Trait DepNodeKey 

pub trait DepNodeKey<Tcx: DepContext>: Debug + Sized {
    // Required methods
    fn fingerprint_style() -> FingerprintStyle;
    fn to_fingerprint(&self, _: Tcx) -> Fingerprint;
    fn to_debug_str(&self, tcx: Tcx) -> String;
    fn recover(tcx: Tcx, dep_node: &DepNode) -> Option<Self>;
}

Trait for query keys as seen by dependency-node tracking.

Required Methods

fn fingerprint_style() -> FingerprintStyle

fn to_fingerprint(&self, _: Tcx) -> Fingerprint

This method turns a query key into an opaque Fingerprint to be used in DepNode.

fn to_debug_str(&self, tcx: Tcx) -> String

fn recover(tcx: Tcx, dep_node: &DepNode) -> Option<Self>

This method tries to recover the query key from the given DepNode, something which is needed when forcing DepNodes during red-green evaluation. The query system will only call this method if fingerprint_style() is not FingerprintStyle::Opaque. It is always valid to return None here, in which case incremental compilation will treat the query as having changed instead of forcing it.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<Tcx: DepContext, T> DepNodeKey<Tcx> for T

where T: for<'a> HashStable<StableHashingContext<'a>> + Debug,