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Update array_view to N4494
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UncleHandsome committed May 5, 2015
1 parent 8600680 commit d8f4c71
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Showing 2 changed files with 27 additions and 69 deletions.
89 changes: 20 additions & 69 deletions include/array_view
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Original file line number Diff line number Diff line change
Expand Up @@ -22,14 +22,6 @@ namespace std
return data[offset]; \
}

template <class _Indx, class ArrayType> struct decompose {};

template <int ...N, class ArrayType>
struct decompose<__indices<N...>, ArrayType> {
static inline const bounds<sizeof...(N)> call() {
return move(bounds<sizeof...(N)>{extent<ArrayType, N>::value...});
}
};

template <size_t N>
static inline offset<N> get_stride(const bounds<N>& bnd)
Expand All @@ -42,7 +34,7 @@ static inline offset<N> get_stride(const bounds<N>& bnd)
}


template <class T, int Rank> class strided_array_view;
template <class T, size_t Rank> class strided_array_view;

template <typename T>
struct __has_data
Expand All @@ -67,17 +59,17 @@ public:
};

template <typename T>
struct __is_container
struct __is_viewable
{
using _T = typename std::remove_reference<T>::type;
static const bool value = __has_size<_T>::value && __has_data<_T>::value;
};

template <class T, int Rank = 1>
template <class T, size_t Rank = 1>
class array_view {
public:
static constexpr int rank = Rank;
using offset_type = offset<Rank>;
static constexpr size_t rank = Rank;
using offset_type = offset<Rank>;
using bounds_type = bounds<Rank>;
using size_type = size_t;
using value_type = T;
Expand All @@ -86,10 +78,10 @@ public:

array_view() noexcept : data_(nullptr), bnd_(), stride_() {}

template <class Viewable, int N = Rank,
template <class Viewable, size_t N = Rank,
typename = typename enable_if<
(N == 1) &&
__is_container<Viewable>::value
__is_viewable<Viewable>::value
>::type
>
array_view(Viewable&& vw) : data_(vw.data()), bnd_(vw.size()), stride_() {
Expand All @@ -99,7 +91,7 @@ public:
typename remove_cv<T>::type>::value, "illegal Viewable");
}

template <class U, int AnyN, int N = Rank,
template <class U, size_t AnyN, size_t N = Rank,
typename = typename enable_if<
N == 1 &&
is_convertible<typename add_pointer<U>::type, pointer>::value &&
Expand All @@ -109,23 +101,12 @@ public:
array_view(const array_view<U, AnyN>& rhs) noexcept
: data_(rhs.data()), bnd_(rhs.size()), stride_(1) {}

template <class ArrayType,
int N = Rank,
typename = typename enable_if<
is_convertible<
typename add_pointer<typename remove_all_extents<ArrayType>::type>::type,
pointer
>::value &&
is_same<typename remove_cv<
typename remove_all_extents<ArrayType>::type>::type,
typename remove_cv<value_type>::type
>::value &&
std::rank<ArrayType>::value == N
>::type
template <size_t Extent,
size_t N = Rank,
typename = typename enable_if<N == 1>::type
>
array_view(ArrayType& arr) noexcept
: data_(reinterpret_cast<pointer>(arr)),
bnd_(decompose<typename __make_indices<Rank>::type, ArrayType>::call()), stride_(get_stride(bnd_)) {}
array_view(value_type (&arr)[Extent]) noexcept
: data_(arr), bnd_(Extent), stride_(get_stride(bnd_)) {}

template <class U,
typename = typename enable_if<
Expand All @@ -149,21 +130,6 @@ public:
array_view(pointer ptr, bounds_type bounds)
: data_(ptr), bnd_(bounds), stride_(get_stride(bounds)) {}

template <class U,
typename = typename enable_if<
is_convertible<typename add_pointer<U>::type, pointer>::value &&
is_same<
typename remove_cv<U>::type,
typename remove_cv<value_type>::type
>::value
>::type
>
array_view& operator=(const array_view<U, Rank>& rhs) noexcept {
data_ = rhs.data_;
bnd_ = rhs.bnd_;
stride_ = rhs.stride_;
}

bounds_type bounds() const noexcept { return bnd_; }
size_type size() const noexcept { return bnd_.size(); }
offset_type stride() const noexcept { return stride_; }
Expand All @@ -175,7 +141,7 @@ public:
}

// [arrayview.subview], array_view slicing and sectioning
template<int N = Rank, typename = typename enable_if<(N > 1)>::type>
template<size_t N = Rank, typename = typename enable_if<(N > 1)>::type>
array_view<T, Rank - 1>
operator[](ptrdiff_t slice) const {
assert(slice < bnd_[0]);
Expand All @@ -190,7 +156,7 @@ public:
for (auto i = 0; i < Rank; ++i)
assert(range[i] >= section_bnd[i]);
ptrdiff_t offset = 0;
for (int i = 0; i < Rank; ++i)
for (auto i = 0; i < Rank; ++i)
offset += origin[i] * stride_[i];
return strided_array_view<T, Rank>(data_ + offset, section_bnd, stride_);
}
Expand All @@ -204,11 +170,11 @@ private:
offset_type stride_;
};

template <class T, int Rank = 1>
template <class T, size_t Rank = 1>
class strided_array_view {
public:
// constants and types
static constexpr int rank = Rank;
static constexpr size_t rank = Rank;
using offset_type = offset<Rank>;
using bounds_type = bounds<Rank>;
using size_type = size_t;
Expand Down Expand Up @@ -245,21 +211,6 @@ public:
strided_array_view(pointer ptr, bounds_type bounds, offset_type stride)
: data_(ptr), bnd_(bounds), stride_(stride) {}

template <class U,
typename = typename enable_if<
is_convertible<typename add_pointer<U>::type, pointer>::value &&
is_same<
typename remove_cv<U>::type,
typename remove_cv<value_type>::type
>::value
>::type
>
strided_array_view& operator=(const strided_array_view<U, Rank>& rhs) noexcept {
data_ = rhs.data_;
bnd_ = rhs.bnd_;
stride_ = rhs.stride_;
}

bounds_type bounds() const noexcept { return bnd_; }
size_type size() const noexcept { return bnd_.size(); }
offset_type stride() const noexcept { return stride_; }
Expand All @@ -269,7 +220,7 @@ public:
VIEW_ACCESS(data_, idx, stride(), Rank);
}

template<int N = Rank, typename = typename enable_if<(N > 1)>::type>
template<size_t N = Rank, typename = typename enable_if<(N > 1)>::type>
strided_array_view<T, Rank - 1>
operator[](ptrdiff_t slice) const {
assert(slice < bnd_[0]);
Expand All @@ -287,7 +238,7 @@ public:
for (auto i = 0; i < Rank; ++i)
assert(range[i] >= section_bnd[i]);
ptrdiff_t offset = 0;
for (int i = 0; i < Rank; ++i)
for (auto i = 0; i < Rank; ++i)
offset += origin[i] * stride_[i];
return strided_array_view<T, Rank>(data_ + offset, section_bnd, stride_);
}
Expand All @@ -296,7 +247,7 @@ public:

private:
static_assert(Rank >= 1, "Rank should be greater than or equal to 1");
template <typename T_, int Rank_> friend class strided_array_view;
template <typename T_, size_t Rank_> friend class strided_array_view;
pointer data_; // exposition only
bounds_type bnd_;
offset_type stride_;
Expand Down
7 changes: 7 additions & 0 deletions stl-test/Tests/array_view/array_view/array_view.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -28,6 +28,13 @@ int main()
for (int i = 0; i < 120; i++)
ret &= bv.data()[i] == i;
}
{
char a[12] {'H', 'i'};
auto av = std::array_view<char, 1>{a};
ret &= av.bounds() == std::bounds<1>{12};
ret &= av[{0}] == 'H';
ret &= av[{1}] == 'i';
}
{
std::vector<int> vec(120);
for (int i = 0; i < 120; i++)
Expand Down

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