diff options
Diffstat (limited to 'compiler/rustc_middle/src/traits/select.rs')
| -rw-r--r-- | compiler/rustc_middle/src/traits/select.rs | 36 |
1 files changed, 19 insertions, 17 deletions
diff --git a/compiler/rustc_middle/src/traits/select.rs b/compiler/rustc_middle/src/traits/select.rs index f33421bba..734c2b61c 100644 --- a/compiler/rustc_middle/src/traits/select.rs +++ b/compiler/rustc_middle/src/traits/select.rs @@ -125,10 +125,8 @@ pub enum SelectionCandidate<'tcx> { /// This is a trait matching with a projected type as `Self`, and we found /// an applicable bound in the trait definition. The `usize` is an index - /// into the list returned by `tcx.item_bounds`. The constness is the - /// constness of the bound in the trait. - // FIXME(effects) do we need this constness - ProjectionCandidate(usize, ty::BoundConstness), + /// into the list returned by `tcx.item_bounds`. + ProjectionCandidate(usize), /// Implementation of a `Fn`-family trait by one of the anonymous types /// generated for an `||` expression. @@ -144,14 +142,18 @@ pub enum SelectionCandidate<'tcx> { /// generated for an async construct. FutureCandidate, - /// Implementation of an `Iterator` trait by one of the generator types - /// generated for a gen construct. + /// Implementation of an `Iterator` trait by one of the coroutine types + /// generated for a `gen` construct. IteratorCandidate, + /// Implementation of an `AsyncIterator` trait by one of the coroutine types + /// generated for a `async gen` construct. + AsyncIteratorCandidate, + /// Implementation of a `Fn`-family trait by one of the anonymous /// types generated for a fn pointer type (e.g., `fn(int) -> int`) FnPointerCandidate { - is_const: bool, + fn_host_effect: ty::Const<'tcx>, }, TraitAliasCandidate, @@ -180,8 +182,8 @@ pub enum SelectionCandidate<'tcx> { /// /// The evaluation results are ordered: /// - `EvaluatedToOk` implies `EvaluatedToOkModuloRegions` -/// implies `EvaluatedToAmbig` implies `EvaluatedToUnknown` -/// - `EvaluatedToErr` implies `EvaluatedToRecur` +/// implies `EvaluatedToAmbig` implies `EvaluatedToAmbigStackDependent` +/// - `EvaluatedToErr` implies `EvaluatedToErrStackDependent` /// - the "union" of evaluation results is equal to their maximum - /// all the "potential success" candidates can potentially succeed, /// so they are noops when unioned with a definite error, and within @@ -199,7 +201,7 @@ pub enum EvaluationResult { /// Evaluation is known to be ambiguous -- it *might* hold for some /// assignment of inference variables, but it might not. /// - /// While this has the same meaning as `EvaluatedToUnknown` -- we can't + /// While this has the same meaning as `EvaluatedToAmbigStackDependent` -- we can't /// know whether this obligation holds or not -- it is the result we /// would get with an empty stack, and therefore is cacheable. EvaluatedToAmbig, @@ -207,8 +209,8 @@ pub enum EvaluationResult { /// variables. We are somewhat imprecise there, so we don't actually /// know the real result. /// - /// This can't be trivially cached for the same reason as `EvaluatedToRecur`. - EvaluatedToUnknown, + /// This can't be trivially cached for the same reason as `EvaluatedToErrStackDependent`. + EvaluatedToAmbigStackDependent, /// Evaluation failed because we encountered an obligation we are already /// trying to prove on this branch. /// @@ -247,12 +249,12 @@ pub enum EvaluationResult { /// does not hold, because of the bound (which can indeed be satisfied /// by `SomeUnsizedType` from another crate). // - // FIXME: when an `EvaluatedToRecur` goes past its parent root, we + // FIXME: when an `EvaluatedToErrStackDependent` goes past its parent root, we // ought to convert it to an `EvaluatedToErr`, because we know // there definitely isn't a proof tree for that obligation. Not // doing so is still sound -- there isn't any proof tree, so the // branch still can't be a part of a minimal one -- but does not re-enable caching. - EvaluatedToRecur, + EvaluatedToErrStackDependent, /// Evaluation failed. EvaluatedToErr, } @@ -276,15 +278,15 @@ impl EvaluationResult { | EvaluatedToOk | EvaluatedToOkModuloRegions | EvaluatedToAmbig - | EvaluatedToUnknown => true, + | EvaluatedToAmbigStackDependent => true, - EvaluatedToErr | EvaluatedToRecur => false, + EvaluatedToErr | EvaluatedToErrStackDependent => false, } } pub fn is_stack_dependent(self) -> bool { match self { - EvaluatedToUnknown | EvaluatedToRecur => true, + EvaluatedToAmbigStackDependent | EvaluatedToErrStackDependent => true, EvaluatedToOkModuloOpaqueTypes | EvaluatedToOk |