Struct MPSNDArrayDescriptor 

pub struct MPSNDArrayDescriptor { /* private fields */ }

Available on crate feature MPSNDArray only.

Dependencies: This depends on Metal.framework

A MPSNDArrayDescriptor object describes a attributes of MPSNDArray and is used to create one (see MPSNDArray discussion below)

See also Apple’s documentation

Implementations

impl MPSNDArrayDescriptor

pub unsafe fn dataType(&self) -> MPSDataType

Available on crate features MPSCore and MPSCoreTypes only.

Data Type of the MPSNDArray elements

pub unsafe fn setDataType(&self, data_type: MPSDataType)

Available on crate features MPSCore and MPSCoreTypes only.

Setter for dataType.

pub unsafe fn numberOfDimensions(&self) -> NSUInteger

Available on crate feature MPSCore only.

The number of dimensions in the NDArray.

May not exceed 16. A 0-diumension MPSNDArray is a single scalar value. Undefined dimensions are implicitly length 1.

pub unsafe fn setNumberOfDimensions(&self, number_of_dimensions: NSUInteger)

Available on crate feature MPSCore only.

Setter for numberOfDimensions.

pub unsafe fn preferPackedRows(&self) -> bool

Available on crate feature MPSCore only.

If YES, then new NDArrays created with this descriptor will pack the rows. Default: NO.

pub unsafe fn setPreferPackedRows(&self, prefer_packed_rows: bool)

Available on crate feature MPSCore only.

Setter for preferPackedRows.

pub unsafe fn lengthOfDimension( &self, dimension_index: NSUInteger, ) -> NSUInteger

Available on crate feature MPSCore only.

The number of elements of type dataType in the indicated dimension.

If dimensionIndex >= numberOfDimensions, 1 will be returned.

Parameter dimensionIndex: dimension the MPSNDArray for which to return the length

Returns: The number of elements in that dimension.

pub unsafe fn sliceRangeForDimension( &self, dimension_index: NSUInteger, ) -> MPSDimensionSlice

Available on crate features MPSCore and MPSCoreTypes only.

The slice dimensions for each dimension

A slice is a subregion of a dimension. It is used to calve off a fraction of a larger NDArray.

Parameter dimensionIndex: The index of the dimension

Returns: Returns the slice range for the index. If the dimensionIndex >= numberOfDimensions, {0,1} is returned.

pub unsafe fn sliceDimension_withSubrange( &self, dimension_index: NSUInteger, sub_range: MPSDimensionSlice, )

Available on crate features MPSCore and MPSCoreTypes only.

The slice dimensions for each dimension

A slice is a subregion of a dimension. It is used to calve off a fraction of a larger NDArray.

Default: NSRange(0, lengthOfDimension(i))

Parameter subRange: The region of the slice, start value is wrt dimensionLength of the NDArray.

Parameter dimensionIndex: The index of the dimension. Must be < numberOfDimensions

pub unsafe fn transposeDimension_withDimension( &self, dimension_index: NSUInteger, dimension_index2: NSUInteger, )

Available on crate feature MPSCore only.

transpose two dimensions

If the intention is to insert a length 1 dimension, increment the numberOfDimensions first.

Parameter dimensionIndex: The first dimension. Must be < numberOfDimensions

Parameter dimensionIndex2: The second dimension. Must be < number of Dimensions.

pub unsafe fn permuteWithDimensionOrder( &self, dimension_order: NonNull<NSUInteger>, )

Available on crate feature MPSCore only.

Permutes the dimensions of the current descriptor

Parameter dimensionOrder: A permutation of the dimensions of the NDArray. dimensionOrder[i] must contain the new postion of dimenson i. Size of the array must be equal to the original number of dimensions in the descriptor. Must have all the indices in [0, numberOfDimensions) present uniquely.

This permutation is applied on top of whatever transpostions/permutations that may have been performed on the descriptor before.

Safety

dimension_order must be a valid pointer.

pub unsafe fn getShape(&self) -> Retained<NSArray<NSNumber>>

Available on crate feature MPSCore only.

Returns the shape of the NDArray as MPSShape

The length of the array is the number of dimensions and the size of the fastest running dimension is the last element in the array.

pub unsafe fn descriptorWithDataType_dimensionCount_dimensionSizes( data_type: MPSDataType, number_of_dimensions: NSUInteger, dimension_sizes: NonNull<NSUInteger>, ) -> Retained<Self>

Available on crate features MPSCore and MPSCoreTypes only.

Create an MPSNDArrayDescriptor object for a given size of dimensions.

Sample code:

                // Creates an NDArrayDescriptor of dimensions [32, 6, 5, 3]
                NSUInteger sizes[] = {3,5,6,32};
                [ MPSNDArray descriptorWithDataType: MPSDataTypeFloat32
                                     dimensionCount: 4
                                     dimensionSizes: sizes ];    // array of numberOfDimensions dimensions. Starts with dimension 0

Parameter dataType: MPSDataType of elements in the MPSNDArray

Parameter numberOfDimensions: Number of dimensions in the NDArray. May not exceed 16.

Parameter dimensionSizes: An array of NSUIntegers where dimension lengths provided by the user goes from fastest moving to slowest moving dimension. The product of all dimension lengths must be less than 2**31. Additional system memory limits may apply

Returns: A valid MPSNDArrayDescriptor object or nil, if failure.

Safety

dimension_sizes must be a valid pointer.

pub unsafe fn descriptorWithDataType_shape( data_type: MPSDataType, shape: &NSArray<NSNumber>, ) -> Retained<Self>

Available on crate features MPSCore and MPSCoreTypes only.

A convenience function to create an MPSNDArrayDescriptor object for a given size of dimensions.

Sample code:

                // Creates an NDArrayDescriptor of dimensions [32, 6, 5, 3]
                NSArray<NSNumber *> sizes = {@32,@6,@5,@3};
                [ MPSNDArray descriptorWithDataType: MPSDataTypeFloat32
                                              shape: &sizes];

Parameter dataType: MPSDataType of elements in the MPSNDArray

Parameter shape: An array of NSUIntegers where dimension lengths provided by the user goes from slowest moving to fastest moving dimension. This is same order as MLMultiArray in coreML and most frameworks in Python The product of all dimension lengths must be less than 2**31. Additional system memory limits may apply

Returns: A valid MPSNDArrayDescriptor object or nil, if failure.

pub unsafe fn reshapeWithDimensionCount_dimensionSizes( &self, number_of_dimensions: NSUInteger, dimension_sizes: NonNull<NSUInteger>, )

Available on crate feature MPSCore only.

Changes dimension sizes and number of dimensions on the current descriptor

Parameter numberOfDimensions: Number of dimensions in the NDArray. May not exceed 16.

Parameter dimensionSizes: An array of NSUIntegers where dimension lengths provided by the user goes from fastest moving to slowest moving dimension. The product of all dimension lengths must be less than 2**31. Additional system memory limits may apply

Safety

dimension_sizes must be a valid pointer.

pub unsafe fn reshapeWithShape(&self, shape: &NSArray<NSNumber>)

Available on crate feature MPSCore only.

Changes dimension sizes and number of dimensions on the current descriptor

Parameter shape: An array of NSUIntegers where dimension lengths provided by the user goes from slowest moving to fastest moving dimension. This is same order as MLMultiArray in coreML and most frameworks in Python The product of all dimension lengths must be less than 2**31. Additional system memory limits may apply

pub unsafe fn init(this: Allocated<Self>) -> Retained<Self>

Available on crate feature MPSCore only.

Use -descriptorWithDataType:… instead

impl MPSNDArrayDescriptor

Methods declared on superclass NSObject.

pub unsafe fn new() -> Retained<Self>

Available on crate feature MPSCore only.

Methods from Deref<Target = NSObject>

pub fn doesNotRecognizeSelector(&self, sel: Sel) -> !

Handle messages the object doesn’t recognize.

See Apple’s documentation for details.

Methods from Deref<Target = AnyObject>

pub fn class(&self) -> &'static AnyClass

Dynamically find the class of this object.

Panics

May panic if the object is invalid (which may be the case for objects returned from unavailable init/new methods).

Example

Check that an instance of NSObject has the precise class NSObject.

use objc2::ClassType;
use objc2::runtime::NSObject;

let obj = NSObject::new();
assert_eq!(obj.class(), NSObject::class());

pub unsafe fn get_ivar<T>(&self, name: &str) -> &T

where T: Encode,

👎Deprecated: this is difficult to use correctly, use Ivar::load instead.

Use Ivar::load instead.

Safety

The object must have an instance variable with the given name, and it must be of type T.

See Ivar::load_ptr for details surrounding this.

pub fn downcast_ref<T>(&self) -> Option<&T>

where T: DowncastTarget,

Attempt to downcast the object to a class of type T.

This is the reference-variant. Use Retained::downcast if you want to convert a retained object to another type.

Mutable classes

Some classes have immutable and mutable variants, such as NSString and NSMutableString.

When some Objective-C API signature says it gives you an immutable class, it generally expects you to not mutate that, even though it may technically be mutable “under the hood”.

So using this method to convert a NSString to a NSMutableString, while not unsound, is generally frowned upon unless you created the string yourself, or the API explicitly documents the string to be mutable.

See Apple’s documentation on mutability and on isKindOfClass: for more details.

Generic classes

Objective-C generics are called “lightweight generics”, and that’s because they aren’t exposed in the runtime. This makes it impossible to safely downcast to generic collections, so this is disallowed by this method.

You can, however, safely downcast to generic collections where all the type-parameters are AnyObject.

Panics

This works internally by calling isKindOfClass:. That means that the object must have the instance method of that name, and an exception will be thrown (if CoreFoundation is linked) or the process will abort if that is not the case. In the vast majority of cases, you don’t need to worry about this, since both root objects NSObject and NSProxy implement this method.

Examples

Cast an NSString back and forth from NSObject.

use objc2::rc::Retained;
use objc2_foundation::{NSObject, NSString};

let obj: Retained<NSObject> = NSString::new().into_super();
let string = obj.downcast_ref::<NSString>().unwrap();
// Or with `downcast`, if we do not need the object afterwards
let string = obj.downcast::<NSString>().unwrap();

Try (and fail) to cast an NSObject to an NSString.

use objc2_foundation::{NSObject, NSString};

let obj = NSObject::new();
assert!(obj.downcast_ref::<NSString>().is_none());

Try to cast to an array of strings.

use objc2_foundation::{NSArray, NSObject, NSString};

let arr = NSArray::from_retained_slice(&[NSObject::new()]);
// This is invalid and doesn't type check.
let arr = arr.downcast_ref::<NSArray<NSString>>();

This fails to compile, since it would require enumerating over the array to ensure that each element is of the desired type, which is a performance pitfall.

Downcast when processing each element instead.

use objc2_foundation::{NSArray, NSObject, NSString};

let arr = NSArray::from_retained_slice(&[NSObject::new()]);

for elem in arr {
    if let Some(data) = elem.downcast_ref::<NSString>() {
        // handle `data`
    }
}

Trait Implementations

impl AsRef<AnyObject> for MPSNDArrayDescriptor

Available on crate feature MPSCore only.

fn as_ref(&self) -> &AnyObject

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<MPSNDArrayDescriptor> for MPSNDArrayDescriptor

Available on crate feature MPSCore only.

fn as_ref(&self) -> &Self

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<NSObject> for MPSNDArrayDescriptor

Available on crate feature MPSCore only.

fn as_ref(&self) -> &NSObject

Converts this type into a shared reference of the (usually inferred) input type.

impl Borrow<AnyObject> for MPSNDArrayDescriptor

Available on crate feature MPSCore only.

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<NSObject> for MPSNDArrayDescriptor

Available on crate feature MPSCore only.

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for MPSNDArrayDescriptor

Available on crate feature MPSCore only.

const NAME: &'static str = "MPSNDArrayDescriptor"

The name of the Objective-C class that this type represents.

type Super = NSObject

The superclass of this class.

type ThreadKind = <<MPSNDArrayDescriptor as ClassType>::Super as ClassType>::ThreadKind

Whether the type can be used from any thread, or from only the main thread.

fn class() -> &'static AnyClass

Get a reference to the Objective-C class that this type represents.

fn as_super(&self) -> &Self::Super

Get an immutable reference to the superclass.

impl Debug for MPSNDArrayDescriptor

Available on crate feature MPSCore only.

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Deref for MPSNDArrayDescriptor

Available on crate feature MPSCore only.

type Target = NSObject

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl Hash for MPSNDArrayDescriptor

Available on crate feature MPSCore only.

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Message for MPSNDArrayDescriptor

Available on crate feature MPSCore only.

fn retain(&self) -> Retained<Self>

where Self: Sized,

Increment the reference count of the receiver.

impl NSObjectProtocol for MPSNDArrayDescriptor

Available on crate feature MPSCore only.

fn isEqual(&self, other: Option<&AnyObject>) -> bool

where Self: Sized + Message,

Check whether the object is equal to an arbitrary other object.

fn hash(&self) -> usize

where Self: Sized + Message,

An integer that can be used as a table address in a hash table structure.

fn isKindOfClass(&self, cls: &AnyClass) -> bool

where Self: Sized + Message,

Check if the object is an instance of the class, or one of its subclasses.

fn is_kind_of<T>(&self) -> bool

where T: ClassType, Self: Sized + Message,

👎Deprecated: use isKindOfClass directly, or cast your objects with AnyObject::downcast_ref

Check if the object is an instance of the class type, or one of its subclasses.

fn isMemberOfClass(&self, cls: &AnyClass) -> bool

where Self: Sized + Message,

Check if the object is an instance of a specific class, without checking subclasses.

fn respondsToSelector(&self, aSelector: Sel) -> bool

where Self: Sized + Message,

Check whether the object implements or inherits a method with the given selector.

fn conformsToProtocol(&self, aProtocol: &AnyProtocol) -> bool

where Self: Sized + Message,

Check whether the object conforms to a given protocol.

fn description(&self) -> Retained<NSObject>

where Self: Sized + Message,

A textual representation of the object.

fn debugDescription(&self) -> Retained<NSObject>

where Self: Sized + Message,

A textual representation of the object to use when debugging.

fn isProxy(&self) -> bool

where Self: Sized + Message,

Check whether the receiver is a subclass of the NSProxy root class instead of the usual NSObject.

fn retainCount(&self) -> usize

where Self: Sized + Message,

The reference count of the object.

impl PartialEq for MPSNDArrayDescriptor

Available on crate feature MPSCore only.

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl RefEncode for MPSNDArrayDescriptor

Available on crate feature MPSCore only.

const ENCODING_REF: Encoding = <NSObject as ::objc2::RefEncode>::ENCODING_REF

The Objective-C type-encoding for a reference of this type.

impl DowncastTarget for MPSNDArrayDescriptor

Available on crate feature MPSCore only.

impl Eq for MPSNDArrayDescriptor

Available on crate feature MPSCore only.