sycl::item#
template <int Dimensions = 1, bool WithOffset = true>
class item;
Template parameters
|
Number of dimensions in the index space. |
|
|
sycl::item identifies an instance of the function object
executing at each point in a sycl::range. It is passed to a
parallel_for call or returned by member functions of sycl::h_item.
It encapsulates enough information to identify the work-item's range of possible values and its sycl::id in that range.
Note
It can optionally carry the offset of the range if provided to the parallel_for.
This is deprecated in SYCL 2020.
Instances of the sycl::item class are not user-constructible
and are passed by the runtime to each instance of the function object.
So the interface of the sycl::item does not expose a constructor.
The sycl::item class template provides the Common By-value Semantics.
See also
SYCL Specification Section 4.9.1.4
Member functions#
get_id#
Overload 1
sycl::id<Dimensions> get_id() const;
Return the constituent sycl::id representing the work-item's position in the iteration space.
Overload 2
size_t get_id(int dimension) const;
Return the same value as get_id()[dimension].
get_range#
Overload 1
sycl::range<Dimensions> get_range() const;
Returns a sycl::range representing the dimensions of
the range of possible values of the sycl::item.
Overload 2
size_t get_range(int dimension) const;
Return the same value as get_range().get(dimension).
get_offset#
sycl::id<Dimensions> get_offset() const;
Note
Deprecated in SYCL 2020.
Returns an sycl::id representing the n-dimensional offset
provided to the parallel_for and that is added by the
runtime to the global-ID of each work-item, if this item
represents a global range.
For an item converted from an item with no offset this will always return an sycl::id of all 0 values.
This member function is only available if
WithOffset is true.
get_linear_id#
size_t get_linear_id() const;
Return the id as a linear index value.
Calculating a linear address from the multi-dimensional index follows SYCL Specification Section 3.11.1.
operator[]#
size_t operator[](int dimension) const;
Return the same value as get_id(dimension).
Type conversion functions#
operator size_t#
operator size_t() const;
Available only when: Dimensions == 1.
Returns the same value as get_id(0).
operator item#
operator item<Dimensions, true>() const;
Available only when: WithOffset == false.
Returns a sycl::item representing the same information as
the object holds but also includes the offset set to 0.
This conversion allow users to seamlessly write code that
assumes an offset and still provides an offset-less sycl::item.