Trait ImpliedPredicate

pub trait ImpliedPredicate<T: ?Sized>: HasAssoc<T, Impls = T> { }

Helper trait for the implied/entailed bounds trick.

Usage:

When you have:

//        this clause is not entailed
//               vvvvvvvv
trait SomeTrait<T : Clone>
where
    // And neither is this one.
    Self::SomeGat<true> : Send,
{
    type SomeGat<const IS_SEND: bool>;
    // …
}

instead, write:

use ::implied_bounds::ImpliedPredicate;

trait SomeTrait<T>
:
    ImpliedPredicate<T, Impls : Clone> +
    ImpliedPredicate<Self::SomeGat<true>, Impls : Send> +
{
    type SomeGat<const IS_SEND: bool>;
    // …
}

Convenience macro

Since this usage is not only not the most obvious to write, but more importantly, not very readable afterwards, this crate exposes a helper convenience macro which shall do this mechanical transformation in your stead; in an automated, reliable, and predictable manner.

use ::implied_bounds::implied_bounds;

#[implied_bounds] // 👈
trait SomeTrait<T : Clone>
where
    Self::SomeGat<true> : Send,
{
    type SomeGat<const IS_SEND: bool>;
    // …
}

And voilà 😙👌

Implementors

impl<T: ?Sized, Self_: ?Sized> ImpliedPredicate<T> for Self_