Struct Map

pub struct Map<A: ?Sized + Downcast = dyn Any> { /* private fields */ }

A collection containing zero or one values for any given type and allowing convenient, type-safe access to those values.

The type parameter A allows you to use a different value type; normally you will want it to be core::any::Any (also known as std::any::Any), but there are other choices:

• You can add on + Send or + Send + Sync (e.g. Map<dyn Any + Send>) to add those auto traits.

Cumulatively, there are thus six forms of map:

• Map<dyn core::any::Any>, also spelled AnyMap for convenience.
• Map<dyn core::any::Any + Send>
• Map<dyn core::any::Any + Send + Sync>

Example

(Here using the AnyMap convenience alias; the first line could use anymap::Map::<core::any::Any>::new() instead if desired.)

let mut data = anymap::AnyMap::new();
assert_eq!(data.get(), None::<&i32>);

Values containing non-static references are not permitted.

Implementations

impl<A: ?Sized + Downcast> Map<A>

pub fn new() -> Map<A>

Create an empty collection.

pub fn get<T: IntoBox<A>>(&self) -> Option<&T>

Returns a reference to the value stored in the collection for the type T, if it exists.

pub fn entry<T: IntoBox<A>>(&mut self) -> Entry<'_, A, T>

Gets the entry for the given type in the collection for in-place manipulation

Trait Implementations

impl<A: Debug + ?Sized + Downcast> Debug for Map<A>

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

Formats the value using the given formatter.

impl<A: ?Sized + Downcast> Default for Map<A>

fn default() -> Map<A>

Returns the “default value” for a type.