Struct rustc_trait_selection::traits::fulfill::FulfillProcessor

struct FulfillProcessor<'a, 'tcx> {
    selcx: SelectionContext<'a, 'tcx>,
}

Fields

selcx: SelectionContext<'a, 'tcx>

Implementations

impl<'a, 'tcx> FulfillProcessor<'a, 'tcx>

fn process_trait_obligation( &mut self, obligation: &PredicateObligation<'tcx>, trait_obligation: PolyTraitObligation<'tcx>, stalled_on: &mut Vec<TyOrConstInferVar>, ) -> ProcessResult<PendingPredicateObligation<'tcx>, FulfillmentErrorCode<'tcx>>

fn process_projection_obligation( &mut self, obligation: &PredicateObligation<'tcx>, project_obligation: PolyProjectionObligation<'tcx>, stalled_on: &mut Vec<TyOrConstInferVar>, ) -> ProcessResult<PendingPredicateObligation<'tcx>, FulfillmentErrorCode<'tcx>>

Trait Implementations

impl<'a, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'tcx>

fn skippable_obligations<'b>( &'b self, it: impl Iterator<Item = &'b Self::Obligation>, ) -> usize

Compared to needs_process_obligation this and its callees contain some optimizations that come at the price of false negatives.

They

• reduce branching by covering only the most common case
• take a read-only view of the unification tables which allows skipping undo_log construction.
• bail out on value-cache misses in ena to avoid pointer chasing
• hoist RefCell locking out of the loop

fn needs_process_obligation( &self, pending_obligation: &Self::Obligation, ) -> bool

Identifies whether a predicate obligation needs processing.

This is always inlined because it has a single callsite and it is called very frequently. Be careful modifying this code! Several compile-time benchmarks are very sensitive to even small changes.

fn process_obligation( &mut self, pending_obligation: &mut PendingPredicateObligation<'tcx>, ) -> ProcessResult<PendingPredicateObligation<'tcx>, FulfillmentErrorCode<'tcx>>

Processes a predicate obligation and returns either:

• Changed(v) if the predicate is true, presuming that v are also true
• Unchanged if we don’t have enough info to be sure
• Error(e) if the predicate does not hold

This is called much less often than needs_process_obligation, so we never inline it.

type Obligation = PendingPredicateObligation<'tcx>

type Error = FulfillmentErrorCode<'tcx>

type OUT = Outcome<PendingPredicateObligation<'tcx>, FulfillmentErrorCode<'tcx>>

fn process_backedge<'c, I>( &mut self, cycle: I, _marker: PhantomData<&'c PendingPredicateObligation<'tcx>>, ) -> Result<(), FulfillmentErrorCode<'tcx>>

where I: Clone + Iterator<Item = &'c PendingPredicateObligation<'tcx>>,

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.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 152 bytes