Struct AnyUserData

pub struct AnyUserData<'lua>(/* private fields */);

Handle to an internal Lua userdata for any type that implements UserData.

Similar to std::any::Any, this provides an interface for dynamic type checking via the is and borrow methods.

Internally, instances are stored in a RefCell, to best match the mutable semantics of the Lua language.

Note

This API should only be used when necessary. Implementing UserData already allows defining methods which check the type and acquire a borrow behind the scenes.

Implementations

impl<'lua> AnyUserData<'lua>

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

where T: 'static + UserData,

Checks whether the type of this userdata is T.

pub fn borrow<T>(&self) -> Result<Ref<'_, T>, Error>

where T: 'static + UserData,

Borrow this userdata immutably if it is of type T.

Errors

Returns a UserDataBorrowError if the userdata is already mutably borrowed. Returns a UserDataTypeMismatch if the userdata is not of type T.

pub fn borrow_mut<T>(&self) -> Result<RefMut<'_, T>, Error>

where T: 'static + UserData,

Borrow this userdata mutably if it is of type T.

Errors

Returns a UserDataBorrowMutError if the userdata is already borrowed. Returns a UserDataTypeMismatch if the userdata is not of type T.

pub fn set_user_value<V>(&self, v: V) -> Result<(), Error>

where V: ToLua<'lua>,

Sets an associated value to this AnyUserData.

The value may be any Lua value whatsoever, and can be retrieved with get_user_value.

pub fn get_user_value<V>(&self) -> Result<V, Error>

where V: FromLua<'lua>,

Returns an associated value set by set_user_value.

Trait Implementations

impl<'lua> Clone for AnyUserData<'lua>

fn clone(&self) -> AnyUserData<'lua>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'lua> Debug for AnyUserData<'lua>

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

Formats the value using the given formatter.

impl<'lua> FromLua<'lua> for AnyUserData<'lua>

fn from_lua( value: Value<'lua>, _: Context<'lua>, ) -> Result<AnyUserData<'lua>, Error>

Performs the conversion.

impl<'lua> ToLua<'lua> for AnyUserData<'lua>

fn to_lua(self, _: Context<'lua>) -> Result<Value<'lua>, Error>

Performs the conversion.