src/librustc/traits/structural_impls.rs

   1 // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 use chalk_engine;
  12 use rustc_data_structures::accumulate_vec::AccumulateVec;
  13 use traits;
  14 use traits::project::Normalized;
  15 use ty::fold::{TypeFoldable, TypeFolder, TypeVisitor};
  16 use ty::{self, Lift, TyCtxt};
  17
  18 use std::fmt;
  19 use std::rc::Rc;
  20
  21 // structural impls for the structs in traits
  22
  23 impl<'tcx, T: fmt::Debug> fmt::Debug for Normalized<'tcx, T> {
  24     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  25         write!(f, "Normalized({:?},{:?})", self.value, self.obligations)
  26     }
  27 }
  28
  29 impl<'tcx, O: fmt::Debug> fmt::Debug for traits::Obligation<'tcx, O> {
  30     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  31         if ty::tls::with(|tcx| tcx.sess.verbose()) {
  32             write!(
  33                 f,
  34                 "Obligation(predicate={:?},cause={:?},depth={})",
  35                 self.predicate, self.cause, self.recursion_depth
  36             )
  37         } else {
  38             write!(
  39                 f,
  40                 "Obligation(predicate={:?},depth={})",
  41                 self.predicate, self.recursion_depth
  42             )
  43         }
  44     }
  45 }
  46
  47 impl<'tcx, N: fmt::Debug> fmt::Debug for traits::Vtable<'tcx, N> {
  48     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  49         match *self {
  50             super::VtableImpl(ref v) => write!(f, "{:?}", v),
  51
  52             super::VtableAutoImpl(ref t) => write!(f, "{:?}", t),
  53
  54             super::VtableClosure(ref d) => write!(f, "{:?}", d),
  55
  56             super::VtableGenerator(ref d) => write!(f, "{:?}", d),
  57
  58             super::VtableFnPointer(ref d) => write!(f, "VtableFnPointer({:?})", d),
  59
  60             super::VtableObject(ref d) => write!(f, "{:?}", d),
  61
  62             super::VtableParam(ref n) => write!(f, "VtableParam({:?})", n),
  63
  64             super::VtableBuiltin(ref d) => write!(f, "{:?}", d),
  65         }
  66     }
  67 }
  68
  69 impl<'tcx, N: fmt::Debug> fmt::Debug for traits::VtableImplData<'tcx, N> {
  70     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  71         write!(
  72             f,
  73             "VtableImpl(impl_def_id={:?}, substs={:?}, nested={:?})",
  74             self.impl_def_id, self.substs, self.nested
  75         )
  76     }
  77 }
  78
  79 impl<'tcx, N: fmt::Debug> fmt::Debug for traits::VtableGeneratorData<'tcx, N> {
  80     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  81         write!(
  82             f,
  83             "VtableGenerator(generator_def_id={:?}, substs={:?}, nested={:?})",
  84             self.generator_def_id, self.substs, self.nested
  85         )
  86     }
  87 }
  88
  89 impl<'tcx, N: fmt::Debug> fmt::Debug for traits::VtableClosureData<'tcx, N> {
  90     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  91         write!(
  92             f,
  93             "VtableClosure(closure_def_id={:?}, substs={:?}, nested={:?})",
  94             self.closure_def_id, self.substs, self.nested
  95         )
  96     }
  97 }
  98
  99 impl<'tcx, N: fmt::Debug> fmt::Debug for traits::VtableBuiltinData<N> {
 100     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 101         write!(f, "VtableBuiltin(nested={:?})", self.nested)
 102     }
 103 }
 104
 105 impl<'tcx, N: fmt::Debug> fmt::Debug for traits::VtableAutoImplData<N> {
 106     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 107         write!(
 108             f,
 109             "VtableAutoImplData(trait_def_id={:?}, nested={:?})",
 110             self.trait_def_id, self.nested
 111         )
 112     }
 113 }
 114
 115 impl<'tcx, N: fmt::Debug> fmt::Debug for traits::VtableObjectData<'tcx, N> {
 116     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 117         write!(
 118             f,
 119             "VtableObject(upcast={:?}, vtable_base={}, nested={:?})",
 120             self.upcast_trait_ref, self.vtable_base, self.nested
 121         )
 122     }
 123 }
 124
 125 impl<'tcx, N: fmt::Debug> fmt::Debug for traits::VtableFnPointerData<'tcx, N> {
 126     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 127         write!(
 128             f,
 129             "VtableFnPointer(fn_ty={:?}, nested={:?})",
 130             self.fn_ty, self.nested
 131         )
 132     }
 133 }
 134
 135 impl<'tcx> fmt::Debug for traits::FulfillmentError<'tcx> {
 136     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 137         write!(f, "FulfillmentError({:?},{:?})", self.obligation, self.code)
 138     }
 139 }
 140
 141 impl<'tcx> fmt::Debug for traits::FulfillmentErrorCode<'tcx> {
 142     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 143         match *self {
 144             super::CodeSelectionError(ref e) => write!(f, "{:?}", e),
 145             super::CodeProjectionError(ref e) => write!(f, "{:?}", e),
 146             super::CodeSubtypeError(ref a, ref b) => {
 147                 write!(f, "CodeSubtypeError({:?}, {:?})", a, b)
 148             }
 149             super::CodeAmbiguity => write!(f, "Ambiguity"),
 150         }
 151     }
 152 }
 153
 154 impl<'tcx> fmt::Debug for traits::MismatchedProjectionTypes<'tcx> {
 155     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 156         write!(f, "MismatchedProjectionTypes({:?})", self.err)
 157     }
 158 }
 159
 160 ///////////////////////////////////////////////////////////////////////////
 161 // Lift implementations
 162
 163 impl<'a, 'tcx> Lift<'tcx> for traits::SelectionError<'a> {
 164     type Lifted = traits::SelectionError<'tcx>;
 165     fn lift_to_tcx<'b, 'gcx>(&self, tcx: TyCtxt<'b, 'gcx, 'tcx>) -> Option<Self::Lifted> {
 166         match *self {
 167             super::Unimplemented => Some(super::Unimplemented),
 168             super::OutputTypeParameterMismatch(a, b, ref err) => {
 169                 tcx.lift(&(a, b)).and_then(|(a, b)| {
 170                     tcx.lift(err)
 171                         .map(|err| super::OutputTypeParameterMismatch(a, b, err))
 172                 })
 173             }
 174             super::TraitNotObjectSafe(def_id) => Some(super::TraitNotObjectSafe(def_id)),
 175             super::ConstEvalFailure(ref err) => tcx.lift(&**err).map(|err| super::ConstEvalFailure(
 176                 err.into(),
 177             )),
 178             super::Overflow => bug!(), // FIXME: ape ConstEvalFailure?
 179         }
 180     }
 181 }
 182
 183 impl<'a, 'tcx> Lift<'tcx> for traits::ObligationCauseCode<'a> {
 184     type Lifted = traits::ObligationCauseCode<'tcx>;
 185     fn lift_to_tcx<'b, 'gcx>(&self, tcx: TyCtxt<'b, 'gcx, 'tcx>) -> Option<Self::Lifted> {
 186         match *self {
 187             super::ReturnNoExpression => Some(super::ReturnNoExpression),
 188             super::MiscObligation => Some(super::MiscObligation),
 189             super::SliceOrArrayElem => Some(super::SliceOrArrayElem),
 190             super::TupleElem => Some(super::TupleElem),
 191             super::ProjectionWf(proj) => tcx.lift(&proj).map(super::ProjectionWf),
 192             super::ItemObligation(def_id) => Some(super::ItemObligation(def_id)),
 193             super::ReferenceOutlivesReferent(ty) => {
 194                 tcx.lift(&ty).map(super::ReferenceOutlivesReferent)
 195             }
 196             super::ObjectTypeBound(ty, r) => tcx.lift(&ty).and_then(|ty| {
 197                 tcx.lift(&r)
 198                     .and_then(|r| Some(super::ObjectTypeBound(ty, r)))
 199             }),
 200             super::ObjectCastObligation(ty) => tcx.lift(&ty).map(super::ObjectCastObligation),
 201             super::AssignmentLhsSized => Some(super::AssignmentLhsSized),
 202             super::TupleInitializerSized => Some(super::TupleInitializerSized),
 203             super::StructInitializerSized => Some(super::StructInitializerSized),
 204             super::VariableType(id) => Some(super::VariableType(id)),
 205             super::ReturnType(id) => Some(super::ReturnType(id)),
 206             super::SizedReturnType => Some(super::SizedReturnType),
 207             super::SizedYieldType => Some(super::SizedYieldType),
 208             super::RepeatVec => Some(super::RepeatVec),
 209             super::FieldSized(item) => Some(super::FieldSized(item)),
 210             super::ConstSized => Some(super::ConstSized),
 211             super::SharedStatic => Some(super::SharedStatic),
 212             super::BuiltinDerivedObligation(ref cause) => {
 213                 tcx.lift(cause).map(super::BuiltinDerivedObligation)
 214             }
 215             super::ImplDerivedObligation(ref cause) => {
 216                 tcx.lift(cause).map(super::ImplDerivedObligation)
 217             }
 218             super::CompareImplMethodObligation {
 219                 item_name,
 220                 impl_item_def_id,
 221                 trait_item_def_id,
 222             } => Some(super::CompareImplMethodObligation {
 223                 item_name,
 224                 impl_item_def_id,
 225                 trait_item_def_id,
 226             }),
 227             super::ExprAssignable => Some(super::ExprAssignable),
 228             super::MatchExpressionArm { arm_span, source } => Some(super::MatchExpressionArm {
 229                 arm_span,
 230                 source: source,
 231             }),
 232             super::IfExpression => Some(super::IfExpression),
 233             super::IfExpressionWithNoElse => Some(super::IfExpressionWithNoElse),
 234             super::MainFunctionType => Some(super::MainFunctionType),
 235             super::StartFunctionType => Some(super::StartFunctionType),
 236             super::IntrinsicType => Some(super::IntrinsicType),
 237             super::MethodReceiver => Some(super::MethodReceiver),
 238             super::BlockTailExpression(id) => Some(super::BlockTailExpression(id)),
 239             super::TrivialBound => Some(super::TrivialBound),
 240         }
 241     }
 242 }
 243
 244 impl<'a, 'tcx> Lift<'tcx> for traits::DerivedObligationCause<'a> {
 245     type Lifted = traits::DerivedObligationCause<'tcx>;
 246     fn lift_to_tcx<'b, 'gcx>(&self, tcx: TyCtxt<'b, 'gcx, 'tcx>) -> Option<Self::Lifted> {
 247         tcx.lift(&self.parent_trait_ref).and_then(|trait_ref| {
 248             tcx.lift(&*self.parent_code)
 249                 .map(|code| traits::DerivedObligationCause {
 250                     parent_trait_ref: trait_ref,
 251                     parent_code: Rc::new(code),
 252                 })
 253         })
 254     }
 255 }
 256
 257 impl<'a, 'tcx> Lift<'tcx> for traits::ObligationCause<'a> {
 258     type Lifted = traits::ObligationCause<'tcx>;
 259     fn lift_to_tcx<'b, 'gcx>(&self, tcx: TyCtxt<'b, 'gcx, 'tcx>) -> Option<Self::Lifted> {
 260         tcx.lift(&self.code).map(|code| traits::ObligationCause {
 261             span: self.span,
 262             body_id: self.body_id,
 263             code,
 264         })
 265     }
 266 }
 267
 268 // For codegen only.
 269 impl<'a, 'tcx> Lift<'tcx> for traits::Vtable<'a, ()> {
 270     type Lifted = traits::Vtable<'tcx, ()>;
 271     fn lift_to_tcx<'b, 'gcx>(&self, tcx: TyCtxt<'b, 'gcx, 'tcx>) -> Option<Self::Lifted> {
 272         match self.clone() {
 273             traits::VtableImpl(traits::VtableImplData {
 274                 impl_def_id,
 275                 substs,
 276                 nested,
 277             }) => tcx.lift(&substs).map(|substs| {
 278                 traits::VtableImpl(traits::VtableImplData {
 279                     impl_def_id,
 280                     substs,
 281                     nested,
 282                 })
 283             }),
 284             traits::VtableAutoImpl(t) => Some(traits::VtableAutoImpl(t)),
 285             traits::VtableGenerator(traits::VtableGeneratorData {
 286                 generator_def_id,
 287                 substs,
 288                 nested,
 289             }) => tcx.lift(&substs).map(|substs| {
 290                 traits::VtableGenerator(traits::VtableGeneratorData {
 291                     generator_def_id: generator_def_id,
 292                     substs: substs,
 293                     nested: nested,
 294                 })
 295             }),
 296             traits::VtableClosure(traits::VtableClosureData {
 297                 closure_def_id,
 298                 substs,
 299                 nested,
 300             }) => tcx.lift(&substs).map(|substs| {
 301                 traits::VtableClosure(traits::VtableClosureData {
 302                     closure_def_id,
 303                     substs,
 304                     nested,
 305                 })
 306             }),
 307             traits::VtableFnPointer(traits::VtableFnPointerData { fn_ty, nested }) => {
 308                 tcx.lift(&fn_ty).map(|fn_ty| {
 309                     traits::VtableFnPointer(traits::VtableFnPointerData { fn_ty, nested })
 310                 })
 311             }
 312             traits::VtableParam(n) => Some(traits::VtableParam(n)),
 313             traits::VtableBuiltin(n) => Some(traits::VtableBuiltin(n)),
 314             traits::VtableObject(traits::VtableObjectData {
 315                 upcast_trait_ref,
 316                 vtable_base,
 317                 nested,
 318             }) => tcx.lift(&upcast_trait_ref).map(|trait_ref| {
 319                 traits::VtableObject(traits::VtableObjectData {
 320                     upcast_trait_ref: trait_ref,
 321                     vtable_base,
 322                     nested,
 323                 })
 324             }),
 325         }
 326     }
 327 }
 328
 329 ///////////////////////////////////////////////////////////////////////////
 330 // TypeFoldable implementations.
 331
 332 impl<'tcx, O: TypeFoldable<'tcx>> TypeFoldable<'tcx> for traits::Obligation<'tcx, O> {
 333     fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
 334         traits::Obligation {
 335             cause: self.cause.clone(),
 336             recursion_depth: self.recursion_depth,
 337             predicate: self.predicate.fold_with(folder),
 338             param_env: self.param_env.fold_with(folder),
 339         }
 340     }
 341
 342     fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
 343         self.predicate.visit_with(visitor)
 344     }
 345 }
 346
 347 BraceStructTypeFoldableImpl! {
 348     impl<'tcx, N> TypeFoldable<'tcx> for traits::VtableImplData<'tcx, N> {
 349         impl_def_id, substs, nested
 350     } where N: TypeFoldable<'tcx>
 351 }
 352
 353 BraceStructTypeFoldableImpl! {
 354     impl<'tcx, N> TypeFoldable<'tcx> for traits::VtableGeneratorData<'tcx, N> {
 355         generator_def_id, substs, nested
 356     } where N: TypeFoldable<'tcx>
 357 }
 358
 359 BraceStructTypeFoldableImpl! {
 360     impl<'tcx, N> TypeFoldable<'tcx> for traits::VtableClosureData<'tcx, N> {
 361         closure_def_id, substs, nested
 362     } where N: TypeFoldable<'tcx>
 363 }
 364
 365 BraceStructTypeFoldableImpl! {
 366     impl<'tcx, N> TypeFoldable<'tcx> for traits::VtableAutoImplData<N> {
 367         trait_def_id, nested
 368     } where N: TypeFoldable<'tcx>
 369 }
 370
 371 BraceStructTypeFoldableImpl! {
 372     impl<'tcx, N> TypeFoldable<'tcx> for traits::VtableBuiltinData<N> {
 373         nested
 374     } where N: TypeFoldable<'tcx>
 375 }
 376
 377 BraceStructTypeFoldableImpl! {
 378     impl<'tcx, N> TypeFoldable<'tcx> for traits::VtableObjectData<'tcx, N> {
 379         upcast_trait_ref, vtable_base, nested
 380     } where N: TypeFoldable<'tcx>
 381 }
 382
 383 BraceStructTypeFoldableImpl! {
 384     impl<'tcx, N> TypeFoldable<'tcx> for traits::VtableFnPointerData<'tcx, N> {
 385         fn_ty,
 386         nested
 387     } where N: TypeFoldable<'tcx>
 388 }
 389
 390 EnumTypeFoldableImpl! {
 391     impl<'tcx, N> TypeFoldable<'tcx> for traits::Vtable<'tcx, N> {
 392         (traits::VtableImpl)(a),
 393         (traits::VtableAutoImpl)(a),
 394         (traits::VtableGenerator)(a),
 395         (traits::VtableClosure)(a),
 396         (traits::VtableFnPointer)(a),
 397         (traits::VtableParam)(a),
 398         (traits::VtableBuiltin)(a),
 399         (traits::VtableObject)(a),
 400     } where N: TypeFoldable<'tcx>
 401 }
 402
 403 BraceStructTypeFoldableImpl! {
 404     impl<'tcx, T> TypeFoldable<'tcx> for Normalized<'tcx, T> {
 405         value,
 406         obligations
 407     } where T: TypeFoldable<'tcx>
 408 }
 409
 410 impl<'tcx> fmt::Display for traits::WhereClause<'tcx> {
 411     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
 412         use traits::WhereClause::*;
 413
 414         match self {
 415             Implemented(trait_ref) => write!(fmt, "Implemented({})", trait_ref),
 416             ProjectionEq(projection) => write!(fmt, "ProjectionEq({})", projection),
 417             RegionOutlives(predicate) => write!(fmt, "RegionOutlives({})", predicate),
 418             TypeOutlives(predicate) => write!(fmt, "TypeOutlives({})", predicate),
 419         }
 420     }
 421 }
 422
 423 impl<'tcx> fmt::Display for traits::WellFormed<'tcx> {
 424     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
 425         use traits::WellFormed::*;
 426
 427         match self {
 428             Trait(trait_ref) => write!(fmt, "WellFormed({})", trait_ref),
 429             Ty(ty) => write!(fmt, "WellFormed({})", ty),
 430         }
 431     }
 432 }
 433
 434 impl<'tcx> fmt::Display for traits::FromEnv<'tcx> {
 435     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
 436         use traits::FromEnv::*;
 437
 438         match self {
 439             Trait(trait_ref) => write!(fmt, "FromEnv({})", trait_ref),
 440             Ty(ty) => write!(fmt, "FromEnv({})", ty),
 441         }
 442     }
 443 }
 444
 445 impl<'tcx> fmt::Display for traits::DomainGoal<'tcx> {
 446     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
 447         use traits::DomainGoal::*;
 448
 449         match self {
 450             Holds(wc) => write!(fmt, "{}", wc),
 451             WellFormed(wf) => write!(fmt, "{}", wf),
 452             FromEnv(from_env) => write!(fmt, "{}", from_env),
 453             Normalize(projection) => write!(fmt, "Normalize({})", projection),
 454         }
 455     }
 456 }
 457
 458 impl fmt::Display for traits::QuantifierKind {
 459     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
 460         use traits::QuantifierKind::*;
 461
 462         match self {
 463             Universal => write!(fmt, "forall"),
 464             Existential => write!(fmt, "exists"),
 465         }
 466     }
 467 }
 468
 469 impl<'tcx> fmt::Display for traits::Goal<'tcx> {
 470     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
 471         use traits::Goal::*;
 472
 473         match self {
 474             Implies(hypotheses, goal) => {
 475                 write!(fmt, "if (")?;
 476                 for (index, hyp) in hypotheses.iter().enumerate() {
 477                     if index > 0 {
 478                         write!(fmt, ", ")?;
 479                     }
 480                     write!(fmt, "{}", hyp)?;
 481                 }
 482                 write!(fmt, ") {{ {} }}", goal)
 483             }
 484             And(goal1, goal2) => write!(fmt, "({} && {})", goal1, goal2),
 485             Not(goal) => write!(fmt, "not {{ {} }}", goal),
 486             DomainGoal(goal) => write!(fmt, "{}", goal),
 487             Quantified(qkind, goal) => {
 488                 // FIXME: appropriate binder names
 489                 write!(fmt, "{}<> {{ {} }}", qkind, goal.skip_binder())
 490             }
 491             CannotProve => write!(fmt, "CannotProve"),
 492         }
 493     }
 494 }
 495
 496 impl<'tcx> fmt::Display for traits::ProgramClause<'tcx> {
 497     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
 498         let traits::ProgramClause { goal, hypotheses } = self;
 499         write!(fmt, "{}", goal)?;
 500         if !hypotheses.is_empty() {
 501             write!(fmt, " :- ")?;
 502             for (index, condition) in hypotheses.iter().enumerate() {
 503                 if index > 0 {
 504                     write!(fmt, ", ")?;
 505                 }
 506                 write!(fmt, "{}", condition)?;
 507             }
 508         }
 509         write!(fmt, ".")
 510     }
 511 }
 512
 513 impl<'tcx> fmt::Display for traits::Clause<'tcx> {
 514     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
 515         use traits::Clause::*;
 516
 517         match self {
 518             Implies(clause) => write!(fmt, "{}", clause),
 519             ForAll(clause) => {
 520                 // FIXME: appropriate binder names
 521                 write!(fmt, "forall<> {{ {} }}", clause.skip_binder())
 522             }
 523         }
 524     }
 525 }
 526
 527 EnumTypeFoldableImpl! {
 528     impl<'tcx> TypeFoldable<'tcx> for traits::WhereClause<'tcx> {
 529         (traits::WhereClause::Implemented)(trait_ref),
 530         (traits::WhereClause::ProjectionEq)(projection),
 531         (traits::WhereClause::TypeOutlives)(ty_outlives),
 532         (traits::WhereClause::RegionOutlives)(region_outlives),
 533     }
 534 }
 535
 536 EnumLiftImpl! {
 537     impl<'a, 'tcx> Lift<'tcx> for traits::WhereClause<'a> {
 538         type Lifted = traits::WhereClause<'tcx>;
 539         (traits::WhereClause::Implemented)(trait_ref),
 540         (traits::WhereClause::ProjectionEq)(projection),
 541         (traits::WhereClause::TypeOutlives)(ty_outlives),
 542         (traits::WhereClause::RegionOutlives)(region_outlives),
 543     }
 544 }
 545
 546 EnumTypeFoldableImpl! {
 547     impl<'tcx> TypeFoldable<'tcx> for traits::WellFormed<'tcx> {
 548         (traits::WellFormed::Trait)(trait_ref),
 549         (traits::WellFormed::Ty)(ty),
 550     }
 551 }
 552
 553 EnumLiftImpl! {
 554     impl<'a, 'tcx> Lift<'tcx> for traits::WellFormed<'a> {
 555         type Lifted = traits::WellFormed<'tcx>;
 556         (traits::WellFormed::Trait)(trait_ref),
 557         (traits::WellFormed::Ty)(ty),
 558     }
 559 }
 560
 561 EnumTypeFoldableImpl! {
 562     impl<'tcx> TypeFoldable<'tcx> for traits::FromEnv<'tcx> {
 563         (traits::FromEnv::Trait)(trait_ref),
 564         (traits::FromEnv::Ty)(ty),
 565     }
 566 }
 567
 568 EnumLiftImpl! {
 569     impl<'a, 'tcx> Lift<'tcx> for traits::FromEnv<'a> {
 570         type Lifted = traits::FromEnv<'tcx>;
 571         (traits::FromEnv::Trait)(trait_ref),
 572         (traits::FromEnv::Ty)(ty),
 573     }
 574 }
 575
 576 EnumTypeFoldableImpl! {
 577     impl<'tcx> TypeFoldable<'tcx> for traits::DomainGoal<'tcx> {
 578         (traits::DomainGoal::Holds)(wc),
 579         (traits::DomainGoal::WellFormed)(wf),
 580         (traits::DomainGoal::FromEnv)(from_env),
 581         (traits::DomainGoal::Normalize)(projection),
 582     }
 583 }
 584
 585 EnumLiftImpl! {
 586     impl<'a, 'tcx> Lift<'tcx> for traits::DomainGoal<'a> {
 587         type Lifted = traits::DomainGoal<'tcx>;
 588         (traits::DomainGoal::Holds)(wc),
 589         (traits::DomainGoal::WellFormed)(wf),
 590         (traits::DomainGoal::FromEnv)(from_env),
 591         (traits::DomainGoal::Normalize)(projection),
 592     }
 593 }
 594
 595 CloneTypeFoldableAndLiftImpls! {
 596     traits::QuantifierKind,
 597 }
 598
 599 EnumTypeFoldableImpl! {
 600     impl<'tcx> TypeFoldable<'tcx> for traits::Goal<'tcx> {
 601         (traits::Goal::Implies)(hypotheses, goal),
 602         (traits::Goal::And)(goal1, goal2),
 603         (traits::Goal::Not)(goal),
 604         (traits::Goal::DomainGoal)(domain_goal),
 605         (traits::Goal::Quantified)(qkind, goal),
 606         (traits::Goal::CannotProve),
 607     }
 608 }
 609
 610 EnumLiftImpl! {
 611     impl<'a, 'tcx> Lift<'tcx> for traits::Goal<'a> {
 612         type Lifted = traits::Goal<'tcx>;
 613         (traits::Goal::Implies)(hypotheses, goal),
 614         (traits::Goal::And)(goal1, goal2),
 615         (traits::Goal::Not)(goal),
 616         (traits::Goal::DomainGoal)(domain_goal),
 617         (traits::Goal::Quantified)(kind, goal),
 618         (traits::Goal::CannotProve),
 619     }
 620 }
 621
 622 impl<'tcx> TypeFoldable<'tcx> for &'tcx ty::Slice<traits::Goal<'tcx>> {
 623     fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
 624         let v = self.iter()
 625             .map(|t| t.fold_with(folder))
 626             .collect::<AccumulateVec<[_; 8]>>();
 627         folder.tcx().intern_goals(&v)
 628     }
 629
 630     fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
 631         self.iter().any(|t| t.visit_with(visitor))
 632     }
 633 }
 634
 635 impl<'tcx> TypeFoldable<'tcx> for &'tcx traits::Goal<'tcx> {
 636     fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
 637         let v = (**self).fold_with(folder);
 638         folder.tcx().mk_goal(v)
 639     }
 640
 641     fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
 642         (**self).visit_with(visitor)
 643     }
 644 }
 645
 646 BraceStructTypeFoldableImpl! {
 647     impl<'tcx> TypeFoldable<'tcx> for traits::ProgramClause<'tcx> {
 648         goal,
 649         hypotheses
 650     }
 651 }
 652
 653 EnumTypeFoldableImpl! {
 654     impl<'tcx> TypeFoldable<'tcx> for traits::Clause<'tcx> {
 655         (traits::Clause::Implies)(clause),
 656         (traits::Clause::ForAll)(clause),
 657     }
 658 }
 659
 660 impl<'tcx> TypeFoldable<'tcx> for &'tcx ty::Slice<traits::Clause<'tcx>> {
 661     fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
 662         let v = self.iter()
 663             .map(|t| t.fold_with(folder))
 664             .collect::<AccumulateVec<[_; 8]>>();
 665         folder.tcx().intern_clauses(&v)
 666     }
 667
 668     fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
 669         self.iter().any(|t| t.visit_with(visitor))
 670     }
 671 }
 672
 673 impl<'tcx, C> TypeFoldable<'tcx> for chalk_engine::ExClause<C>
 674 where
 675     C: traits::ExClauseFold<'tcx>,
 676     C::Substitution: Clone,
 677     C::RegionConstraint: Clone,
 678 {
 679     fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
 680         <C as traits::ExClauseFold>::fold_ex_clause_with(
 681             self,
 682             folder,
 683         )
 684     }
 685
 686     fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
 687         <C as traits::ExClauseFold>::visit_ex_clause_with(
 688             self,
 689             visitor,
 690         )
 691     }
 692 }
 693
 694 impl<'tcx, C> Lift<'tcx> for chalk_engine::ExClause<C>
 695 where
 696     C: chalk_engine::context::Context + Clone,
 697     C: traits::ExClauseLift<'tcx>,
 698 {
 699     type Lifted = C::LiftedExClause;
 700
 701     fn lift_to_tcx<'a, 'gcx>(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>) -> Option<Self::Lifted> {
 702         <C as traits::ExClauseLift>::lift_ex_clause_to_tcx(self, tcx)
 703     }
 704 }
 705
 706 EnumTypeFoldableImpl! {
 707     impl<'tcx, C> TypeFoldable<'tcx> for chalk_engine::DelayedLiteral<C> {
 708         (chalk_engine::DelayedLiteral::CannotProve)(a),
 709         (chalk_engine::DelayedLiteral::Negative)(a),
 710         (chalk_engine::DelayedLiteral::Positive)(a, b),
 711     } where
 712         C: chalk_engine::context::Context + Clone,
 713         C::CanonicalConstrainedSubst: TypeFoldable<'tcx>,
 714 }
 715
 716 EnumTypeFoldableImpl! {
 717     impl<'tcx, C> TypeFoldable<'tcx> for chalk_engine::Literal<C> {
 718         (chalk_engine::Literal::Negative)(a),
 719         (chalk_engine::Literal::Positive)(a),
 720     } where
 721         C: chalk_engine::context::Context + Clone,
 722         C::GoalInEnvironment: Clone + TypeFoldable<'tcx>,
 723 }
 724
 725 CloneTypeFoldableAndLiftImpls! {
 726     chalk_engine::TableIndex,
 727 }