Macro forward_as_ref 

macro_rules! forward_as_ref {
    (<$($generic:ident),+> in $($rest:tt)+) => { ... };
    (<const $($rest:tt)+) => { ... };
    (<$generic:ident, $($rest:tt)+) => { ... };
    (@impl [$($generic:tt)+] $this:ty => $target:ty) => { ... };
    (@impl [$($generic:tt)+] $this:ty => $field:ident : $target:ty) => { ... };
    ($this:ty => $target:ty) => { ... };
    ($this:ty => $field:ident : $target:ty) => { ... };
}

Implement AsRef by forwarding to a field’s implementation.

The first argument is the struct to create the impl for and the second is the target type produced by the field’s AsRef implementation.

Declare type and const parameters before in.

Examples

With a newtype struct:

use impl_more::forward_as_ref;

struct Foo(String);
forward_as_ref!(Foo => str);

let foo = Foo("bar".to_owned());
assert_eq!(foo.as_ref(), "bar");

With a named field struct and type parameters:

use impl_more::forward_as_ref;

struct Foo<T> { inner: Vec<T> }
forward_as_ref!(<T> in Foo<T> => inner: [T]);

let foo = Foo { inner: vec![1, 2, 3] };
assert_eq!(foo.as_ref(), &[1, 2, 3]);