Struct GKGaussianDistribution 

pub struct GKGaussianDistribution { /* private fields */ }

Available on crate feature GKRandomDistribution only.

A gaussian distribution is biased towards the mean value, the possible outcomes are spread out from the mean with decreasing probability. Values within 1 deviation of the mean make up 68.27% of the distribution, values within 2 deviations make up 95% and values within 3 deviations make up 99.7%.

Note that a gaussian distribution’s unbounded behavior beyond 3 deviations is undesired, thus this distribution deviates nominally by modifying the bounds to 3 deviations. Thus values within 3 deviations actually make up 100% of the distribution.

See also Apple’s documentation

Implementations

impl GKGaussianDistribution

pub unsafe fn mean(&self) -> c_float

The mean, or expected, value of the distribution. Values are more probable the closer to the mean they are.

pub unsafe fn deviation(&self) -> c_float

The deviation, often called ‘sigma’, is the deviation from the mean that would include roughly 68% of the distribution. The range of the distribution is [mean - 3 * deviation, mean + 3 * deviation]. Values beyond 3 deviations are considered so improbable that they are removed from the output set.

pub unsafe fn initWithRandomSource_lowestValue_highestValue( this: Allocated<Self>, source: &ProtocolObject<dyn GKRandom>, lowest_inclusive: NSInteger, highest_inclusive: NSInteger, ) -> Retained<Self>

Available on crate feature GKRandomSource only.

Initializes a Gaussian random distribution within the range [lowest, highest] using a source to grab input values from. This sets the gaussian parameters to:

mean = (highest + lowest) / 2 deviation = (highest - lowest) / 6

The mean and deviation will be floating point numbers even if the distribution is meant to produce integer values.

See: mean

See: deviation

pub unsafe fn initWithRandomSource_mean_deviation( this: Allocated<Self>, source: &ProtocolObject<dyn GKRandom>, mean: c_float, deviation: c_float, ) -> Retained<Self>

Available on crate feature GKRandomSource only.

Initializes a Gaussian random distribution within the range [mean - 3 * deviation, mean + 3 * deviation] using a source to grab input values from.

impl GKGaussianDistribution

Methods declared on superclass GKRandomDistribution.

pub unsafe fn distributionWithLowestValue_highestValue( lowest_inclusive: NSInteger, highest_inclusive: NSInteger, ) -> Retained<Self>

Convenience creation of random distribution within the range [lowest, highest] using an isolated source to grab input values from. This is equivalent to calling alloc followed by initWithSource:lowest:highest:, where source is [[GKRandomSource alloc] init].

See: initWithRandomSource:lowestValue:highestValue:

pub unsafe fn distributionForDieWithSideCount( side_count: NSInteger, ) -> Retained<Self>

Convenience creation of random distribution with the die like range [1, sideCount] using an isolated source to grab input values from. This is equivalent to calling alloc followed by initWithSource:lowest:highest:, where source is [[GKRandomSource alloc] init].

See: initWithRandomSource:lowestValue:highestValue:

pub unsafe fn d6() -> Retained<Self>

Convenience creation for the very common d6 range [1, 6] with an isolated random source shielded from outside sources.

pub unsafe fn d20() -> Retained<Self>

Convenience creation for the very common d20 range [1, 20] with an isolated random source shielded from outside sources.

impl GKGaussianDistribution

Methods declared on superclass NSObject.

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

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

Methods from Deref<Target = GKRandomDistribution>

pub unsafe fn lowestValue(&self) -> NSInteger

The lowest value the distribution will output.

pub unsafe fn highestValue(&self) -> NSInteger

The highest value the distribution will output.

pub unsafe fn numberOfPossibleOutcomes(&self) -> NSUInteger

The number of unique possible outcomes, depending on the distribution type this is not always highest - lowest + 1.

pub unsafe fn nextInt(&self) -> NSInteger

Returns the next integer in the distribution sequence and moves ahead to the next one. The value is in the range of [lowest, highest].

pub unsafe fn nextIntWithUpperBound( &self, upper_bound: NSUInteger, ) -> NSUInteger

Returns the next unsigned value in the distribution sequence that is less than upperBound. The value never equals or exceeeds upperBounds, and in this case it will also never exceed the highest value of the distribution.

pub unsafe fn nextUniform(&self) -> c_float

Returns the next uniform float in the random sequence and moves ahead to the next one. The value is in the range of [lowest / higest, 1.0].

The value is quantized to the distribution’s lowest and highest bounds. Thus on a d20 distribution the value is quantized to 5% increments. The output value 0 is not possible to get unless the lowest value bound is also 0 or below.

See: nextInt

pub unsafe fn nextBool(&self) -> bool

Returns the next true or false value in the distribution sequence and moves ahead to the next one. The value is either nonzero (true) or zero (false). Use this for simple boolean switches in logic that don’t require fuzzy evaluation. For fuzzy evaluation use nextUniform.

By default this is based on the referenced source’s definition of nextBool.

See: GKRandomSource.nextBool

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 GKGaussianDistribution

fn as_ref(&self) -> &AnyObject

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

impl AsRef<GKGaussianDistribution> for GKGaussianDistribution

fn as_ref(&self) -> &Self

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

impl AsRef<GKRandomDistribution> for GKGaussianDistribution

fn as_ref(&self) -> &GKRandomDistribution

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

impl AsRef<NSObject> for GKGaussianDistribution

fn as_ref(&self) -> &NSObject

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

impl Borrow<AnyObject> for GKGaussianDistribution

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<GKRandomDistribution> for GKGaussianDistribution

fn borrow(&self) -> &GKRandomDistribution

Immutably borrows from an owned value.

impl Borrow<NSObject> for GKGaussianDistribution

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for GKGaussianDistribution

const NAME: &'static str = "GKGaussianDistribution"

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

type Super = GKRandomDistribution

The superclass of this class.

type ThreadKind = <<GKGaussianDistribution 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 GKGaussianDistribution

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

Formats the value using the given formatter.

impl Deref for GKGaussianDistribution

type Target = GKRandomDistribution

The resulting type after dereferencing.

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

Dereferences the value.

impl GKRandom for GKGaussianDistribution

unsafe fn nextInt(&self) -> NSInteger

where Self: Sized + Message,

Available on crate feature GKRandomSource only.

Returns the next integer in the random sequence and moves ahead to the next one. The value is in the range of [INT32_MIN, INT32_MAX]. The lower bits are not guaranteed to be random so please use another property for simple choices.

unsafe fn nextIntWithUpperBound(&self, upper_bound: NSUInteger) -> NSUInteger

where Self: Sized + Message,

Available on crate feature GKRandomSource only.

Returns the next unsigned value in the random sequence that is less than upperBound. The value is in the range of [0, upperBound). Thus the value never equals or exceeeds upperBound. The unsigned nature and upper bound allows implementations to use logical shifts to return a value whose lower bits are more random than a similar call to nextInt.

unsafe fn nextUniform(&self) -> c_float

where Self: Sized + Message,

Available on crate feature GKRandomSource only.

Returns the next uniform float in the random sequence and moves ahead to the next one. The value is in the range of [0.0, 1.0]. There is no weighting across the range so remapping this with a curve may give the best sampling distribution for your algorithm.

unsafe fn nextBool(&self) -> bool

where Self: Sized + Message,

Available on crate feature GKRandomSource only.

Returns the next true or false value in the random sequence and moves ahead to the next one. The value is either nonzero (true) or zero (false). Use this for simple boolean switches in logic that don’t require fuzzy evaluation. For fuzzy evaluation use nextUniform.

impl Hash for GKGaussianDistribution

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 GKGaussianDistribution

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

where Self: Sized,

Increment the reference count of the receiver.

impl NSObjectProtocol for GKGaussianDistribution

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 GKGaussianDistribution

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 GKGaussianDistribution

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

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

impl DowncastTarget for GKGaussianDistribution

impl Eq for GKGaussianDistribution