Struct rustc_trait_selection::infer::canonical::QueryResponse

pub struct QueryResponse<'tcx, R> {
    pub var_values: CanonicalVarValues<'tcx>,
    pub region_constraints: QueryRegionConstraints<'tcx>,
    pub certainty: Certainty,
    pub opaque_types: Vec<(OpaqueTypeKey<'tcx>, Ty<'tcx>), Global>,
    pub value: R,
}

After we execute a query with a canonicalized key, we get back a Canonical<QueryResponse<..>>. You can use instantiate_query_result to access the data in this result.

Fields

var_values: CanonicalVarValues<'tcx>

region_constraints: QueryRegionConstraints<'tcx>

certainty: Certainty

opaque_types: Vec<(OpaqueTypeKey<'tcx>, Ty<'tcx>), Global>

List of opaque types which we tried to compare to another type. Inside the query we don’t know yet whether the opaque type actually should get its hidden type inferred. So we bubble the opaque type and the type it was compared against upwards and let the query caller handle it.

value: R

Layout

Note: Unable to compute type layout, possibly due to this type having generic parameters. Layout can only be computed for concrete, fully-instantiated types.