Struct RepeatLt 

pub struct RepeatLt<T: ?Sized>(/* private fields */);

Merges the first two needed lifetimes.

If T needed ['a, 'b, 'c] then RepeatLt<T> needs ['b, 'c] where 'b will be used where 'a is needed in T.

This can be useful for trait objects where you want &'a (dyn Trait + 'a) instead of &'a (dyn Trait + 'b).

Examples

use ty_tag::{tag, modifiers::RepeatLt, Reify, l};

// Some random trait.
trait X {}

// We tag the trait object.
#[tag]
type Tag<'a> = dyn X + 'a;

fn with_lt<'a>() {
    // error: lifetime may not live long enough
    // is_tagged::<&dyn X, &'a (dyn X + 'a)>();

    is_tagged::<RepeatLt<&dyn X>, &'a (dyn X + 'a)>();
}
with_lt();

// Checks that T reifies to U.
fn is_tagged<'a, T: Reify<l!['a], Reified = U>, U>() {}

Trait Implementations

impl<T: Tag> Tag for RepeatLt<T>

type NeededLifetimes = <<T as Tag>::NeededLifetimes as HoleList>::HoleTail

The needed lifetimes by the tagged type.

impl<Group: ?Sized, T: ?Sized + Tagged<Group>> Tagged<Group> for RepeatLt<T>

type Tag = RepeatLt<<T as Tagged<Group>>::Tag>

The tag for Self within the group Group.

impl<T: WithLt<Cons<L::Head, L>>, L: LifetimeList> WithLt<L> for RepeatLt<T>

where Cons<L::Head, L>: LifetimeList,

type Reified = <T as WithLt<Cons<<L as FirstLifetime>::Head, L>>>::Reified

The type tagged.