[−][src]Trait emacs::Transfer

pub trait Transfer: Sized {
    fn type_name() -> &'static str;

    unsafe extern "C" fn finalizer(ptr: *mut c_void) { ... }
}

Allowing a type to be exposed to Lisp, where its values appear as opaque objects, or "embedded user pointers" (printed as #<user-ptr ...>).

When a (boxed) value of this type is transferred to Lisp, the GC becomes its owner. Afterwards, module code can only access it through immutable references.

Required methods

fn type_name() -> &'static str

Returns the name of this type. This is used to report runtime type error, when a function expects this type, but some Lisp code passes a different type of "user pointer".

Loading content...

Provided methods

unsafe extern "C" fn finalizer(ptr: *mut c_void)

Finalizes a value. This is called by the GC when it discards a value of this type. Module code that needs custom destructor logic should implement Drop, instead of overriding this.

This function also serves as a form of runtime type tag.

Loading content...

Implementations on Foreign Types

impl<T> Transfer for RefCell<T>[src]

impl<T> Transfer for Mutex<T>[src]

impl<T> Transfer for RwLock<T>[src]

Loading content...

Implementors

Loading content...