloaded_func(span<const char, dynamic_range, 3, 5> exp, char expected_value)
{
for (auto val : exp) {
CHECK(val == expected_value);
}
}
void fixed_func(span<int, 3, 3, 5> exp, int expected_value)
{
for (auto val : exp) {
CHECK(val == expected_value);
}
}
TEST(span_parameter_test)
{
auto data = new int[4][3][5];
auto av = as_span(data, 4);
CHECK(av.size() == 60);
fill(av.begin(), av.end(), 34);
int count = 0;
for_each(av.rbegin(), av.rend(), [&](int val) { count += val; });
CHECK(count == 34 * 60);
overloaded_func(av, 34);
overloaded_func(as_span(av, dim<>(4), dim<>(3), dim<>(5)), 34);
// fixed_func(av, 34);
delete[] data;
}
TEST(md_access)
{
auto width = 5, height = 20;
auto imgSize = width * height;
auto image_ptr = new int[imgSize][3];
// size check will be done
auto image_view =
as_span(as_span(image_ptr, imgSize), dim<>(height), dim<>(width), dim<3>());
iota(image_view.begin(), image_view.end(), 1);
int expected = 0;
for (auto i = 0; i < height; i++) {
for (auto j = 0; j < width; j++) {
CHECK(expected + 1 == image_view[i][j][0]);
CHECK(expected + 2 == image_view[i][j][1]);
CHECK(expected + 3 == image_view[i][j][2]);
auto val = image_view[{i, j, 0}];
CHECK(expected + 1 == val);
val = image_view[{i, j, 1}];
CHECK(expected + 2 == val);
val = image_view[{i, j, 2}];
CHECK(expected + 3 == val);
expected += 3;
}
}
}
TEST(as_span)
{
{
int* arr = new int[150];
auto av = as_span(arr, dim<10>(), dim<>(3), dim<5>());
fill(av.begin(), av.end(), 24);
overloaded_func(av, 24);
delete[] arr;
array<int, 15> stdarr{0};
auto av2 = as_span(stdarr);
overloaded_func(as_span(av2, dim<>(1), dim<3>(), dim<5>()), 0);
string str = "ttttttttttttttt"; // size = 15
auto t = str.data();
(void) t;
auto av3 = as_span(str);
overloaded_func(as_span(av3, dim<>(1), dim<3>(), dim<5>()), 't');
}
{
string str;
span<char> strspan = as_span(str);
(void) strspan;
const string cstr;
span<const char> cstrspan = as_span(cstr);
(void) cstrspan;
}
{
int a[3][4][5];
auto av = as_span(a);
const int(*b)[4][5];
b = a;
auto bv = as_span(b, 3);
CHECK(av == bv);
const std::array<double, 3> arr = {0.0, 0.0, 0.0};
auto cv = as_span(arr);
(void) cv;
vector<float> vec(3);
auto dv = as_span(vec);
(void) dv;
#ifdef CONFIRM_COMPILATION_ERRORS
auto dv2 = as_span(std::move(vec));
#endif
}
}
TEST(empty_spans)
{
{
span<int, 0> empty_av(nullptr);
CHECK(empty_av.bounds().index_bounds() == index<1>{0});
CHECK_THROW(empty_av[0], fail_fast);
CHECK_THROW(empty_av.begin()[0], fail_fast);
CHECK_THROW(empty_av.cbegin()[0], fail_fast);
for (auto& v : empty_av) {
(void) v;
CHECK(false);
}
}
{
span<int> empty_av = {};
CHECK(empty_av.bounds().index_bounds() == index<1>{0});
CHECK_THROW(empty_av[0], fail_fast);
CHECK_THROW(empty_av.begin()[0], fail_fast);
CHECK_THROW(empty_av.cbegin()[0], fail_fast);
for (auto& v : empty_av) {
(void) v;
CHECK(false);
}
}
}
TEST(index_constructor)
{
auto arr = new int[8];
for (int i = 0; i < 4; ++i) {
arr[2 * i] = 4 + i;
arr[2 * i + 1] = i;
}
span<int, dynamic_range> av(arr, 8);
ptrdiff_t a[1] = {0};
index<1> i = a;
CHECK(av[i] == 4);
auto av2 = as_span(av, dim<4>(), dim<>(2));
ptrdiff_t a2[2] = {0, 1};
index<2> i2 = a2;
CHECK(av2[i2] == 0);
CHECK(av2[0][i] == 4);
delete[] arr;
}
TEST(index_constructors)
{
{
// components of the same type
index<3> i1(0, 1, 2);
CHECK(i1[0] == 0);
// components of different types
size_t c0 = 0;
size_t c1 = 1;
index<3> i2(c0, c1, 2);
CHECK(i2[0] == 0);
// from array
index<3> i3 = {0, 1, 2};
CHECK(i3[0] == 0);
// from other index of the same size type
index<3> i4 = i3;
CHECK(i4[0] == 0);
// default
index<3> i7;
CHECK(i7[0] == 0);
// default
index<3> i9 = {};
CHECK(i9[0] == 0);
}
{
// components of the same type
index<1> i1(0);
CHECK(i1[0] == 0);
// components of different types
size_t c0 = 0;
index<1> i2(c0);
CHECK(i2[0] == 0);
// from array
index<1> i3 = {0};
CHECK(i3[0] == 0);
// from int
index<1> i4 = 0;
CHECK(i4[0] == 0);
// from other index of the same size type
index<1> i5 = i3;
CHECK(i5[0] == 0);
// default
index<1> i8;
CHECK(i8[0] == 0);
// default
index<1> i9 = {};
CHECK(i9[0] == 0);
}
#ifdef CONFIRM_COMPILATION_ERRORS
{
index<3> i1(0, 1);
index<3> i2(0, 1, 2, 3);
index<3> i3 = {0};
index<3> i4 = {0, 1, 2, 3};
index<1> i5 = {0, 1};
}
#endif
}
TEST(index_operations)
{
ptrdiff_t a[3] = {0, 1, 2};
ptrdiff_t b[3] = {3, 4, 5};
index<3> i = a;
index<3> j = b;
CHECK(i[0] == 0);
CHECK(i[1] == 1);
CHECK(i[2] == 2);
{
index<3> k = i + j;
CHECK(i[0] == 0);
CHECK(i[1] == 1);
CHECK(i[2] == 2);
CHECK(k[0] == 3);
CHECK(k[1] == 5);
CHECK(k[2] == 7);
}
{
index<3> k = i * 3;
CHECK(i[0] == 0);
CHECK(i[1] == 1);
CHECK(i[2] == 2);
CHECK(k[0] == 0);
CHECK(k[1] == 3);
CHECK(k[2] == 6);
}
{
index<3> k = 3 * i;
CHECK(i[0] == 0);
CHECK(i[1] == 1);
CHECK(i[2] == 2);
CHECK(k[0] == 0);
CHECK(k[1] == 3);
CHECK(k[2] == 6);
}
{
index<2> k = details::shift_left(i);
CHECK(i[0] == 0);
CHECK(i[1] == 1);
CHECK(i[2] == 2);
CHECK(k[0] == 1);
CHECK(k[1] == 2);
}
}
void iterate_second_column(span<int, dynamic_range, dynamic_range> av)
{
auto length = av.size() / 2;
// view to the second column
auto section = av.section({0, 1}, {length, 1});
CHECK(section.size() == length);
for (auto i = 0; i < section.size(); ++i) {
CHECK(section[i][0] == av[i][1]);
}
for (auto i = 0; i < section.size(); ++i) {
auto idx = index<2>{i, 0}; // avoid braces inside the CHECK macro
CHECK(section[idx] == av[i][1]);
}
CHECK(section.bounds().index_bounds()[0] == length);
CHECK(section.bounds().index_bounds()[1] == 1);
for (auto i = 0; i < section.bounds().index_bounds()[0]; ++i) {
for (auto j = 0; j < section.bounds().index_bounds()[1]; ++j) {
auto idx = index<2>{i, j}; // avoid braces inside the CHECK macro
CHECK(section[idx] == av[i][1]);
}
}
size_t check_sum = 0;
for (auto i = 0; i < length; ++i) {
check_sum += av[i][1];
}
{
auto idx = 0;
size_t sum = 0;
for (auto num : section) {
CHECK(num == av[idx][1]);
sum += num;
idx++;
}
CHECK(sum == check_sum);
}
{
size_t idx = length - 1;
size_t sum = 0;
for (auto iter = section.rbegin(); iter != section.rend(); ++iter) {
CHECK(*iter == av[idx][1]);
sum += *iter;
idx--;
}
CHECK(sum == check_sum);
}
}
TEST(span_section_iteration)
{
int arr[4][2] = {{4, 0}, {5, 1}, {6, 2}, {7, 3}};
// static bounds
{
span<int, 4, 2> av = arr;
iterate_second_column(av);
}
// first bound is dynamic
{
span<int, dynamic_range, 2> av = arr;
iterate_second_column(av);
}
// second bound is dynamic
{
span<int, 4, dynamic_range> av = arr;
iterate_second_column(av);
}
// both bounds are dynamic
{
span<int, dynamic_range, dynamic_range> av = arr;
iterate_second_column(av);
}
}
TEST(dynamic_span_section_iteration)
{
auto height = 4, width = 2;
auto size = height * width;
auto arr = new int[size];
for (auto i = 0; i < size; ++i) {
arr[i] = i;
}
auto av = as_span(arr, size);
// first bound is dynamic
{
span<int, dynamic_range, 2> av2 = as_span(av, dim<>(height), dim<>(width));
iterate_second_column(av2);
}
// second bound is dynamic
{
span<int, 4, dynamic_range> av2 = as_span(av, dim<>(height), dim<>(width));
iterate_second_column(av2);
}
// both bounds are dynamic
{
span<int, dynamic_range, dynamic_range> av2 = as_span(av, dim<>(height), dim<>(width));
iterate_second_column(av2);
}
delete[] arr;
}
TEST(span_structure_size)
{
double(*arr)[3][4] = new double[100][3][4];
span<double, dynamic_range, 3, 4> av1(arr, 10);
struct EffectiveStructure
{
double* v1;
ptrdiff_t v2;
};
CHECK(sizeof(av1) == sizeof(EffectiveStructure));
CHECK_THROW(av1[10][3][4], fail_fast);
span<const double, dynamic_range, 6, 4> av2 = as_span(av1, dim<>(5), dim<6>(), dim<4>());
(void) av2;
}
TEST(fixed_size_conversions)
{
int arr[] = {1, 2, 3, 4};
@ -1458,31 +1038,6 @@ SUITE(span_tests)
}
}
TEST(iterator)
{
int a[] = {1, 2, 3, 4};
{
span<int, dynamic_range> av = a;
auto wav = as_writeable_bytes(av);
for (auto& b : wav) {
b = byte(0);
}
for (size_t i = 0; i < 4; ++i) {
CHECK(a[i] == 0);
}
}
{
span<int, dynamic_range> av = a;
for (auto& n : av) {
n = 1;
}
for (size_t i = 0; i < 4; ++i) {
CHECK(a[i] == 1);
}
}
}
#endif
}