#[repr(C)]
pub struct NSNumber { /* private fields */ }
Available on crate feature foundation only.
Expand description

An object wrapper for primitive scalars.

This is the Objective-C equivalant of a Rust enum containing the common scalar types i8, u8, i16, u16, i32, u32, i64, u64, f32, f64 and the two C types c_long and c_ulong.

All accessor methods are safe, though they may return unexpected results if the number was not created from said type. Consult Apple’s documentation for details.

Note that due to limitations in Objective-C type encodings, it is not possible to distinguish between an NSNumber created from bool, and one created from an i8/u8. You should use the getter methods that fit your use-case instead!

This does not implement Eq nor Ord, since it may contain a floating point value. Beware that the implementation of PartialEq and PartialOrd does not properly handle NaNs either. Compare NSNumber::encoding with Encoding::Float or Encoding::Double, and use NSNumber::as_f32 or NSNumber::as_f64 to get the desired floating point value directly.

See Apple’s documentation for more information.

Implementations

Creation methods.

Getter methods.

The Objective-C encoding of this NSNumber.

This is guaranteed to return one of:

Examples

Convert an NSNumber to/from an enumeration describing the different number properties.

use objc2::Encoding;
use objc2::foundation::NSNumber;
use objc2::rc::{Id, Shared};

// Note: `bool` would convert to either `Signed` or `Unsigned`,
// depending on platform
#[derive(Copy, Clone)]
pub enum Number {
    Signed(i64),
    Unsigned(u64),
    Floating(f64),
}

impl Number {
    fn into_nsnumber(self) -> Id<NSNumber, Shared> {
        match self {
            Self::Signed(val) => NSNumber::new_i64(val),
            Self::Unsigned(val) => NSNumber::new_u64(val),
            Self::Floating(val) => NSNumber::new_f64(val),
        }
    }
}

impl From<&NSNumber> for Number {
    fn from(n: &NSNumber) -> Self {
        match n.encoding() {
            Encoding::Char
            | Encoding::Short
            | Encoding::Int
            | Encoding::Long
            | Encoding::LongLong => Self::Signed(n.as_i64()),
            Encoding::UChar
            | Encoding::UShort
            | Encoding::UInt
            | Encoding::ULong
            | Encoding::ULongLong => Self::Unsigned(n.as_u64()),
            Encoding::Float
            | Encoding::Double => Self::Floating(n.as_f64()),
            _ => unreachable!(),
        }
    }
}

Methods from Deref<Target = NSValue>

Retrieve the data contained in the NSValue.

Note that this is broken on GNUStep for some types, see gnustep/libs-base#216.

Safety

The type of T must be what the NSValue actually stores, and any safety invariants that the value has must be upheld.

Note that it may be, but is not always, enough to simply check whether contains_encoding returns true. For example, NonNull<T> have the same encoding as *const T, but NonNull<T> is clearly not safe to return from this function even if you’ve checked the encoding beforehand.

Examples

Store a pointer in NSValue, and retrieve it again afterwards.

use std::ffi::c_void;
use std::ptr;
use objc2::foundation::NSValue;

let val = NSValue::new::<*const c_void>(ptr::null());
// SAFETY: The value was just created with a pointer
let res = unsafe { val.get::<*const c_void>() };
assert!(res.is_null());

Methods from Deref<Target = NSObject>

Check if the object is an instance of the class, or one of it’s subclasses.

See Apple’s documentation for more details on what you may (and what you may not) do with this information.

Methods from Deref<Target = Object>

Dynamically find the class of this object.

Returns a pointer to the instance variable / ivar with the given name.

This is similar to UnsafeCell::get, see that for more information on what is and isn’t safe to do.

Usually you will have defined the instance variable yourself with ClassBuilder::add_ivar, the type of the ivar T must match the type used in that.

Attempting to access or modify private implementation details of a class that you do no control using this is not supported, and may invoke undefined behaviour.

Library implementors are strongly encouraged to expose a safe interface to the ivar.

Panics

May panic if the object has no ivar with the given name. May also panic if the type encoding of the ivar differs from the type encoding of T.

This should purely seen as help while debugging and is not guaranteed (e.g. it may be disabled when debug_assertions are off).

Safety

The object must have an instance variable with the given name, and it must be of type T. Any invariants that the object have assumed about the value of the instance variable must not be violated.

No thread syncronization is done on accesses to the variable, so you must ensure that any access to the returned pointer do not cause data races, and that Rust’s mutability rules are not otherwise violated.

Returns a reference to the instance variable with the given name.

See Object::ivar_ptr for more information, including on when this panics.

Safety

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

No thread syncronization is done, so you must ensure that no other thread is concurrently mutating the variable. This requirement can be considered upheld if all mutation happens through Object::ivar_mut (since that takes &mut self).

👎Deprecated:

Use Object::ivar instead.

Use Object::ivar instead.

Safety

See Object::ivar.

Returns a mutable reference to the ivar with the given name.

See Object::ivar_ptr for more information, including on when this panics.

Safety

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

This access happens through &mut self, which means we know it to be the only reference, hence you do not need to do any work to ensure that data races do not happen.

👎Deprecated:

Use Object::ivar_mut instead.

Sets the value of the ivar with the given name.

This is just a helpful shorthand for Object::ivar_mut, see that for more information.

Safety

Same as Object::ivar_mut.

Trait Implementations

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

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

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

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

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

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

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

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

Immutably borrows from an owned value. Read more

Immutably borrows from an owned value. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

The superclass of this class. Read more

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

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

Get an immutable reference to the superclass.

Get a mutable reference to the superclass.

Formats the value using the given formatter. Read more

The resulting type after dereferencing.

Dereferences the value.

Mutably dereferences the value.

Formats the value using the given formatter. Read more

Feeds this value into the given Hasher. Read more

Feeds a slice of this type into the given Hasher. Read more

Available on crate feature foundation only.

Indicates whether the type is mutable or immutable. Read more

Available on crate feature foundation only.

The output type. Read more

Available on crate feature foundation only.

Beware: This uses the Objective-C method “isEqualToNumber:”, which has different floating point NaN semantics than Rust!

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason. Read more

Beware: This uses the Objective-C method “compare:”, which has different floating point NaN semantics than Rust!

This method returns an ordering between self and other values if one exists. Read more

This method tests less than (for self and other) and is used by the < operator. Read more

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more

This method tests greater than (for self and other) and is used by the > operator. Read more

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

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

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

Uses borrowed data to replace owned data, usually by cloning. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Converts the given value to a String. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.