Struct MPSNNNeuronDescriptor 

pub struct MPSNNNeuronDescriptor { /* private fields */ }

Available on crate feature MPSCNNNeuron only.

Dependencies: This depends on Metal.framework

The MPSNNNeuronDescriptor specifies a neuron descriptor. Supported neuron types:

Neuron type “none”: f(x) = x Parameters: none

ReLU neuron filter: f(x) = x >= 0 ? x : a * x This is called Leaky ReLU in literature. Some literature defines classical ReLU as max(0, x). If you want this behavior, simply pass a = 0. Parameters: a For default behavior, set the value of a to 0.0f.

Linear neuron filter: f(x) = a * x + b Parameters: a, b For default behavior, set the value of a to 1.0f and the value of b to 0.0f.

Sigmoid neuron filter: f(x) = 1 / (1 + e^-x) Parameters: none

Hard Sigmoid filter: f(x) = clamp((x * a) + b, 0, 1) Parameters: a, b For default behavior, set the value of a to 0.2f and the value of b to 0.5f.

Hyperbolic tangent (TanH) neuron filter: f(x) = a * tanh(b * x) Parameters: a, b For default behavior, set the value of a to 1.0f and the value of b to 1.0f.

Absolute neuron filter: f(x) = fabs(x) Parameters: none

Parametric Soft Plus neuron filter: f(x) = a * log(1 + e^(b * x)) Parameters: a, b For default behavior, set the value of a to 1.0f and the value of b to 1.0f.

Parametric Soft Sign neuron filter: f(x) = x / (1 + abs(x)) Parameters: none

Parametric ELU neuron filter: f(x) = x >= 0 ? x : a * (exp(x) - 1) Parameters: a For default behavior, set the value of a to 1.0f.

Parametric ReLU (PReLU) neuron filter: Same as ReLU, except parameter aArray is per channel. For each pixel, applies the following function: f(x_i) = x_i, if x_i >= 0 = a_i * x_i if x_i < 0 i in [0…channels-1] i.e. parameters a_i are learned and applied to each channel separately. Compare this to ReLu where parameter a is shared across all channels. See https://arxiv.org/pdf/1502.01852.pdf for details. Parameters: aArray - Array of floats containing per channel value of PReLu parameter count - Number of float values in array aArray.

ReLUN neuron filter: f(x) = min((x >= 0 ? x : a * x), b) Parameters: a, b As an example, the TensorFlow Relu6 activation layer can be implemented by setting the parameter b to 6.0f: https://www.tensorflow.org/api_docs/cc/class/tensorflow/ops/relu6. For default behavior, set the value of a to 1.0f and the value of b to 6.0f.

See also Apple’s documentation

Implementations

impl MPSNNNeuronDescriptor

pub unsafe fn neuronType(&self) -> MPSCNNNeuronType

Available on crate features MPSNeuralNetwork and MPSCNNNeuronType only.

pub unsafe fn setNeuronType(&self, neuron_type: MPSCNNNeuronType)

Available on crate features MPSNeuralNetwork and MPSCNNNeuronType only.

Setter for neuronType.

pub unsafe fn a(&self) -> c_float

Available on crate feature MPSNeuralNetwork only.

pub unsafe fn setA(&self, a: c_float)

Available on crate feature MPSNeuralNetwork only.

Setter for a.

pub unsafe fn b(&self) -> c_float

Available on crate feature MPSNeuralNetwork only.

pub unsafe fn setB(&self, b: c_float)

Available on crate feature MPSNeuralNetwork only.

Setter for b.

pub unsafe fn c(&self) -> c_float

Available on crate feature MPSNeuralNetwork only.

pub unsafe fn setC(&self, c: c_float)

Available on crate feature MPSNeuralNetwork only.

Setter for c.

pub unsafe fn data(&self) -> Option<Retained<NSData>>

Available on crate feature MPSNeuralNetwork only.

pub unsafe fn setData(&self, data: Option<&NSData>)

Available on crate feature MPSNeuralNetwork only.

Setter for data.

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

Available on crate feature MPSNeuralNetwork only.

You must use one of the interfaces below instead.

pub unsafe fn cnnNeuronDescriptorWithType( neuron_type: MPSCNNNeuronType, ) -> Retained<MPSNNNeuronDescriptor>

Available on crate features MPSNeuralNetwork and MPSCNNNeuronType only.

Make a descriptor for a MPSCNNNeuron object.

Parameter neuronType: The type of a neuron filter.

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

pub unsafe fn cnnNeuronDescriptorWithType_a( neuron_type: MPSCNNNeuronType, a: c_float, ) -> Retained<MPSNNNeuronDescriptor>

Available on crate features MPSNeuralNetwork and MPSCNNNeuronType only.

Make a descriptor for a MPSCNNNeuron object.

Parameter neuronType: The type of a neuron filter.

Parameter a: Parameter “a”.

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

pub unsafe fn cnnNeuronDescriptorWithType_a_b( neuron_type: MPSCNNNeuronType, a: c_float, b: c_float, ) -> Retained<MPSNNNeuronDescriptor>

Available on crate features MPSNeuralNetwork and MPSCNNNeuronType only.

Initialize the neuron descriptor.

Parameter neuronType: The type of a neuron filter.

Parameter a: Parameter “a”.

Parameter b: Parameter “b”.

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

pub unsafe fn cnnNeuronDescriptorWithType_a_b_c( neuron_type: MPSCNNNeuronType, a: c_float, b: c_float, c: c_float, ) -> Retained<MPSNNNeuronDescriptor>

Available on crate features MPSNeuralNetwork and MPSCNNNeuronType only.

Make a descriptor for a MPSCNNNeuron object.

Parameter neuronType: The type of a neuron filter.

Parameter a: Parameter “a”.

Parameter b: Parameter “b”.

Parameter c: Parameter “c”.

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

pub unsafe fn cnnNeuronPReLUDescriptorWithData_noCopy( data: &NSData, no_copy: bool, ) -> Retained<MPSNNNeuronDescriptor>

Available on crate feature MPSNeuralNetwork only.

Make a descriptor for a neuron of type MPSCNNNeuronTypePReLU.

The PReLU neuron is the same as a ReLU neuron, except parameter “a” is per feature channel.

Parameter data: A NSData containing a float array with the per feature channel value of PReLu parameter. The number of float values in this array usually corresponds to number of output channels in a convolution layer. The descriptor retains the NSData object.

Parameter noCopy: An optimization flag that tells us whether the NSData allocation is suitable for use directly with no copying of the data into internal storage. This allocation has to match the same restrictions as listed for the newBufferWithBytesNoCopy:length:options:deallocator: method of MTLBuffer.

Returns: A valid MPSNNNeuronDescriptor object for a neuron of type MPSCNNNeuronTypePReLU or nil, if failure

impl MPSNNNeuronDescriptor

Methods declared on superclass NSObject.

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

Available on crate feature MPSNeuralNetwork 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 MPSNNNeuronDescriptor

Available on crate feature MPSNeuralNetwork only.

fn as_ref(&self) -> &AnyObject

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

impl AsRef<MPSNNNeuronDescriptor> for MPSNNNeuronDescriptor

Available on crate feature MPSNeuralNetwork only.

fn as_ref(&self) -> &Self

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

impl AsRef<NSObject> for MPSNNNeuronDescriptor

Available on crate feature MPSNeuralNetwork only.

fn as_ref(&self) -> &NSObject

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

impl Borrow<AnyObject> for MPSNNNeuronDescriptor

Available on crate feature MPSNeuralNetwork only.

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<NSObject> for MPSNNNeuronDescriptor

Available on crate feature MPSNeuralNetwork only.

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for MPSNNNeuronDescriptor

Available on crate feature MPSNeuralNetwork only.

const NAME: &'static str = "MPSNNNeuronDescriptor"

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

type Super = NSObject

The superclass of this class.

type ThreadKind = <<MPSNNNeuronDescriptor 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 CopyingHelper for MPSNNNeuronDescriptor

Available on crate feature MPSNeuralNetwork only.

type Result = MPSNNNeuronDescriptor

The immutable counterpart of the type, or Self if the type has no immutable counterpart.

impl Debug for MPSNNNeuronDescriptor

Available on crate feature MPSNeuralNetwork only.

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

Formats the value using the given formatter.

impl Deref for MPSNNNeuronDescriptor

Available on crate feature MPSNeuralNetwork only.

type Target = NSObject

The resulting type after dereferencing.

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

Dereferences the value.

impl Hash for MPSNNNeuronDescriptor

Available on crate feature MPSNeuralNetwork 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 MPSNNNeuronDescriptor

Available on crate feature MPSNeuralNetwork only.

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

where Self: Sized,

Increment the reference count of the receiver.

impl NSCoding for MPSNNNeuronDescriptor

Available on crate feature MPSNeuralNetwork only.

unsafe fn encodeWithCoder(&self, coder: &NSCoder)

where Self: Sized + Message,

Safety

unsafe fn initWithCoder( this: Allocated<Self>, coder: &NSCoder, ) -> Option<Retained<Self>>

where Self: Sized + Message,

Safety

impl NSCopying for MPSNNNeuronDescriptor

Available on crate feature MPSNeuralNetwork only.

fn copy(&self) -> Retained<Self::Result>

where Self: Sized + Message + CopyingHelper,

Returns a new instance that’s a copy of the receiver.

unsafe fn copyWithZone(&self, zone: *mut NSZone) -> Retained<Self::Result>

where Self: Sized + Message + CopyingHelper,

Returns a new instance that’s a copy of the receiver.

impl NSObjectProtocol for MPSNNNeuronDescriptor

Available on crate feature MPSNeuralNetwork 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 NSSecureCoding for MPSNNNeuronDescriptor

Available on crate feature MPSNeuralNetwork only.

fn supportsSecureCoding() -> bool

where Self: Sized + ClassType,

impl PartialEq for MPSNNNeuronDescriptor

Available on crate feature MPSNeuralNetwork 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 MPSNNNeuronDescriptor

Available on crate feature MPSNeuralNetwork 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 MPSNNNeuronDescriptor

Available on crate feature MPSNeuralNetwork only.

impl Eq for MPSNNNeuronDescriptor

Available on crate feature MPSNeuralNetwork only.