diff options
4 files changed, 15 insertions, 11 deletions
diff --git a/compiler/rustc_const_eval/src/interpret/eval_context.rs b/compiler/rustc_const_eval/src/interpret/eval_context.rs index 09e9cc4b35d..a9c127af8d5 100644 --- a/compiler/rustc_const_eval/src/interpret/eval_context.rs +++ b/compiler/rustc_const_eval/src/interpret/eval_context.rs @@ -1034,8 +1034,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { ) -> InterpResult<'tcx> { trace!("{:?} is now live", local); - // We avoid `ty.is_trivially_sized` since that (a) cannot assume WF, so it recurses through - // all fields of a tuple, and (b) does something expensive for ADTs. + // We avoid `ty.is_trivially_sized` since that does something expensive for ADTs. fn is_very_trivially_sized(ty: Ty<'_>) -> bool { match ty.kind() { ty::Infer(ty::IntVar(_) | ty::FloatVar(_)) @@ -1054,9 +1053,10 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { | ty::Closure(..) | ty::CoroutineClosure(..) | ty::Never - | ty::Error(_) => true, + | ty::Error(_) + | ty::Dynamic(_, _, ty::DynStar) => true, - ty::Str | ty::Slice(_) | ty::Dynamic(..) | ty::Foreign(..) => false, + ty::Str | ty::Slice(_) | ty::Dynamic(_, _, ty::Dyn) | ty::Foreign(..) => false, ty::Tuple(tys) => tys.last().iter().all(|ty| is_very_trivially_sized(**ty)), diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs index 7ff0b8dac4c..540936d7d8a 100644 --- a/compiler/rustc_middle/src/ty/sty.rs +++ b/compiler/rustc_middle/src/ty/sty.rs @@ -2484,13 +2484,16 @@ impl<'tcx> Ty<'tcx> { | ty::Closure(..) | ty::CoroutineClosure(..) | ty::Never - | ty::Error(_) => true, + | ty::Error(_) + | ty::Dynamic(_, _, ty::DynStar) => true, - ty::Str | ty::Slice(_) | ty::Dynamic(..) | ty::Foreign(..) => false, + ty::Str | ty::Slice(_) | ty::Dynamic(_, _, ty::Dyn) | ty::Foreign(..) => false, - ty::Tuple(tys) => tys.iter().all(|ty| ty.is_trivially_sized(tcx)), + ty::Tuple(tys) => tys.last().map_or(true, |ty| ty.is_trivially_sized(tcx)), - ty::Adt(def, _args) => def.sized_constraint(tcx).is_none(), + ty::Adt(def, args) => def + .sized_constraint(tcx) + .map_or(true, |ty| ty.instantiate(tcx, args).is_trivially_sized(tcx)), ty::Alias(..) | ty::Param(_) | ty::Placeholder(..) | ty::Bound(..) => false, diff --git a/compiler/rustc_trait_selection/src/solve/assembly/mod.rs b/compiler/rustc_trait_selection/src/solve/assembly/mod.rs index 9c7fa5216d7..9f33dce2a6d 100644 --- a/compiler/rustc_trait_selection/src/solve/assembly/mod.rs +++ b/compiler/rustc_trait_selection/src/solve/assembly/mod.rs @@ -128,7 +128,7 @@ pub(super) trait GoalKind<'tcx>: goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx>; - /// A type is `Copy` or `Clone` if its components are `Sized`. + /// A type is `Sized` if its tail component is `Sized`. /// /// These components are given by built-in rules from /// [`structural_traits::instantiate_constituent_tys_for_sized_trait`]. diff --git a/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs b/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs index 8822e55736f..e7e8ff66e3e 100644 --- a/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs +++ b/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs @@ -154,8 +154,9 @@ pub(in crate::solve) fn instantiate_constituent_tys_for_sized_trait<'tcx>( bug!("unexpected type `{ty}`") } - // impl Sized for (T1, T2, .., Tn) where T1: Sized, T2: Sized, .. Tn: Sized - ty::Tuple(tys) => Ok(tys.iter().map(ty::Binder::dummy).collect()), + // impl Sized for () + // impl Sized for (T1, T2, .., Tn) where Tn: Sized if n >= 1 + ty::Tuple(tys) => Ok(tys.last().map_or_else(Vec::new, |&ty| vec![ty::Binder::dummy(ty)])), // impl Sized for Adt<Args...> where sized_constraint(Adt)<Args...>: Sized // `sized_constraint(Adt)` is the deepest struct trail that can be determined |