diff options
| -rw-r--r-- | clippy_lints/src/lib.rs | 3 | ||||
| -rw-r--r-- | clippy_lints/src/non_copy_const.rs | 315 | ||||
| -rw-r--r-- | tests/ui-toml/borrow_interior_mutable_const/clippy.toml | 1 | ||||
| -rw-r--r-- | tests/ui-toml/borrow_interior_mutable_const/ignore.rs | 37 | ||||
| -rw-r--r-- | tests/ui-toml/declare_interior_mutable_const/clippy.toml | 1 | ||||
| -rw-r--r-- | tests/ui-toml/declare_interior_mutable_const/ignore.rs | 46 |
6 files changed, 270 insertions, 133 deletions
diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs index 2d02ce8b4f0..3f04746cbee 100644 --- a/clippy_lints/src/lib.rs +++ b/clippy_lints/src/lib.rs @@ -807,7 +807,8 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: suppress_restriction_lint_in_const, )) }); - store.register_late_pass(|_| Box::new(non_copy_const::NonCopyConst)); + let ignore_interior_mutability = conf.ignore_interior_mutability.clone(); + store.register_late_pass(move |_| Box::new(non_copy_const::NonCopyConst::new(ignore_interior_mutability.clone()))); store.register_late_pass(|_| Box::new(ptr_offset_with_cast::PtrOffsetWithCast)); store.register_late_pass(|_| Box::new(redundant_clone::RedundantClone)); store.register_late_pass(|_| Box::new(slow_vector_initialization::SlowVectorInit)); diff --git a/clippy_lints/src/non_copy_const.rs b/clippy_lints/src/non_copy_const.rs index 2b4e3260c56..613afa46a91 100644 --- a/clippy_lints/src/non_copy_const.rs +++ b/clippy_lints/src/non_copy_const.rs @@ -5,9 +5,10 @@ use std::ptr; use clippy_utils::diagnostics::span_lint_and_then; -use clippy_utils::in_constant; use clippy_utils::macros::macro_backtrace; +use clippy_utils::{def_path_def_ids, in_constant}; use if_chain::if_chain; +use rustc_data_structures::fx::FxHashSet; use rustc_hir::def::{DefKind, Res}; use rustc_hir::def_id::DefId; use rustc_hir::{ @@ -15,9 +16,10 @@ use rustc_hir::{ }; use rustc_lint::{LateContext, LateLintPass, Lint}; use rustc_middle::mir::interpret::{ErrorHandled, EvalToValTreeResult, GlobalId}; +use rustc_middle::query::Key; use rustc_middle::ty::adjustment::Adjust; use rustc_middle::ty::{self, Ty, TyCtxt}; -use rustc_session::{declare_lint_pass, declare_tool_lint}; +use rustc_session::{declare_tool_lint, impl_lint_pass}; use rustc_span::{sym, InnerSpan, Span}; use rustc_target::abi::VariantIdx; @@ -126,128 +128,6 @@ declare_clippy_lint! { "referencing `const` with interior mutability" } -fn is_unfrozen<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool { - // Ignore types whose layout is unknown since `is_freeze` reports every generic types as `!Freeze`, - // making it indistinguishable from `UnsafeCell`. i.e. it isn't a tool to prove a type is - // 'unfrozen'. However, this code causes a false negative in which - // a type contains a layout-unknown type, but also an unsafe cell like `const CELL: Cell<T>`. - // Yet, it's better than `ty.has_type_flags(TypeFlags::HAS_TY_PARAM | TypeFlags::HAS_PROJECTION)` - // since it works when a pointer indirection involves (`Cell<*const T>`). - // Making up a `ParamEnv` where every generic params and assoc types are `Freeze`is another option; - // but I'm not sure whether it's a decent way, if possible. - cx.tcx.layout_of(cx.param_env.and(ty)).is_ok() && !ty.is_freeze(cx.tcx, cx.param_env) -} - -fn is_value_unfrozen_raw<'tcx>( - cx: &LateContext<'tcx>, - result: Result<Option<ty::ValTree<'tcx>>, ErrorHandled>, - ty: Ty<'tcx>, -) -> bool { - fn inner<'tcx>(cx: &LateContext<'tcx>, val: ty::ValTree<'tcx>, ty: Ty<'tcx>) -> bool { - match *ty.kind() { - // the fact that we have to dig into every structs to search enums - // leads us to the point checking `UnsafeCell` directly is the only option. - ty::Adt(ty_def, ..) if ty_def.is_unsafe_cell() => true, - // As of 2022-09-08 miri doesn't track which union field is active so there's no safe way to check the - // contained value. - ty::Adt(def, ..) if def.is_union() => false, - ty::Array(ty, _) => val.unwrap_branch().iter().any(|field| inner(cx, *field, ty)), - ty::Adt(def, _) if def.is_union() => false, - ty::Adt(def, args) if def.is_enum() => { - let (&variant_index, fields) = val.unwrap_branch().split_first().unwrap(); - let variant_index = VariantIdx::from_u32(variant_index.unwrap_leaf().try_to_u32().ok().unwrap()); - fields - .iter() - .copied() - .zip( - def.variants()[variant_index] - .fields - .iter() - .map(|field| field.ty(cx.tcx, args)), - ) - .any(|(field, ty)| inner(cx, field, ty)) - }, - ty::Adt(def, args) => val - .unwrap_branch() - .iter() - .zip(def.non_enum_variant().fields.iter().map(|field| field.ty(cx.tcx, args))) - .any(|(field, ty)| inner(cx, *field, ty)), - ty::Tuple(tys) => val - .unwrap_branch() - .iter() - .zip(tys) - .any(|(field, ty)| inner(cx, *field, ty)), - _ => false, - } - } - result.map_or_else( - |err| { - // Consider `TooGeneric` cases as being unfrozen. - // This causes a false positive where an assoc const whose type is unfrozen - // have a value that is a frozen variant with a generic param (an example is - // `declare_interior_mutable_const::enums::BothOfCellAndGeneric::GENERIC_VARIANT`). - // However, it prevents a number of false negatives that is, I think, important: - // 1. assoc consts in trait defs referring to consts of themselves (an example is - // `declare_interior_mutable_const::traits::ConcreteTypes::ANOTHER_ATOMIC`). - // 2. a path expr referring to assoc consts whose type is doesn't have any frozen variants in trait - // defs (i.e. without substitute for `Self`). (e.g. borrowing - // `borrow_interior_mutable_const::trait::ConcreteTypes::ATOMIC`) - // 3. similar to the false positive above; but the value is an unfrozen variant, or the type has no - // enums. (An example is - // `declare_interior_mutable_const::enums::BothOfCellAndGeneric::UNFROZEN_VARIANT` and - // `declare_interior_mutable_const::enums::BothOfCellAndGeneric::NO_ENUM`). - // One might be able to prevent these FNs correctly, and replace this with `false`; - // e.g. implementing `has_frozen_variant` described above, and not running this function - // when the type doesn't have any frozen variants would be the 'correct' way for the 2nd - // case (that actually removes another suboptimal behavior (I won't say 'false positive') where, - // similar to 2., but with the a frozen variant) (e.g. borrowing - // `borrow_interior_mutable_const::enums::AssocConsts::TO_BE_FROZEN_VARIANT`). - // I chose this way because unfrozen enums as assoc consts are rare (or, hopefully, none). - matches!(err, ErrorHandled::TooGeneric(..)) - }, - |val| val.map_or(true, |val| inner(cx, val, ty)), - ) -} - -fn is_value_unfrozen_poly<'tcx>(cx: &LateContext<'tcx>, body_id: BodyId, ty: Ty<'tcx>) -> bool { - let def_id = body_id.hir_id.owner.to_def_id(); - let args = ty::GenericArgs::identity_for_item(cx.tcx, def_id); - let instance = ty::Instance::new(def_id, args); - let cid = rustc_middle::mir::interpret::GlobalId { - instance, - promoted: None, - }; - let param_env = cx.tcx.param_env(def_id).with_reveal_all_normalized(cx.tcx); - let result = cx.tcx.const_eval_global_id_for_typeck(param_env, cid, None); - is_value_unfrozen_raw(cx, result, ty) -} - -fn is_value_unfrozen_expr<'tcx>(cx: &LateContext<'tcx>, hir_id: HirId, def_id: DefId, ty: Ty<'tcx>) -> bool { - let args = cx.typeck_results().node_args(hir_id); - - let result = const_eval_resolve(cx.tcx, cx.param_env, ty::UnevaluatedConst::new(def_id, args), None); - is_value_unfrozen_raw(cx, result, ty) -} - -pub fn const_eval_resolve<'tcx>( - tcx: TyCtxt<'tcx>, - param_env: ty::ParamEnv<'tcx>, - ct: ty::UnevaluatedConst<'tcx>, - span: Option<Span>, -) -> EvalToValTreeResult<'tcx> { - match ty::Instance::resolve(tcx, param_env, ct.def, ct.args) { - Ok(Some(instance)) => { - let cid = GlobalId { - instance, - promoted: None, - }; - tcx.const_eval_global_id_for_typeck(param_env, cid, span) - }, - Ok(None) => Err(ErrorHandled::TooGeneric(span.unwrap_or(rustc_span::DUMMY_SP))), - Err(err) => Err(ErrorHandled::Reported(err.into(), span.unwrap_or(rustc_span::DUMMY_SP))), - } -} - #[derive(Copy, Clone)] enum Source { Item { item: Span }, @@ -292,13 +172,178 @@ fn lint(cx: &LateContext<'_>, source: Source) { }); } -declare_lint_pass!(NonCopyConst => [DECLARE_INTERIOR_MUTABLE_CONST, BORROW_INTERIOR_MUTABLE_CONST]); +#[derive(Clone)] +pub struct NonCopyConst { + ignore_interior_mutability: Vec<String>, + ignore_mut_def_ids: FxHashSet<DefId>, +} + +impl_lint_pass!(NonCopyConst => [DECLARE_INTERIOR_MUTABLE_CONST, BORROW_INTERIOR_MUTABLE_CONST]); + +impl NonCopyConst { + pub fn new(ignore_interior_mutability: Vec<String>) -> Self { + Self { + ignore_interior_mutability, + ignore_mut_def_ids: FxHashSet::default(), + } + } + + fn is_ty_ignored(&self, ty: Ty<'_>) -> bool { + matches!(ty.ty_adt_id(), Some(adt_id) if self.ignore_mut_def_ids.contains(&adt_id)) + } + + fn is_unfrozen<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool { + // Ignore types whose layout is unknown since `is_freeze` reports every generic types as `!Freeze`, + // making it indistinguishable from `UnsafeCell`. i.e. it isn't a tool to prove a type is + // 'unfrozen'. However, this code causes a false negative in which + // a type contains a layout-unknown type, but also an unsafe cell like `const CELL: Cell<T>`. + // Yet, it's better than `ty.has_type_flags(TypeFlags::HAS_TY_PARAM | TypeFlags::HAS_PROJECTION)` + // since it works when a pointer indirection involves (`Cell<*const T>`). + // Making up a `ParamEnv` where every generic params and assoc types are `Freeze`is another option; + // but I'm not sure whether it's a decent way, if possible. + cx.tcx.layout_of(cx.param_env.and(ty)).is_ok() && !ty.is_freeze(cx.tcx, cx.param_env) + } + + fn is_value_unfrozen_raw_inner<'tcx>(&self, cx: &LateContext<'tcx>, val: ty::ValTree<'tcx>, ty: Ty<'tcx>) -> bool { + if self.is_ty_ignored(ty) { + return false; + } + match *ty.kind() { + // the fact that we have to dig into every structs to search enums + // leads us to the point checking `UnsafeCell` directly is the only option. + ty::Adt(ty_def, ..) if ty_def.is_unsafe_cell() => true, + // As of 2022-09-08 miri doesn't track which union field is active so there's no safe way to check the + // contained value. + ty::Adt(def, ..) if def.is_union() => false, + ty::Array(ty, _) => val + .unwrap_branch() + .iter() + .any(|field| self.is_value_unfrozen_raw_inner(cx, *field, ty)), + ty::Adt(def, _) if def.is_union() => false, + ty::Adt(def, args) if def.is_enum() => { + let (&variant_index, fields) = val.unwrap_branch().split_first().unwrap(); + let variant_index = VariantIdx::from_u32(variant_index.unwrap_leaf().try_to_u32().ok().unwrap()); + fields + .iter() + .copied() + .zip( + def.variants()[variant_index] + .fields + .iter() + .map(|field| field.ty(cx.tcx, args)), + ) + .any(|(field, ty)| self.is_value_unfrozen_raw_inner(cx, field, ty)) + }, + ty::Adt(def, args) => val + .unwrap_branch() + .iter() + .zip(def.non_enum_variant().fields.iter().map(|field| field.ty(cx.tcx, args))) + .any(|(field, ty)| self.is_value_unfrozen_raw_inner(cx, *field, ty)), + ty::Tuple(tys) => val + .unwrap_branch() + .iter() + .zip(tys) + .any(|(field, ty)| self.is_value_unfrozen_raw_inner(cx, *field, ty)), + _ => false, + } + } + + fn is_value_unfrozen_raw<'tcx>( + &self, + cx: &LateContext<'tcx>, + result: Result<Option<ty::ValTree<'tcx>>, ErrorHandled>, + ty: Ty<'tcx>, + ) -> bool { + result.map_or_else( + |err| { + // Consider `TooGeneric` cases as being unfrozen. + // This causes a false positive where an assoc const whose type is unfrozen + // have a value that is a frozen variant with a generic param (an example is + // `declare_interior_mutable_const::enums::BothOfCellAndGeneric::GENERIC_VARIANT`). + // However, it prevents a number of false negatives that is, I think, important: + // 1. assoc consts in trait defs referring to consts of themselves (an example is + // `declare_interior_mutable_const::traits::ConcreteTypes::ANOTHER_ATOMIC`). + // 2. a path expr referring to assoc consts whose type is doesn't have any frozen variants in trait + // defs (i.e. without substitute for `Self`). (e.g. borrowing + // `borrow_interior_mutable_const::trait::ConcreteTypes::ATOMIC`) + // 3. similar to the false positive above; but the value is an unfrozen variant, or the type has no + // enums. (An example is + // `declare_interior_mutable_const::enums::BothOfCellAndGeneric::UNFROZEN_VARIANT` and + // `declare_interior_mutable_const::enums::BothOfCellAndGeneric::NO_ENUM`). + // One might be able to prevent these FNs correctly, and replace this with `false`; + // e.g. implementing `has_frozen_variant` described above, and not running this function + // when the type doesn't have any frozen variants would be the 'correct' way for the 2nd + // case (that actually removes another suboptimal behavior (I won't say 'false positive') where, + // similar to 2., but with the a frozen variant) (e.g. borrowing + // `borrow_interior_mutable_const::enums::AssocConsts::TO_BE_FROZEN_VARIANT`). + // I chose this way because unfrozen enums as assoc consts are rare (or, hopefully, none). + matches!(err, ErrorHandled::TooGeneric(..)) + }, + |val| val.map_or(true, |val| self.is_value_unfrozen_raw_inner(cx, val, ty)), + ) + } + + fn is_value_unfrozen_poly<'tcx>(&self, cx: &LateContext<'tcx>, body_id: BodyId, ty: Ty<'tcx>) -> bool { + let def_id = body_id.hir_id.owner.to_def_id(); + let args = ty::GenericArgs::identity_for_item(cx.tcx, def_id); + let instance = ty::Instance::new(def_id, args); + let cid = rustc_middle::mir::interpret::GlobalId { + instance, + promoted: None, + }; + let param_env = cx.tcx.param_env(def_id).with_reveal_all_normalized(cx.tcx); + let result = cx.tcx.const_eval_global_id_for_typeck(param_env, cid, None); + self.is_value_unfrozen_raw(cx, result, ty) + } + + fn is_value_unfrozen_expr<'tcx>(&self, cx: &LateContext<'tcx>, hir_id: HirId, def_id: DefId, ty: Ty<'tcx>) -> bool { + let args = cx.typeck_results().node_args(hir_id); + + let result = Self::const_eval_resolve(cx.tcx, cx.param_env, ty::UnevaluatedConst::new(def_id, args), None); + self.is_value_unfrozen_raw(cx, result, ty) + } + + pub fn const_eval_resolve<'tcx>( + tcx: TyCtxt<'tcx>, + param_env: ty::ParamEnv<'tcx>, + ct: ty::UnevaluatedConst<'tcx>, + span: Option<Span>, + ) -> EvalToValTreeResult<'tcx> { + match ty::Instance::resolve(tcx, param_env, ct.def, ct.args) { + Ok(Some(instance)) => { + let cid = GlobalId { + instance, + promoted: None, + }; + tcx.const_eval_global_id_for_typeck(param_env, cid, span) + }, + Ok(None) => Err(ErrorHandled::TooGeneric(span.unwrap_or(rustc_span::DUMMY_SP))), + Err(err) => Err(ErrorHandled::Reported(err.into(), span.unwrap_or(rustc_span::DUMMY_SP))), + } + } +} impl<'tcx> LateLintPass<'tcx> for NonCopyConst { + fn check_crate(&mut self, cx: &LateContext<'tcx>) { + self.ignore_mut_def_ids.clear(); + let mut path = Vec::new(); + for ty in &self.ignore_interior_mutability { + path.extend(ty.split("::")); + for id in def_path_def_ids(cx, &path[..]) { + self.ignore_mut_def_ids.insert(id); + } + path.clear(); + } + } + fn check_item(&mut self, cx: &LateContext<'tcx>, it: &'tcx Item<'_>) { if let ItemKind::Const(.., body_id) = it.kind { let ty = cx.tcx.type_of(it.owner_id).instantiate_identity(); - if !ignored_macro(cx, it) && is_unfrozen(cx, ty) && is_value_unfrozen_poly(cx, body_id, ty) { + if !ignored_macro(cx, it) + && !self.is_ty_ignored(ty) + && Self::is_unfrozen(cx, ty) + && self.is_value_unfrozen_poly(cx, body_id, ty) + { lint(cx, Source::Item { item: it.span }); } } @@ -311,7 +356,7 @@ impl<'tcx> LateLintPass<'tcx> for NonCopyConst { // Normalize assoc types because ones originated from generic params // bounded other traits could have their bound. let normalized = cx.tcx.normalize_erasing_regions(cx.param_env, ty); - if is_unfrozen(cx, normalized) + if !self.is_ty_ignored(ty) && Self::is_unfrozen(cx, normalized) // When there's no default value, lint it only according to its type; // in other words, lint consts whose value *could* be unfrozen, not definitely is. // This feels inconsistent with how the lint treats generic types, @@ -324,7 +369,7 @@ impl<'tcx> LateLintPass<'tcx> for NonCopyConst { // i.e. having an enum doesn't necessary mean a type has a frozen variant. // And, implementing it isn't a trivial task; it'll probably end up // re-implementing the trait predicate evaluation specific to `Freeze`. - && body_id_opt.map_or(true, |body_id| is_value_unfrozen_poly(cx, body_id, normalized)) + && body_id_opt.map_or(true, |body_id| self.is_value_unfrozen_poly(cx, body_id, normalized)) { lint(cx, Source::Assoc { item: trait_item.span }); } @@ -367,8 +412,8 @@ impl<'tcx> LateLintPass<'tcx> for NonCopyConst { // e.g. `layout_of(...).is_err() || has_frozen_variant(...);` let ty = cx.tcx.type_of(impl_item.owner_id).instantiate_identity(); let normalized = cx.tcx.normalize_erasing_regions(cx.param_env, ty); - if is_unfrozen(cx, normalized); - if is_value_unfrozen_poly(cx, *body_id, normalized); + if !self.is_ty_ignored(ty) && Self::is_unfrozen(cx, normalized); + if self.is_value_unfrozen_poly(cx, *body_id, normalized); then { lint( cx, @@ -384,7 +429,10 @@ impl<'tcx> LateLintPass<'tcx> for NonCopyConst { // Normalize assoc types originated from generic params. let normalized = cx.tcx.normalize_erasing_regions(cx.param_env, ty); - if is_unfrozen(cx, ty) && is_value_unfrozen_poly(cx, *body_id, normalized) { + if !self.is_ty_ignored(ty) + && Self::is_unfrozen(cx, ty) + && self.is_value_unfrozen_poly(cx, *body_id, normalized) + { lint(cx, Source::Assoc { item: impl_item.span }); } }, @@ -478,7 +526,10 @@ impl<'tcx> LateLintPass<'tcx> for NonCopyConst { cx.typeck_results().expr_ty(dereferenced_expr) }; - if is_unfrozen(cx, ty) && is_value_unfrozen_expr(cx, expr.hir_id, item_def_id, ty) { + if !self.is_ty_ignored(ty) + && Self::is_unfrozen(cx, ty) + && self.is_value_unfrozen_expr(cx, expr.hir_id, item_def_id, ty) + { lint(cx, Source::Expr { expr: expr.span }); } } diff --git a/tests/ui-toml/borrow_interior_mutable_const/clippy.toml b/tests/ui-toml/borrow_interior_mutable_const/clippy.toml new file mode 100644 index 00000000000..34a1036e891 --- /dev/null +++ b/tests/ui-toml/borrow_interior_mutable_const/clippy.toml @@ -0,0 +1 @@ +ignore-interior-mutability = ["borrow_interior_mutable_const_ignore::Counted"] \ No newline at end of file diff --git a/tests/ui-toml/borrow_interior_mutable_const/ignore.rs b/tests/ui-toml/borrow_interior_mutable_const/ignore.rs new file mode 100644 index 00000000000..79c7cef6ce1 --- /dev/null +++ b/tests/ui-toml/borrow_interior_mutable_const/ignore.rs @@ -0,0 +1,37 @@ +//@compile-flags: --crate-name borrow_interior_mutable_const_ignore + +#![warn(clippy::borrow_interior_mutable_const)] +#![allow(clippy::declare_interior_mutable_const)] + +use core::cell::Cell; +use std::cmp::{Eq, PartialEq}; +use std::collections::{HashMap, HashSet}; +use std::hash::{Hash, Hasher}; +use std::ops::Deref; +use std::sync::atomic::{AtomicUsize, Ordering}; + +struct Counted<T> { + count: AtomicUsize, + val: T, +} + +impl<T> Counted<T> { + const fn new(val: T) -> Self { + Self { + count: AtomicUsize::new(0), + val, + } + } +} + +enum OptionalCell { + Unfrozen(Counted<bool>), + Frozen, +} + +const UNFROZEN_VARIANT: OptionalCell = OptionalCell::Unfrozen(Counted::new(true)); +const FROZEN_VARIANT: OptionalCell = OptionalCell::Frozen; + +fn main() { + let _ = &UNFROZEN_VARIANT; +} diff --git a/tests/ui-toml/declare_interior_mutable_const/clippy.toml b/tests/ui-toml/declare_interior_mutable_const/clippy.toml new file mode 100644 index 00000000000..71d13212e2a --- /dev/null +++ b/tests/ui-toml/declare_interior_mutable_const/clippy.toml @@ -0,0 +1 @@ +ignore-interior-mutability = ["declare_interior_mutable_const_ignore::Counted"] \ No newline at end of file diff --git a/tests/ui-toml/declare_interior_mutable_const/ignore.rs b/tests/ui-toml/declare_interior_mutable_const/ignore.rs new file mode 100644 index 00000000000..6385cf4f852 --- /dev/null +++ b/tests/ui-toml/declare_interior_mutable_const/ignore.rs @@ -0,0 +1,46 @@ +//@compile-flags: --crate-name declare_interior_mutable_const_ignore + +#![warn(clippy::declare_interior_mutable_const)] +#![allow(clippy::borrow_interior_mutable_const)] + +use core::cell::Cell; +use std::cmp::{Eq, PartialEq}; +use std::collections::{HashMap, HashSet}; +use std::hash::{Hash, Hasher}; +use std::ops::Deref; +use std::sync::atomic::{AtomicUsize, Ordering}; + +struct Counted<T> { + count: AtomicUsize, + val: T, +} + +impl<T> Counted<T> { + const fn new(val: T) -> Self { + Self { + count: AtomicUsize::new(0), + val, + } + } +} + +enum OptionalCell { + Unfrozen(Counted<bool>), + Frozen, +} + +const UNFROZEN_VARIANT: OptionalCell = OptionalCell::Unfrozen(Counted::new(true)); +const FROZEN_VARIANT: OptionalCell = OptionalCell::Frozen; + +const fn unfrozen_variant() -> OptionalCell { + OptionalCell::Unfrozen(Counted::new(true)) +} + +const fn frozen_variant() -> OptionalCell { + OptionalCell::Frozen +} + +const UNFROZEN_VARIANT_FROM_FN: OptionalCell = unfrozen_variant(); +const FROZEN_VARIANT_FROM_FN: OptionalCell = frozen_variant(); + +fn main() {} |