Struct Dynamic

pub struct Dynamic { /* private fields */ }

A dynamically typed value.

Differs from Any in that it pre-computes type information at creation-time, so that downcasting and other queries to the type information can be implemented without virtual calls.

Not Sized, since the size of the type is determined at runtime, so must be used behind a pointer (e.g. &Dynamic, Box<Dynamic>, etc.)

Implementations

impl Dynamic

pub fn new<T: Any>(val: T) -> Box<Dynamic>

Create a new, heap-allocated Dynamic value containing the given value.

The resulting Dynamic can be downcasted back to a T.

pub fn from_ref<T: Any>(val: &Described<T>) -> &Dynamic

Create a new, immutable Dynamic value from the given described reference.

The resulting Dynamic can be downcasted back to a T.

pub fn from_mut<T: Any>(val: &mut Described<T>) -> &mut Dynamic

Create a new, mutable Dynamic value from the given described reference.

The resulting Dynamic can be downcasted back to a T.

pub fn id(&self) -> TypeId

Read the type id for the contained value.

pub fn is<T: Any>(&self) -> bool

Check if the contained type is a T.

pub fn downcast<T: Any>(self: Box<Self>) -> Result<Box<Described<T>>, Box<Self>>

If the contained value is a T, downcast back to it.

If the value is not a T, returns Err(self).

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

If the contained value is a T, get an immutable reference to it.

pub fn downcast_mut<T: Any>(&mut self) -> Option<&mut T>

If the contained value is a T, get a mutable reference to it.

Trait Implementations

impl Debug for Dynamic

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

Formats the value using the given formatter.