Trait rustc_ap_rustc_data_structures::obligation_forest::ObligationProcessor

pub trait ObligationProcessor {
    type Obligation: ForestObligation;
    type Error: Debug;
    fn process_obligation(
        &mut self, 
        obligation: &mut Self::Obligation
    ) -> ProcessResult<Self::Obligation, Self::Error>;
    fn process_backedge<'c, I>(
        &mut self, 
        cycle: I, 
        _marker: PhantomData<&'c Self::Obligation>
    )
    where
        I: Clone + Iterator<Item = &'c Self::Obligation>;
}

Associated Types

type Obligation: ForestObligation

type Error: Debug

Required methods

fn process_obligation(
    &mut self,
    obligation: &mut Self::Obligation
) -> ProcessResult<Self::Obligation, Self::Error>

fn process_backedge<'c, I>(
    &mut self,
    cycle: I,
    _marker: PhantomData<&'c Self::Obligation>
) where
    I: Clone + Iterator<Item = &'c Self::Obligation>, 

As we do the cycle check, we invoke this callback when we encounter an actual cycle. cycle is an iterator that starts at the start of the cycle in the stack and walks toward the top.

In other words, if we had O1 which required O2 which required O3 which required O1, we would give an iterator yielding O1, O2, O3 (O1 is not yielded twice).

Implementors