Struct rustc_trait_selection::solve::search_graph::StackEntry

struct StackEntry<'tcx> {
    input: CanonicalInput<'tcx>,
    available_depth: Limit,
    reached_depth: StackDepth,
    cycle_root_depth: StackDepth,
    encountered_overflow: bool,
    has_been_used: bool,
    provisional_result: Option<QueryResult<'tcx>>,
    cycle_participants: FxHashSet<CanonicalInput<'tcx>>,
}

Fields

input: CanonicalInput<'tcx>

available_depth: Limit

reached_depth: StackDepth

cycle_root_depth: StackDepth

encountered_overflow: bool

has_been_used: bool

provisional_result: Option<QueryResult<'tcx>>

Starts out as None and gets set when rerunning this goal in case we encounter a cycle.

cycle_participants: FxHashSet<CanonicalInput<'tcx>>

We put only the root goal of a coinductive cycle into the global cache.

If we were to use that result when later trying to prove another cycle participant, we can end up with unstable query results.

See tests/ui/new-solver/coinduction/incompleteness-unstable-result.rs for an example of where this is needed.

Trait Implementations

impl<'tcx> Debug for StackEntry<'tcx>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

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: 144 bytes