pub trait InferCtxtBuilderExt<'tcx> {
// Required method
fn enter_canonical_trait_query<K, R>(
self,
canonical_key: &CanonicalQueryInput<'tcx, K>,
operation: impl FnOnce(&ObligationCtxt<'_, 'tcx>, K) -> Result<R, NoSolution>,
) -> Result<CanonicalQueryResponse<'tcx, R>, NoSolution>
where K: TypeFoldable<TyCtxt<'tcx>>,
R: Debug + TypeFoldable<TyCtxt<'tcx>>,
Canonical<'tcx, QueryResponse<'tcx, R>>: ArenaAllocatable<'tcx>;
}
Required Methods§
Sourcefn enter_canonical_trait_query<K, R>(
self,
canonical_key: &CanonicalQueryInput<'tcx, K>,
operation: impl FnOnce(&ObligationCtxt<'_, 'tcx>, K) -> Result<R, NoSolution>,
) -> Result<CanonicalQueryResponse<'tcx, R>, NoSolution>where
K: TypeFoldable<TyCtxt<'tcx>>,
R: Debug + TypeFoldable<TyCtxt<'tcx>>,
Canonical<'tcx, QueryResponse<'tcx, R>>: ArenaAllocatable<'tcx>,
fn enter_canonical_trait_query<K, R>(
self,
canonical_key: &CanonicalQueryInput<'tcx, K>,
operation: impl FnOnce(&ObligationCtxt<'_, 'tcx>, K) -> Result<R, NoSolution>,
) -> Result<CanonicalQueryResponse<'tcx, R>, NoSolution>where
K: TypeFoldable<TyCtxt<'tcx>>,
R: Debug + TypeFoldable<TyCtxt<'tcx>>,
Canonical<'tcx, QueryResponse<'tcx, R>>: ArenaAllocatable<'tcx>,
The “main method” for a canonicalized trait query. Given the
canonical key canonical_key
, this method will create a new
inference context, instantiate the key, and run your operation
op
. The operation should yield up a result (of type R
) as
well as a set of trait obligations that must be fully
satisfied. These obligations will be processed and the
canonical result created.
Returns NoSolution
in the event of any error.
(It might be mildly nicer to implement this on TyCtxt
, and
not InferCtxtBuilder
, but that is a bit tricky right now.
In part because we would need a for<'tcx>
sort of
bound for the closure and in part because it is convenient to
have 'tcx
be free on this function so that we can talk about
K: TypeFoldable<TyCtxt<'tcx>>
.)
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.