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"); ```

With more complicated target

```rust

use delegate_attr::delegate;

use std::cell::RefCell;

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]); ```

into and call attribute

```rust

use delegate_attr::delegate;

struct Inner; impl Inner { pub fn method(&self, num: u32) -> u32 { num } }

struct Wrapper { inner: Inner }

[delegate(self.inner)]

impl Wrapper { // calls method, converts result to u64 #[into] pub fn method(&self, num: u32) -> u64;

// calls method, returns ()
#[call(method)]
pub fn method_noreturn(&self, num: u32);

} ```

Delegate single method

```rust

use delegate_attr::delegate;

struct Foo(Vec);

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

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