rustc_next_trait_solver/solve/
project_goals.rs

1use rustc_type_ir::{self as ty, Interner, ProjectionPredicate};
2use tracing::instrument;
3
4use crate::delegate::SolverDelegate;
5use crate::solve::{Certainty, EvalCtxt, Goal, GoalSource, QueryResult};
6
7impl<D, I> EvalCtxt<'_, D>
8where
9    D: SolverDelegate<Interner = I>,
10    I: Interner,
11{
12    #[instrument(level = "trace", skip(self), ret)]
13    pub(super) fn compute_projection_goal(
14        &mut self,
15        goal: Goal<I, ProjectionPredicate<I>>,
16    ) -> QueryResult<I> {
17        let cx = self.cx();
18        let projection_term = goal.predicate.projection_term.to_term(cx);
19        let goal = goal.with(
20            cx,
21            ty::PredicateKind::AliasRelate(
22                projection_term,
23                goal.predicate.term,
24                ty::AliasRelationDirection::Equate,
25            ),
26        );
27        self.add_goal(GoalSource::Misc, goal);
28        self.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
29    }
30}