delegate-attr

Attribute proc-macro to delegate method to a field.

Examples

Delegate impl block

```rust use delegate_attr::delegate;

struct Foo(String);

[delegate(self.0)]

impl Foo { fn asstr(&self) -> &str; fn intobytes(self) -> Vec; }

let foo = Foo("hello".toowned()); asserteq!(foo.asstr(), "hello"); asserteq!(foo.into_bytes(), b"hello"); ```

```rust struct Foo { inner: RefCell>, }

[delegate(self.inner.borrow())]

impl Foo { fn len(&self) -> usize; }

[delegate(self.inner.borrow_mut())]

impl Foo { fn push(&self, value: T); }

[delegate(self.inner.into_inner())]

impl Foo { fn intoboxedslice(self) -> Box<[T]>; }

let foo = Foo { inner: RefCell::new(vec![1]) }; asserteq!(foo.len(), 1); foo.push(2); asserteq!(foo.len(), 2); asserteq!(foo.intoboxedslice().asref(), &[1, 2]); ```

Delegate single method

```rust struct Foo(Vec);

impl Foo { #[delegate(self.0)] fn len(&self) -> usize; }

let foo = Foo(vec![1]); assert_eq!(foo.len(), 1); ```