pub unsafe trait UserData: Sized + Clone {
type Target: NativeClass;
// Required methods
fn new(val: Self::Target) -> Self;
fn into_user_data(self) -> *const c_void;
unsafe fn consume_user_data_unchecked(ptr: *const c_void) -> Self;
unsafe fn clone_from_user_data_unchecked(ptr: *const c_void) -> Self;
}Expand description
Trait for customizable user-data wrappers.
See module-level documentation for detailed explanation on user-data.
Required Associated Types§
type Target: NativeClass
Required Methods§
Sourcefn new(val: Self::Target) -> Self
fn new(val: Self::Target) -> Self
Creates a new owned wrapper from a NativeClass instance.
This operation must never fail.
Sourcefn into_user_data(self) -> *const c_void
fn into_user_data(self) -> *const c_void
Takes a native instance and returns an opaque pointer that can be used to recover it.
This gives “ownership” to the engine.
This operation must never fail.
Sourceunsafe fn consume_user_data_unchecked(ptr: *const c_void) -> Self
unsafe fn consume_user_data_unchecked(ptr: *const c_void) -> Self
Takes an opaque pointer produced by into_user_data and “consumes” it to produce the
original instance, keeping the reference count.
This should be used when “ownership” is taken from the engine, i.e. destructors. Use elsewhere can lead to premature drops of the instance contained inside.
ptr is guaranteed to be non-null.
This operation must never fail.
§Safety
ptr must be pointing to valid data of the correct type.
Sourceunsafe fn clone_from_user_data_unchecked(ptr: *const c_void) -> Self
unsafe fn clone_from_user_data_unchecked(ptr: *const c_void) -> Self
Takes an opaque pointer produced by into_user_data and “clones” it to produce the
original instance, increasing the reference count.
This should be used when user data is “borrowed” from the engine.
ptr is guaranteed to be non-null.
This operation must never fail.
§Safety
ptr must be pointing to valid data of the correct type.
Dyn Compatibility§
This trait is not dyn compatible.
In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.