Trait input::Userdata [−] [src]

pub trait Userdata {
    unsafe fn userdata<T: 'static>(&self) -> Option<&T> { ... }
    unsafe fn userdata_mut<T: 'static>(&mut self) -> Option<&mut T> { ... }
    unsafe fn set_userdata<T: 'static, U: 'static>(&mut self,
                                                   new: Option<T>)
                                                   -> Option<U> { ... }
}

Trait to deal with userdata attached to this struct.

Provided Methods

Receive a reference to the attached userdata, if one exists.

Unsafety

Receiving userdata is unsafe as multiple references to the same underlying libinput struct may exist. As such any reference may become invalid if changed using set_userdata.

Receive a mutable reference to the attached userdata, if one exists.

Unsafety

Receiving userdata is unsafe as multiple references to the same underlying libinput struct may exist. As such any reference may become invalid if changed using set_userdata.

Additionally multiple mutable references may be created through the existance of multiple structs using the same libinput reference. If you have control over the userdata make sure to store Mutex to be on the safe side.

Set userdata and receive the currently set userdata

Sets new userdata or nothing in place of any existing one and returns the currently set userdata if one exists.

Unsafety

Multiple references to the same underlying libinput struct may exist. As such this function allows for shared mutable access, which is unsafe. Also this means this function might invalidate references to the currently set userdata, once dropped.

Use a Mutex when storing new userdata to mitiage some of these problems.

Note

Stored userdata is dropped correctly, if the last reference is hold by rust and goes out of scope normally.

Implementors