Struct rlua::AnyUserData

pub struct AnyUserData<'lua>(_);

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: 'static + UserData>(&self) -> bool

Checks whether the type of this userdata is T.

pub fn borrow<T: 'static + UserData>(&self) -> Result<Ref<'_, T>>

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: 'static + UserData>(&self) -> Result<RefMut<'_, T>>

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: ToLua<'lua>>(&self, v: V) -> Result<()>

Sets an associated value to this AnyUserData.

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

Equivalent to set_i_user_value(v, 1)

pub fn set_i_user_value<V: ToLua<'lua>>(&self, v: V, n: c_int) -> Result<()>

Sets an associated value to this AnyUserData.

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

pub fn get_user_value<V: FromLua<'lua>>(&self) -> Result<V>

Returns an associated value set by set_user_value.

pub fn get_i_user_value<V: FromLua<'lua>>(&self, n: c_int) -> Result<V>

Returns an associated value set by set_i_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

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>>

Performs the conversion.

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

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

Performs the conversion.