pub struct UserDataMap { /* fields omitted */ }
A storage able to store several values of UserData
of different types. It behaves similarly to a TypeMap
.
Attempt to access the wrapped user data of a given type
Will return None
if no value of type T
is stored in this UserDataMap
and accessible from this thread
Insert a value in the map if it is not already there
This is the non-threadsafe variant, the type you insert don't have to be
threadsafe, but they will not be visible from other threads (even if they are
actually threadsafe).
If the value does not already exists, the closure is called to create it and
this function returns true
. If the value already exists, the closure is not
called, and this function returns false
.
Insert a value in the map if it is not already there
This is the threadsafe variant, the type you insert must be threadsafe and will
be visible from all threads.
If the value does not already exists, the closure is called to create it and
this function returns true
. If the value already exists, the closure is not
called, and this function returns false
.
🔬 This is a nightly-only experimental API. (try_from
)
The type returned in the event of a conversion error.
🔬 This is a nightly-only experimental API. (try_from
)
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more
🔬 This is a nightly-only experimental API. (try_from
)
The type returned in the event of a conversion error.
🔬 This is a nightly-only experimental API. (try_from
)
🔬 This is a nightly-only experimental API. (get_type_id
)
this method will likely be replaced by an associated static
Convert Box<Trait>
(where Trait: Downcast
) to Box<Any>
. Box<Any>
can then be further downcast
into Box<ConcreteType>
where ConcreteType
implements Trait
. Read more
Convert &Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot generate &Any
's vtable from &Trait
's. Read more
Convert &mut Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot generate &mut Any
's vtable from &mut Trait
's. Read more