rustc_type_ir/
inherent.rs

1//! Set of traits which are used to emulate the inherent impls that are present in `rustc_middle`.
2//! It is customary to glob-import `rustc_type_ir::inherent::*` to bring all of these traits into
3//! scope when programming in interner-agnostic settings, and to avoid importing any of these
4//! directly elsewhere (i.e. specify the full path for an implementation downstream).
5
6use std::fmt::Debug;
7use std::hash::Hash;
8
9use rustc_ast_ir::Mutability;
10
11use crate::elaborate::Elaboratable;
12use crate::fold::{TypeFoldable, TypeSuperFoldable};
13use crate::relate::Relate;
14use crate::solve::{AdtDestructorKind, SizedTraitKind};
15use crate::visit::{Flags, TypeSuperVisitable, TypeVisitable, TypeVisitableExt};
16use crate::{self as ty, CollectAndApply, Interner, UpcastFrom};
17
18pub trait Ty<I: Interner<Ty = Self>>:
19    Copy
20    + Debug
21    + Hash
22    + Eq
23    + Into<I::GenericArg>
24    + Into<I::Term>
25    + IntoKind<Kind = ty::TyKind<I>>
26    + TypeSuperVisitable<I>
27    + TypeSuperFoldable<I>
28    + Relate<I>
29    + Flags
30{
31    fn new_unit(interner: I) -> Self;
32
33    fn new_bool(interner: I) -> Self;
34
35    fn new_u8(interner: I) -> Self;
36
37    fn new_usize(interner: I) -> Self;
38
39    fn new_infer(interner: I, var: ty::InferTy) -> Self;
40
41    fn new_var(interner: I, var: ty::TyVid) -> Self;
42
43    fn new_param(interner: I, param: I::ParamTy) -> Self;
44
45    fn new_placeholder(interner: I, param: I::PlaceholderTy) -> Self;
46
47    fn new_bound(interner: I, debruijn: ty::DebruijnIndex, var: I::BoundTy) -> Self;
48
49    fn new_anon_bound(interner: I, debruijn: ty::DebruijnIndex, var: ty::BoundVar) -> Self;
50
51    fn new_alias(interner: I, kind: ty::AliasTyKind, alias_ty: ty::AliasTy<I>) -> Self;
52
53    fn new_projection_from_args(interner: I, def_id: I::DefId, args: I::GenericArgs) -> Self {
54        Ty::new_alias(
55            interner,
56            ty::AliasTyKind::Projection,
57            ty::AliasTy::new_from_args(interner, def_id, args),
58        )
59    }
60
61    fn new_projection(
62        interner: I,
63        def_id: I::DefId,
64        args: impl IntoIterator<Item: Into<I::GenericArg>>,
65    ) -> Self {
66        Ty::new_alias(
67            interner,
68            ty::AliasTyKind::Projection,
69            ty::AliasTy::new(interner, def_id, args),
70        )
71    }
72
73    fn new_error(interner: I, guar: I::ErrorGuaranteed) -> Self;
74
75    fn new_adt(interner: I, adt_def: I::AdtDef, args: I::GenericArgs) -> Self;
76
77    fn new_foreign(interner: I, def_id: I::DefId) -> Self;
78
79    fn new_dynamic(
80        interner: I,
81        preds: I::BoundExistentialPredicates,
82        region: I::Region,
83        kind: ty::DynKind,
84    ) -> Self;
85
86    fn new_coroutine(interner: I, def_id: I::DefId, args: I::GenericArgs) -> Self;
87
88    fn new_coroutine_closure(interner: I, def_id: I::DefId, args: I::GenericArgs) -> Self;
89
90    fn new_closure(interner: I, def_id: I::DefId, args: I::GenericArgs) -> Self;
91
92    fn new_coroutine_witness(interner: I, def_id: I::DefId, args: I::GenericArgs) -> Self;
93
94    fn new_coroutine_witness_for_coroutine(
95        interner: I,
96        def_id: I::DefId,
97        coroutine_args: I::GenericArgs,
98    ) -> Self;
99
100    fn new_ptr(interner: I, ty: Self, mutbl: Mutability) -> Self;
101
102    fn new_ref(interner: I, region: I::Region, ty: Self, mutbl: Mutability) -> Self;
103
104    fn new_array_with_const_len(interner: I, ty: Self, len: I::Const) -> Self;
105
106    fn new_slice(interner: I, ty: Self) -> Self;
107
108    fn new_tup(interner: I, tys: &[I::Ty]) -> Self;
109
110    fn new_tup_from_iter<It, T>(interner: I, iter: It) -> T::Output
111    where
112        It: Iterator<Item = T>,
113        T: CollectAndApply<Self, Self>;
114
115    fn new_fn_def(interner: I, def_id: I::DefId, args: I::GenericArgs) -> Self;
116
117    fn new_fn_ptr(interner: I, sig: ty::Binder<I, ty::FnSig<I>>) -> Self;
118
119    fn new_pat(interner: I, ty: Self, pat: I::Pat) -> Self;
120
121    fn new_unsafe_binder(interner: I, ty: ty::Binder<I, I::Ty>) -> Self;
122
123    fn tuple_fields(self) -> I::Tys;
124
125    fn to_opt_closure_kind(self) -> Option<ty::ClosureKind>;
126
127    fn from_closure_kind(interner: I, kind: ty::ClosureKind) -> Self;
128
129    fn from_coroutine_closure_kind(interner: I, kind: ty::ClosureKind) -> Self;
130
131    fn is_ty_var(self) -> bool {
132        matches!(self.kind(), ty::Infer(ty::TyVar(_)))
133    }
134
135    fn is_ty_error(self) -> bool {
136        matches!(self.kind(), ty::Error(_))
137    }
138
139    fn is_floating_point(self) -> bool {
140        matches!(self.kind(), ty::Float(_) | ty::Infer(ty::FloatVar(_)))
141    }
142
143    fn is_integral(self) -> bool {
144        matches!(self.kind(), ty::Infer(ty::IntVar(_)) | ty::Int(_) | ty::Uint(_))
145    }
146
147    fn is_fn_ptr(self) -> bool {
148        matches!(self.kind(), ty::FnPtr(..))
149    }
150
151    /// Checks whether this type is an ADT that has unsafe fields.
152    fn has_unsafe_fields(self) -> bool;
153
154    fn fn_sig(self, interner: I) -> ty::Binder<I, ty::FnSig<I>> {
155        self.kind().fn_sig(interner)
156    }
157
158    fn discriminant_ty(self, interner: I) -> I::Ty;
159
160    fn is_known_rigid(self) -> bool {
161        self.kind().is_known_rigid()
162    }
163
164    fn is_guaranteed_unsized_raw(self) -> bool {
165        match self.kind() {
166            ty::Dynamic(_, _, ty::Dyn) | ty::Slice(_) | ty::Str => true,
167            ty::Bool
168            | ty::Char
169            | ty::Int(_)
170            | ty::Uint(_)
171            | ty::Float(_)
172            | ty::Adt(_, _)
173            | ty::Foreign(_)
174            | ty::Array(_, _)
175            | ty::Pat(_, _)
176            | ty::RawPtr(_, _)
177            | ty::Ref(_, _, _)
178            | ty::FnDef(_, _)
179            | ty::FnPtr(_, _)
180            | ty::UnsafeBinder(_)
181            | ty::Closure(_, _)
182            | ty::CoroutineClosure(_, _)
183            | ty::Coroutine(_, _)
184            | ty::CoroutineWitness(_, _)
185            | ty::Never
186            | ty::Tuple(_)
187            | ty::Alias(_, _)
188            | ty::Param(_)
189            | ty::Bound(_, _)
190            | ty::Placeholder(_)
191            | ty::Infer(_)
192            | ty::Error(_) => false,
193        }
194    }
195}
196
197pub trait Tys<I: Interner<Tys = Self>>:
198    Copy + Debug + Hash + Eq + SliceLike<Item = I::Ty> + TypeFoldable<I> + Default
199{
200    fn inputs(self) -> I::FnInputTys;
201
202    fn output(self) -> I::Ty;
203}
204
205pub trait Abi<I: Interner<Abi = Self>>: Copy + Debug + Hash + Eq {
206    fn rust() -> Self;
207
208    /// Whether this ABI is `extern "Rust"`.
209    fn is_rust(self) -> bool;
210}
211
212pub trait Safety<I: Interner<Safety = Self>>: Copy + Debug + Hash + Eq {
213    fn safe() -> Self;
214
215    fn is_safe(self) -> bool;
216
217    fn prefix_str(self) -> &'static str;
218}
219
220pub trait Region<I: Interner<Region = Self>>:
221    Copy
222    + Debug
223    + Hash
224    + Eq
225    + Into<I::GenericArg>
226    + IntoKind<Kind = ty::RegionKind<I>>
227    + Flags
228    + Relate<I>
229{
230    fn new_bound(interner: I, debruijn: ty::DebruijnIndex, var: I::BoundRegion) -> Self;
231
232    fn new_anon_bound(interner: I, debruijn: ty::DebruijnIndex, var: ty::BoundVar) -> Self;
233
234    fn new_static(interner: I) -> Self;
235
236    fn new_placeholder(interner: I, var: I::PlaceholderRegion) -> Self;
237
238    fn is_bound(self) -> bool {
239        matches!(self.kind(), ty::ReBound(..))
240    }
241}
242
243pub trait Const<I: Interner<Const = Self>>:
244    Copy
245    + Debug
246    + Hash
247    + Eq
248    + Into<I::GenericArg>
249    + Into<I::Term>
250    + IntoKind<Kind = ty::ConstKind<I>>
251    + TypeSuperVisitable<I>
252    + TypeSuperFoldable<I>
253    + Relate<I>
254    + Flags
255{
256    fn new_infer(interner: I, var: ty::InferConst) -> Self;
257
258    fn new_var(interner: I, var: ty::ConstVid) -> Self;
259
260    fn new_bound(interner: I, debruijn: ty::DebruijnIndex, bound_const: I::BoundConst) -> Self;
261
262    fn new_anon_bound(interner: I, debruijn: ty::DebruijnIndex, var: ty::BoundVar) -> Self;
263
264    fn new_placeholder(interner: I, param: I::PlaceholderConst) -> Self;
265
266    fn new_unevaluated(interner: I, uv: ty::UnevaluatedConst<I>) -> Self;
267
268    fn new_expr(interner: I, expr: I::ExprConst) -> Self;
269
270    fn new_error(interner: I, guar: I::ErrorGuaranteed) -> Self;
271
272    fn new_error_with_message(interner: I, msg: impl ToString) -> Self {
273        Self::new_error(interner, interner.delay_bug(msg))
274    }
275
276    fn is_ct_var(self) -> bool {
277        matches!(self.kind(), ty::ConstKind::Infer(ty::InferConst::Var(_)))
278    }
279
280    fn is_ct_error(self) -> bool {
281        matches!(self.kind(), ty::ConstKind::Error(_))
282    }
283}
284
285pub trait ValueConst<I: Interner<ValueConst = Self>>: Copy + Debug + Hash + Eq {
286    fn ty(self) -> I::Ty;
287    fn valtree(self) -> I::ValTree;
288}
289
290pub trait ExprConst<I: Interner<ExprConst = Self>>: Copy + Debug + Hash + Eq + Relate<I> {
291    fn args(self) -> I::GenericArgs;
292}
293
294pub trait GenericsOf<I: Interner<GenericsOf = Self>> {
295    fn count(&self) -> usize;
296}
297
298pub trait GenericArg<I: Interner<GenericArg = Self>>:
299    Copy
300    + Debug
301    + Hash
302    + Eq
303    + IntoKind<Kind = ty::GenericArgKind<I>>
304    + TypeVisitable<I>
305    + Relate<I>
306    + From<I::Ty>
307    + From<I::Region>
308    + From<I::Const>
309    + From<I::Term>
310{
311    fn as_term(&self) -> Option<I::Term> {
312        match self.kind() {
313            ty::GenericArgKind::Lifetime(_) => None,
314            ty::GenericArgKind::Type(ty) => Some(ty.into()),
315            ty::GenericArgKind::Const(ct) => Some(ct.into()),
316        }
317    }
318
319    fn as_type(&self) -> Option<I::Ty> {
320        if let ty::GenericArgKind::Type(ty) = self.kind() { Some(ty) } else { None }
321    }
322
323    fn expect_ty(&self) -> I::Ty {
324        self.as_type().expect("expected a type")
325    }
326
327    fn as_const(&self) -> Option<I::Const> {
328        if let ty::GenericArgKind::Const(c) = self.kind() { Some(c) } else { None }
329    }
330
331    fn expect_const(&self) -> I::Const {
332        self.as_const().expect("expected a const")
333    }
334
335    fn as_region(&self) -> Option<I::Region> {
336        if let ty::GenericArgKind::Lifetime(c) = self.kind() { Some(c) } else { None }
337    }
338
339    fn expect_region(&self) -> I::Region {
340        self.as_region().expect("expected a const")
341    }
342
343    fn is_non_region_infer(self) -> bool {
344        match self.kind() {
345            ty::GenericArgKind::Lifetime(_) => false,
346            ty::GenericArgKind::Type(ty) => ty.is_ty_var(),
347            ty::GenericArgKind::Const(ct) => ct.is_ct_var(),
348        }
349    }
350}
351
352pub trait Term<I: Interner<Term = Self>>:
353    Copy + Debug + Hash + Eq + IntoKind<Kind = ty::TermKind<I>> + TypeFoldable<I> + Relate<I>
354{
355    fn as_type(&self) -> Option<I::Ty> {
356        if let ty::TermKind::Ty(ty) = self.kind() { Some(ty) } else { None }
357    }
358
359    fn expect_ty(&self) -> I::Ty {
360        self.as_type().expect("expected a type, but found a const")
361    }
362
363    fn as_const(&self) -> Option<I::Const> {
364        if let ty::TermKind::Const(c) = self.kind() { Some(c) } else { None }
365    }
366
367    fn expect_const(&self) -> I::Const {
368        self.as_const().expect("expected a const, but found a type")
369    }
370
371    fn is_infer(self) -> bool {
372        match self.kind() {
373            ty::TermKind::Ty(ty) => ty.is_ty_var(),
374            ty::TermKind::Const(ct) => ct.is_ct_var(),
375        }
376    }
377
378    fn is_error(self) -> bool {
379        match self.kind() {
380            ty::TermKind::Ty(ty) => ty.is_ty_error(),
381            ty::TermKind::Const(ct) => ct.is_ct_error(),
382        }
383    }
384
385    fn to_alias_term(self) -> Option<ty::AliasTerm<I>> {
386        match self.kind() {
387            ty::TermKind::Ty(ty) => match ty.kind() {
388                ty::Alias(_kind, alias_ty) => Some(alias_ty.into()),
389                _ => None,
390            },
391            ty::TermKind::Const(ct) => match ct.kind() {
392                ty::ConstKind::Unevaluated(uv) => Some(uv.into()),
393                _ => None,
394            },
395        }
396    }
397}
398
399pub trait GenericArgs<I: Interner<GenericArgs = Self>>:
400    Copy + Debug + Hash + Eq + SliceLike<Item = I::GenericArg> + Default + Relate<I>
401{
402    fn rebase_onto(
403        self,
404        interner: I,
405        source_def_id: I::DefId,
406        target: I::GenericArgs,
407    ) -> I::GenericArgs;
408
409    fn type_at(self, i: usize) -> I::Ty;
410
411    fn region_at(self, i: usize) -> I::Region;
412
413    fn const_at(self, i: usize) -> I::Const;
414
415    fn identity_for_item(interner: I, def_id: I::DefId) -> I::GenericArgs;
416
417    fn extend_with_error(
418        interner: I,
419        def_id: I::DefId,
420        original_args: &[I::GenericArg],
421    ) -> I::GenericArgs;
422
423    fn split_closure_args(self) -> ty::ClosureArgsParts<I>;
424    fn split_coroutine_closure_args(self) -> ty::CoroutineClosureArgsParts<I>;
425    fn split_coroutine_args(self) -> ty::CoroutineArgsParts<I>;
426
427    fn as_closure(self) -> ty::ClosureArgs<I> {
428        ty::ClosureArgs { args: self }
429    }
430    fn as_coroutine_closure(self) -> ty::CoroutineClosureArgs<I> {
431        ty::CoroutineClosureArgs { args: self }
432    }
433    fn as_coroutine(self) -> ty::CoroutineArgs<I> {
434        ty::CoroutineArgs { args: self }
435    }
436}
437
438pub trait Predicate<I: Interner<Predicate = Self>>:
439    Copy
440    + Debug
441    + Hash
442    + Eq
443    + TypeSuperVisitable<I>
444    + TypeSuperFoldable<I>
445    + Flags
446    + UpcastFrom<I, ty::PredicateKind<I>>
447    + UpcastFrom<I, ty::Binder<I, ty::PredicateKind<I>>>
448    + UpcastFrom<I, ty::ClauseKind<I>>
449    + UpcastFrom<I, ty::Binder<I, ty::ClauseKind<I>>>
450    + UpcastFrom<I, I::Clause>
451    + UpcastFrom<I, ty::NormalizesTo<I>>
452    + UpcastFrom<I, ty::TraitRef<I>>
453    + UpcastFrom<I, ty::Binder<I, ty::TraitRef<I>>>
454    + UpcastFrom<I, ty::TraitPredicate<I>>
455    + UpcastFrom<I, ty::OutlivesPredicate<I, I::Ty>>
456    + UpcastFrom<I, ty::OutlivesPredicate<I, I::Region>>
457    + IntoKind<Kind = ty::Binder<I, ty::PredicateKind<I>>>
458    + Elaboratable<I>
459{
460    fn as_clause(self) -> Option<I::Clause>;
461
462    fn as_normalizes_to(self) -> Option<ty::Binder<I, ty::NormalizesTo<I>>> {
463        let kind = self.kind();
464        match kind.skip_binder() {
465            ty::PredicateKind::NormalizesTo(pred) => Some(kind.rebind(pred)),
466            _ => None,
467        }
468    }
469
470    // FIXME: Eventually uplift the impl out of rustc and make this defaulted.
471    fn allow_normalization(self) -> bool;
472}
473
474pub trait Clause<I: Interner<Clause = Self>>:
475    Copy
476    + Debug
477    + Hash
478    + Eq
479    + TypeFoldable<I>
480    + UpcastFrom<I, ty::Binder<I, ty::ClauseKind<I>>>
481    + UpcastFrom<I, ty::TraitRef<I>>
482    + UpcastFrom<I, ty::Binder<I, ty::TraitRef<I>>>
483    + UpcastFrom<I, ty::TraitPredicate<I>>
484    + UpcastFrom<I, ty::Binder<I, ty::TraitPredicate<I>>>
485    + UpcastFrom<I, ty::ProjectionPredicate<I>>
486    + UpcastFrom<I, ty::Binder<I, ty::ProjectionPredicate<I>>>
487    + IntoKind<Kind = ty::Binder<I, ty::ClauseKind<I>>>
488    + Elaboratable<I>
489{
490    fn as_predicate(self) -> I::Predicate;
491
492    fn as_trait_clause(self) -> Option<ty::Binder<I, ty::TraitPredicate<I>>> {
493        self.kind()
494            .map_bound(|clause| if let ty::ClauseKind::Trait(t) = clause { Some(t) } else { None })
495            .transpose()
496    }
497
498    fn as_host_effect_clause(self) -> Option<ty::Binder<I, ty::HostEffectPredicate<I>>> {
499        self.kind()
500            .map_bound(
501                |clause| if let ty::ClauseKind::HostEffect(t) = clause { Some(t) } else { None },
502            )
503            .transpose()
504    }
505
506    fn as_projection_clause(self) -> Option<ty::Binder<I, ty::ProjectionPredicate<I>>> {
507        self.kind()
508            .map_bound(
509                |clause| {
510                    if let ty::ClauseKind::Projection(p) = clause { Some(p) } else { None }
511                },
512            )
513            .transpose()
514    }
515
516    /// Performs a instantiation suitable for going from a
517    /// poly-trait-ref to supertraits that must hold if that
518    /// poly-trait-ref holds. This is slightly different from a normal
519    /// instantiation in terms of what happens with bound regions.
520    fn instantiate_supertrait(self, cx: I, trait_ref: ty::Binder<I, ty::TraitRef<I>>) -> Self;
521}
522
523pub trait Clauses<I: Interner<Clauses = Self>>:
524    Copy
525    + Debug
526    + Hash
527    + Eq
528    + TypeSuperVisitable<I>
529    + TypeSuperFoldable<I>
530    + Flags
531    + SliceLike<Item = I::Clause>
532{
533}
534
535/// Common capabilities of placeholder kinds
536pub trait PlaceholderLike<I: Interner>: Copy + Debug + Hash + Eq {
537    fn universe(self) -> ty::UniverseIndex;
538    fn var(self) -> ty::BoundVar;
539
540    type Bound: BoundVarLike<I>;
541    fn new(ui: ty::UniverseIndex, bound: Self::Bound) -> Self;
542    fn new_anon(ui: ty::UniverseIndex, var: ty::BoundVar) -> Self;
543    fn with_updated_universe(self, ui: ty::UniverseIndex) -> Self;
544}
545
546pub trait PlaceholderConst<I: Interner>: PlaceholderLike<I, Bound = I::BoundConst> {
547    fn find_const_ty_from_env(self, env: I::ParamEnv) -> I::Ty;
548}
549impl<I: Interner> PlaceholderConst<I> for I::PlaceholderConst {
550    fn find_const_ty_from_env(self, env: I::ParamEnv) -> I::Ty {
551        let mut candidates = env.caller_bounds().iter().filter_map(|clause| {
552            // `ConstArgHasType` are never desugared to be higher ranked.
553            match clause.kind().skip_binder() {
554                ty::ClauseKind::ConstArgHasType(placeholder_ct, ty) => {
555                    assert!(!(placeholder_ct, ty).has_escaping_bound_vars());
556
557                    match placeholder_ct.kind() {
558                        ty::ConstKind::Placeholder(placeholder_ct) if placeholder_ct == self => {
559                            Some(ty)
560                        }
561                        _ => None,
562                    }
563                }
564                _ => None,
565            }
566        });
567
568        // N.B. it may be tempting to fix ICEs by making this function return
569        // `Option<Ty<'tcx>>` instead of `Ty<'tcx>`; however, this is generally
570        // considered to be a bandaid solution, since it hides more important
571        // underlying issues with how we construct generics and predicates of
572        // items. It's advised to fix the underlying issue rather than trying
573        // to modify this function.
574        let ty = candidates.next().unwrap_or_else(|| {
575            panic!("cannot find `{self:?}` in param-env: {env:#?}");
576        });
577        assert!(
578            candidates.next().is_none(),
579            "did not expect duplicate `ConstParamHasTy` for `{self:?}` in param-env: {env:#?}"
580        );
581        ty
582    }
583}
584
585pub trait IntoKind {
586    type Kind;
587
588    fn kind(self) -> Self::Kind;
589}
590
591pub trait BoundVarLike<I: Interner>: Copy + Debug + Hash + Eq {
592    fn var(self) -> ty::BoundVar;
593
594    fn assert_eq(self, var: I::BoundVarKind);
595}
596
597pub trait ParamLike: Copy + Debug + Hash + Eq {
598    fn index(self) -> u32;
599}
600
601pub trait AdtDef<I: Interner>: Copy + Debug + Hash + Eq {
602    fn def_id(self) -> I::DefId;
603
604    fn is_struct(self) -> bool;
605
606    /// Returns the type of the struct tail.
607    ///
608    /// Expects the `AdtDef` to be a struct. If it is not, then this will panic.
609    fn struct_tail_ty(self, interner: I) -> Option<ty::EarlyBinder<I, I::Ty>>;
610
611    fn is_phantom_data(self) -> bool;
612
613    fn is_manually_drop(self) -> bool;
614
615    // FIXME: perhaps use `all_fields` and expose `FieldDef`.
616    fn all_field_tys(self, interner: I) -> ty::EarlyBinder<I, impl IntoIterator<Item = I::Ty>>;
617
618    fn sizedness_constraint(
619        self,
620        interner: I,
621        sizedness: SizedTraitKind,
622    ) -> Option<ty::EarlyBinder<I, I::Ty>>;
623
624    fn is_fundamental(self) -> bool;
625
626    fn destructor(self, interner: I) -> Option<AdtDestructorKind>;
627}
628
629pub trait ParamEnv<I: Interner>: Copy + Debug + Hash + Eq + TypeFoldable<I> {
630    fn caller_bounds(self) -> impl SliceLike<Item = I::Clause>;
631}
632
633pub trait Features<I: Interner>: Copy {
634    fn generic_const_exprs(self) -> bool;
635
636    fn coroutine_clone(self) -> bool;
637
638    fn associated_const_equality(self) -> bool;
639
640    fn feature_bound_holds_in_crate(self, symbol: I::Symbol) -> bool;
641}
642
643pub trait DefId<I: Interner>: Copy + Debug + Hash + Eq + TypeFoldable<I> {
644    fn is_local(self) -> bool;
645
646    fn as_local(self) -> Option<I::LocalDefId>;
647}
648
649pub trait BoundExistentialPredicates<I: Interner>:
650    Copy + Debug + Hash + Eq + Relate<I> + SliceLike<Item = ty::Binder<I, ty::ExistentialPredicate<I>>>
651{
652    fn principal_def_id(self) -> Option<I::TraitId>;
653
654    fn principal(self) -> Option<ty::Binder<I, ty::ExistentialTraitRef<I>>>;
655
656    fn auto_traits(self) -> impl IntoIterator<Item = I::TraitId>;
657
658    fn projection_bounds(
659        self,
660    ) -> impl IntoIterator<Item = ty::Binder<I, ty::ExistentialProjection<I>>>;
661}
662
663pub trait Span<I: Interner>: Copy + Debug + Hash + Eq + TypeFoldable<I> {
664    fn dummy() -> Self;
665}
666
667pub trait OpaqueTypeStorageEntries: Debug + Copy + Default {
668    /// Whether the number of opaques has changed in a way that necessitates
669    /// reevaluating a goal. For now, this is only when the number of non-duplicated
670    /// entries changed.
671    fn needs_reevaluation(self, canonicalized: usize) -> bool;
672}
673
674pub trait SliceLike: Sized + Copy {
675    type Item: Copy;
676    type IntoIter: Iterator<Item = Self::Item> + DoubleEndedIterator;
677
678    fn iter(self) -> Self::IntoIter;
679
680    fn as_slice(&self) -> &[Self::Item];
681
682    fn get(self, idx: usize) -> Option<Self::Item> {
683        self.as_slice().get(idx).copied()
684    }
685
686    fn len(self) -> usize {
687        self.as_slice().len()
688    }
689
690    fn is_empty(self) -> bool {
691        self.len() == 0
692    }
693
694    fn contains(self, t: &Self::Item) -> bool
695    where
696        Self::Item: PartialEq,
697    {
698        self.as_slice().contains(t)
699    }
700
701    fn to_vec(self) -> Vec<Self::Item> {
702        self.as_slice().to_vec()
703    }
704
705    fn last(self) -> Option<Self::Item> {
706        self.as_slice().last().copied()
707    }
708
709    fn split_last(&self) -> Option<(&Self::Item, &[Self::Item])> {
710        self.as_slice().split_last()
711    }
712}
713
714impl<'a, T: Copy> SliceLike for &'a [T] {
715    type Item = T;
716    type IntoIter = std::iter::Copied<std::slice::Iter<'a, T>>;
717
718    fn iter(self) -> Self::IntoIter {
719        self.iter().copied()
720    }
721
722    fn as_slice(&self) -> &[Self::Item] {
723        *self
724    }
725}
726
727impl<'a, T: Copy, const N: usize> SliceLike for &'a [T; N] {
728    type Item = T;
729    type IntoIter = std::iter::Copied<std::slice::Iter<'a, T>>;
730
731    fn iter(self) -> Self::IntoIter {
732        self.into_iter().copied()
733    }
734
735    fn as_slice(&self) -> &[Self::Item] {
736        *self
737    }
738}
739
740impl<'a, S: SliceLike> SliceLike for &'a S {
741    type Item = S::Item;
742    type IntoIter = S::IntoIter;
743
744    fn iter(self) -> Self::IntoIter {
745        (*self).iter()
746    }
747
748    fn as_slice(&self) -> &[Self::Item] {
749        (*self).as_slice()
750    }
751}
rustc_type_ir/inherent.rs

rustc_type_ir/
inherent.rs
