Struct flutter_rust_bridge::ffi::RustOpaque

#[repr(transparent)]
pub struct RustOpaque<T: ?Sized + DartSafe> { /* private fields */ }

A wrapper to transfer ownership of T to Dart.

This type is equivalent to an Option<Arc<T>>. The inner pointer may be None if a nullptr is received from Dart, signifying that this pointer has been disposed.

Extensions for [sync::RwLock] and [sync::Mutex] are provided.

Naming the inner type

When an RustOpaque<T> is transformed into a Dart type, T’s string representation undergoes some transformations to become a valid Dart type:

• Rust keywords (dyn, ’static, DartSafe, etc.) are automatically removed.
• ASCII alphanumerics are kept, all other characters are ignored.

Trait objects

Trait objects may be put behind opaque pointers, but they must implement DartSafe to be safely sent to Dart. For example, this declaration can be used across the FFI border:

use flutter_rust_bridge::*;
use std::fmt::Debug;
use std::panic::{UnwindSafe, RefUnwindSafe};

// Rust does not allow multiple non-auto traits in trait objects, so this
// is one workaround.
pub trait DartDebug: DartSafe + Debug {}

impl<T: DartSafe + Debug> DartDebug for T {}

pub struct DebugWrapper(pub RustOpaque<Box<dyn DartDebug>>);

// creating a DebugWrapper using the opaque_dyn macro
let wrap = DebugWrapper(opaque_dyn!("foobar"));
// it's possible to name it directly
pub struct DebugWrapper2(pub RustOpaque<Box<dyn Debug + Send + Sync + UnwindSafe + RefUnwindSafe>>);

Implementations

impl<T: DartSafe> RustOpaque<T>

pub fn try_unwrap(self) -> Result<T, Self>

impl<T: DartSafe> RustOpaque<T>

pub fn new(value: T) -> Self

Trait Implementations

impl<T: ?Sized + DartSafe> Clone for RustOpaque<T>

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug + ?Sized + DartSafe> Debug for RustOpaque<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T: ?Sized + DartSafe> Deref for RustOpaque<T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<T: ?Sized + DartSafe> From<Arc<T>> for RustOpaque<T>

fn from(ptr: Arc<T>) -> Self

Converts to this type from the input type.

impl<T: DartSafe> From<RustOpaque<T>> for DartAbi

fn from(value: RustOpaque<T>) -> Self

Converts to this type from the input type.