Struct mlua::prelude::LuaAnyUserData

pub struct LuaAnyUserData<'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<UserDataRef<'_, 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<UserDataRefMut<'_, T>>

Borrow this userdata mutably if it is of type T.

Errors

Returns a UserDataBorrowMutError if the userdata cannot be mutably 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 get_user_value. As Lua < 5.3 allows to store only tables, the value will be stored in a table at index 1.

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

Returns an associated value set by set_user_value.

For Lua < 5.3 the value will be automatically extracted from the table wrapper from index 1.

pub fn get_metatable(&self) -> Result<UserDataMetatable<'lua>>

Returns a metatable of this UserData.

Returned UserDataMetatable object wraps the original metatable and provides safe access to its methods.

For T: UserData + 'static returned metatable is shared among all instances of type T.

Trait Implementations

impl<'lua> AsRef<AnyUserData<'lua>> for AnyUserData<'lua>

fn as_ref(&self) -> &Self

Performs the conversion.

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>, _: &'lua Lua) -> Result<AnyUserData<'lua>>

Performs the conversion.

impl<'lua> PartialEq<AnyUserData<'lua>> for AnyUserData<'lua>

fn eq(&self, other: &Self) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<'lua> Serialize for AnyUserData<'lua>

fn serialize<S>(&self, serializer: S) -> StdResult<S::Ok, S::Error> where
    S: Serializer, 

Serialize this value into the given Serde serializer.

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

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

Performs the conversion.