diff options
4 files changed, 47 insertions, 0 deletions
diff --git a/compiler/rustc_next_trait_solver/src/solve/assembly/structural_traits.rs b/compiler/rustc_next_trait_solver/src/solve/assembly/structural_traits.rs index 035bfff89b5..b16f74cd8e4 100644 --- a/compiler/rustc_next_trait_solver/src/solve/assembly/structural_traits.rs +++ b/compiler/rustc_next_trait_solver/src/solve/assembly/structural_traits.rs @@ -724,6 +724,9 @@ pub(in crate::solve) fn const_conditions_for_destruct<I: Interner>( let destruct_def_id = cx.require_lang_item(TraitSolverLangItem::Destruct); match self_ty.kind() { + // `ManuallyDrop` is trivially `~const Destruct` as we do not run any drop glue on it. + ty::Adt(adt_def, _) if adt_def.is_manually_drop() => Ok(vec![]), + // An ADT is `~const Destruct` only if all of the fields are, // *and* if there is a `Drop` impl, that `Drop` impl is also `~const`. ty::Adt(adt_def, args) => { diff --git a/compiler/rustc_trait_selection/src/traits/effects.rs b/compiler/rustc_trait_selection/src/traits/effects.rs index defbafac20b..1b5dcef2e59 100644 --- a/compiler/rustc_trait_selection/src/traits/effects.rs +++ b/compiler/rustc_trait_selection/src/traits/effects.rs @@ -252,6 +252,9 @@ fn evaluate_host_effect_for_destruct_goal<'tcx>( let self_ty = obligation.predicate.self_ty(); let const_conditions = match *self_ty.kind() { + // `ManuallyDrop` is trivially `~const Destruct` as we do not run any drop glue on it. + ty::Adt(adt_def, _) if adt_def.is_manually_drop() => thin_vec![], + // An ADT is `~const Destruct` only if all of the fields are, // *and* if there is a `Drop` impl, that `Drop` impl is also `~const`. ty::Adt(adt_def, args) => { diff --git a/tests/ui/traits/const-traits/drop-manually-drop-no-drop-impl.rs b/tests/ui/traits/const-traits/drop-manually-drop-no-drop-impl.rs new file mode 100644 index 00000000000..060a543d6c3 --- /dev/null +++ b/tests/ui/traits/const-traits/drop-manually-drop-no-drop-impl.rs @@ -0,0 +1,17 @@ +//@[new] compile-flags: -Znext-solver +//@ revisions: old new +//@ check-pass + +use std::mem::ManuallyDrop; + +struct Moose; + +impl Drop for Moose { + fn drop(&mut self) {} +} + +struct ConstDropper<T>(ManuallyDrop<T>); + +const fn foo(_var: ConstDropper<Moose>) {} + +fn main() {} diff --git a/tests/ui/traits/const-traits/drop-manually-drop.rs b/tests/ui/traits/const-traits/drop-manually-drop.rs new file mode 100644 index 00000000000..62e8a815f10 --- /dev/null +++ b/tests/ui/traits/const-traits/drop-manually-drop.rs @@ -0,0 +1,24 @@ +//@[new] compile-flags: -Znext-solver +//@ revisions: old new +//@ check-pass + +#![feature(const_destruct)] +#![feature(const_trait_impl)] + +use std::mem::ManuallyDrop; + +struct Moose; + +impl Drop for Moose { + fn drop(&mut self) {} +} + +struct ConstDropper<T>(ManuallyDrop<T>); + +impl<T> const Drop for ConstDropper<T> { + fn drop(&mut self) {} +} + +const fn foo(_var: ConstDropper<Moose>) {} + +fn main() {} |