Struct anymap::Map

source ·

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

Expand description

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 anymap::any::Any, but there are other choices:

If you want the entire map to be cloneable, use CloneAny instead of Any.
You can add on + Send and/or + Sync (e.g. Map<Any + Send>) to add those bounds.

let mut data = AnyMap::new();
assert_eq!(data.get(), None::<&i32>);
data.insert(42i32);
assert_eq!(data.get(), Some(&42i32));
data.remove::<i32>();
assert_eq!(data.get::<i32>(), None);

#[derive(Clone, PartialEq, Debug)]
struct Foo {
    str: String,
}

assert_eq!(data.get::<Foo>(), None);
data.insert(Foo { str: format!("foo") });
assert_eq!(data.get(), Some(&Foo { str: format!("foo") }));
data.get_mut::<Foo>().map(|foo| foo.str.push('t'));
assert_eq!(&*data.get::<Foo>().unwrap().str, "foot");

Values containing non-static references are not permitted.

Implementations§

source §

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

source

pub fn new() -> Map<A>

Create an empty collection.

source

pub fn with_capacity(capacity: usize) -> Map<A>

Creates an empty collection with the given initial capacity.

source

pub fn capacity(&self) -> usize

Returns the number of elements the collection can hold without reallocating.

source

pub fn reserve(&mut self, additional: usize)

Reserves capacity for at least additional more elements to be inserted in the collection. The collection may reserve more space to avoid frequent reallocations.

Panics

Panics if the new allocation size overflows usize.

source

pub fn shrink_to_fit(&mut self)

Shrinks the capacity of the collection as much as possible. It will drop down as much as possible while maintaining the internal rules and possibly leaving some space in accordance with the resize policy.

source

pub fn len(&self) -> usize

Returns the number of items in the collection.

source

pub fn is_empty(&self) -> bool

Returns true if there are no items in the collection.

source

pub fn clear(&mut self)

Removes all items from the collection. Keeps the allocated memory for reuse.

source §

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

source

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.

source

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

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

source

pub fn insert<T: IntoBox<A>>(&mut self, value: T) -> Option<T>

Sets the value stored in the collection for the type T. If the collection already had a value of type T, that value is returned. Otherwise, None is returned.

source