Support overriding methods

[ChrisMGeo]

How would I prevent Delegate from delegating every method in a trait, so I can override some.

use ambassador::{delegatable_trait, Delegate};

#[delegatable_trait]
trait SomeTrait {
    fn get_val(&self) -> f64;
    fn some_other_thing(&self) {}
}
struct SomeTraitImpl;
impl SomeTrait for SomeTraitImpl {
    fn get_val(&self) -> f64 {
        0.0
    }
}
#[derive(Delegate)]
#[delegate(SomeTrait, target = "owned")]
struct SomeTraitImplOwner {
    owned: SomeTraitImpl,
}
impl SomeTraitImplOwner {
    fn get_val(&self) -> f64 {
        self.owned.get_val() + 1.0
    }
}
impl SomeTrait for SomeTraitImplOwner { // <- Error here
    fn get_val(&self) -> f64 {
        SomeTraitImplOwner::get_val(self)
    }
}

[dewert99]

This wasn't a planned use case but it would be possible to do this:

use ambassador::{delegatable_trait_remote};

trait SomeTrait {
    fn get_val(&self) -> f64;
    fn some_other_thing(&self) {}
}

// delegatable_trait_remote doesn't generate a new trait, just a delegation macro
#[delegatable_trait_remote]
trait SomeTraitPartial {
    // methods you want to delegate:
    fn some_other_thing(&self);
}

struct SomeTraitImpl;
impl SomeTrait for SomeTraitImpl {
    fn get_val(&self) -> f64 {
        0.0
    }
}

struct SomeTraitImplOwner {
    owned: SomeTraitImpl,
}
impl SomeTraitImplOwner {
    fn get_val(&self) -> f64 {
        self.owned.get_val() + 1.0
    }
}
impl SomeTrait for SomeTraitImplOwner { // <- Error here
    fn get_val(&self) -> f64 {
        SomeTraitImplOwner::get_val(self)
    }

    // since delegated and overridden methods need to be in the same impl block we can't use the `derive` syntax
   
    ambassador_impl_SomeTraitPartial!{body_struct (< >, SomeTraitImpl, owned)}
    // trait generics ------------------------------^         ^          ^
    // type of field being delegated to ----------------------^          ^
    // name of field being delegated ------------------------------------^
}