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 traits;
  12 use traits::project::Normalized;
  13 use ty::{self, Lift, TyCtxt};
  14 use ty::fold::{TypeFoldable, TypeFolder, TypeVisitor};
  15
  16 use std::fmt;
  17 use std::rc::Rc;
  18
  19 // structural impls for the structs in traits
  20
  21 impl<'tcx, T: fmt::Debug> fmt::Debug for Normalized<'tcx, T> {
  22     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  23         write!(f, "Normalized({:?},{:?})",
  24                self.value,
  25                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!(f, "Obligation(predicate={:?},cause={:?},depth={})",
  33                    self.predicate,
  34                    self.cause,
  35                    self.recursion_depth)
  36         } else {
  37             write!(f, "Obligation(predicate={:?},depth={})",
  38                    self.predicate,
  39                    self.recursion_depth)
  40         }
  41     }
  42 }
  43
  44 impl<'tcx, N: fmt::Debug> fmt::Debug for traits::Vtable<'tcx, N> {
  45     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  46         match *self {
  47             super::VtableImpl(ref v) =>
  48                 write!(f, "{:?}", v),
  49
  50             super::VtableAutoImpl(ref t) =>
  51                 write!(f, "{:?}", t),
  52
  53             super::VtableClosure(ref d) =>
  54                 write!(f, "{:?}", d),
  55
  56             super::VtableGenerator(ref d) =>
  57                 write!(f, "{:?}", d),
  58
  59             super::VtableFnPointer(ref d) =>
  60                 write!(f, "VtableFnPointer({:?})", d),
  61
  62             super::VtableObject(ref d) =>
  63                 write!(f, "{:?}", d),
  64
  65             super::VtableParam(ref n) =>
  66                 write!(f, "VtableParam({:?})", n),
  67
  68             super::VtableBuiltin(ref d) =>
  69                 write!(f, "{:?}", d)
  70         }
  71     }
  72 }
  73
  74 impl<'tcx, N: fmt::Debug> fmt::Debug for traits::VtableImplData<'tcx, N> {
  75     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  76         write!(f, "VtableImpl(impl_def_id={:?}, substs={:?}, nested={:?})",
  77                self.impl_def_id,
  78                self.substs,
  79                self.nested)
  80     }
  81 }
  82
  83 impl<'tcx, N: fmt::Debug> fmt::Debug for traits::VtableGeneratorData<'tcx, N> {
  84     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  85         write!(f, "VtableGenerator(closure_def_id={:?}, substs={:?}, nested={:?})",
  86                self.closure_def_id,
  87                self.substs,
  88                self.nested)
  89     }
  90 }
  91
  92 impl<'tcx, N: fmt::Debug> fmt::Debug for traits::VtableClosureData<'tcx, N> {
  93     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  94         write!(f, "VtableClosure(closure_def_id={:?}, substs={:?}, nested={:?})",
  95                self.closure_def_id,
  96                self.substs,
  97                self.nested)
  98     }
  99 }
 100
 101 impl<'tcx, N: fmt::Debug> fmt::Debug for traits::VtableBuiltinData<N> {
 102     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 103         write!(f, "VtableBuiltin(nested={:?})", self.nested)
 104     }
 105 }
 106
 107 impl<'tcx, N: fmt::Debug> fmt::Debug for traits::VtableAutoImplData<N> {
 108     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 109         write!(f, "VtableAutoImplData(trait_def_id={:?}, nested={:?})",
 110                self.trait_def_id,
 111                self.nested)
 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!(f, "VtableObject(upcast={:?}, vtable_base={}, nested={:?})",
 118                self.upcast_trait_ref,
 119                self.vtable_base,
 120                self.nested)
 121     }
 122 }
 123
 124 impl<'tcx, N: fmt::Debug> fmt::Debug for traits::VtableFnPointerData<'tcx, N> {
 125     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 126         write!(f, "VtableFnPointer(fn_ty={:?}, nested={:?})",
 127                self.fn_ty,
 128                self.nested)
 129     }
 130 }
 131
 132 impl<'tcx> fmt::Debug for traits::FulfillmentError<'tcx> {
 133     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 134         write!(f, "FulfillmentError({:?},{:?})",
 135                self.obligation,
 136                self.code)
 137     }
 138 }
 139
 140 impl<'tcx> fmt::Debug for traits::FulfillmentErrorCode<'tcx> {
 141     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 142         match *self {
 143             super::CodeSelectionError(ref e) => write!(f, "{:?}", e),
 144             super::CodeProjectionError(ref e) => write!(f, "{:?}", e),
 145             super::CodeSubtypeError(ref a, ref b) =>
 146                 write!(f, "CodeSubtypeError({:?}, {:?})", a, b),
 147             super::CodeAmbiguity => write!(f, "Ambiguity")
 148         }
 149     }
 150 }
 151
 152 impl<'tcx> fmt::Debug for traits::MismatchedProjectionTypes<'tcx> {
 153     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 154         write!(f, "MismatchedProjectionTypes({:?})", self.err)
 155     }
 156 }
 157
 158 ///////////////////////////////////////////////////////////////////////////
 159 // Lift implementations
 160
 161 impl<'a, 'tcx> Lift<'tcx> for traits::SelectionError<'a> {
 162     type Lifted = traits::SelectionError<'tcx>;
 163     fn lift_to_tcx<'b, 'gcx>(&self, tcx: TyCtxt<'b, 'gcx, 'tcx>) -> Option<Self::Lifted> {
 164         match *self {
 165             super::Unimplemented => Some(super::Unimplemented),
 166             super::OutputTypeParameterMismatch(a, b, ref err) => {
 167                 tcx.lift(&(a, b)).and_then(|(a, b)| {
 168                     tcx.lift(err).map(|err| {
 169                         super::OutputTypeParameterMismatch(a, b, err)
 170                     })
 171                 })
 172             }
 173             super::TraitNotObjectSafe(def_id) => {
 174                 Some(super::TraitNotObjectSafe(def_id))
 175             }
 176             super::ConstEvalFailure(ref err) => {
 177                 tcx.lift(err).map(super::ConstEvalFailure)
 178             }
 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) => {
 197                 tcx.lift(&ty).and_then(|ty| {
 198                     tcx.lift(&r).and_then(|r| {
 199                         Some(super::ObjectTypeBound(ty, r))
 200                     })
 201                 })
 202             }
 203             super::ObjectCastObligation(ty) => {
 204                 tcx.lift(&ty).map(super::ObjectCastObligation)
 205             }
 206             super::AssignmentLhsSized => Some(super::AssignmentLhsSized),
 207             super::TupleInitializerSized => Some(super::TupleInitializerSized),
 208             super::StructInitializerSized => Some(super::StructInitializerSized),
 209             super::VariableType(id) => Some(super::VariableType(id)),
 210             super::ReturnType(id) => Some(super::ReturnType(id)),
 211             super::SizedReturnType => Some(super::SizedReturnType),
 212             super::SizedYieldType => Some(super::SizedYieldType),
 213             super::RepeatVec => Some(super::RepeatVec),
 214             super::FieldSized(item) => Some(super::FieldSized(item)),
 215             super::ConstSized => Some(super::ConstSized),
 216             super::SharedStatic => Some(super::SharedStatic),
 217             super::BuiltinDerivedObligation(ref cause) => {
 218                 tcx.lift(cause).map(super::BuiltinDerivedObligation)
 219             }
 220             super::ImplDerivedObligation(ref cause) => {
 221                 tcx.lift(cause).map(super::ImplDerivedObligation)
 222             }
 223             super::CompareImplMethodObligation { item_name,
 224                                                  impl_item_def_id,
 225                                                  trait_item_def_id } => {
 226                 Some(super::CompareImplMethodObligation {
 227                     item_name,
 228                     impl_item_def_id,
 229                     trait_item_def_id,
 230                 })
 231             }
 232             super::ExprAssignable => Some(super::ExprAssignable),
 233             super::MatchExpressionArm { arm_span, source } => {
 234                 Some(super::MatchExpressionArm { arm_span,
 235                                                  source: source })
 236             }
 237             super::IfExpression => Some(super::IfExpression),
 238             super::IfExpressionWithNoElse => Some(super::IfExpressionWithNoElse),
 239             super::EquatePredicate => Some(super::EquatePredicate),
 240             super::MainFunctionType => Some(super::MainFunctionType),
 241             super::StartFunctionType => Some(super::StartFunctionType),
 242             super::IntrinsicType => Some(super::IntrinsicType),
 243             super::MethodReceiver => Some(super::MethodReceiver),
 244             super::BlockTailExpression(id) => Some(super::BlockTailExpression(id)),
 245         }
 246     }
 247 }
 248
 249 impl<'a, 'tcx> Lift<'tcx> for traits::DerivedObligationCause<'a> {
 250     type Lifted = traits::DerivedObligationCause<'tcx>;
 251     fn lift_to_tcx<'b, 'gcx>(&self, tcx: TyCtxt<'b, 'gcx, 'tcx>) -> Option<Self::Lifted> {
 252         tcx.lift(&self.parent_trait_ref).and_then(|trait_ref| {
 253             tcx.lift(&*self.parent_code).map(|code| {
 254                 traits::DerivedObligationCause {
 255                     parent_trait_ref: trait_ref,
 256                     parent_code: Rc::new(code)
 257                 }
 258             })
 259         })
 260     }
 261 }
 262
 263 impl<'a, 'tcx> Lift<'tcx> for traits::ObligationCause<'a> {
 264     type Lifted = traits::ObligationCause<'tcx>;
 265     fn lift_to_tcx<'b, 'gcx>(&self, tcx: TyCtxt<'b, 'gcx, 'tcx>) -> Option<Self::Lifted> {
 266         tcx.lift(&self.code).map(|code| {
 267             traits::ObligationCause {
 268                 span: self.span,
 269                 body_id: self.body_id,
 270                 code,
 271             }
 272         })
 273     }
 274 }
 275
 276 // For trans only.
 277 impl<'a, 'tcx> Lift<'tcx> for traits::Vtable<'a, ()> {
 278     type Lifted = traits::Vtable<'tcx, ()>;
 279     fn lift_to_tcx<'b, 'gcx>(&self, tcx: TyCtxt<'b, 'gcx, 'tcx>) -> Option<Self::Lifted> {
 280         match self.clone() {
 281             traits::VtableImpl(traits::VtableImplData {
 282                 impl_def_id,
 283                 substs,
 284                 nested
 285             }) => {
 286                 tcx.lift(&substs).map(|substs| {
 287                     traits::VtableImpl(traits::VtableImplData {
 288                         impl_def_id,
 289                         substs,
 290                         nested,
 291                     })
 292                 })
 293             }
 294             traits::VtableAutoImpl(t) => Some(traits::VtableAutoImpl(t)),
 295             traits::VtableGenerator(traits::VtableGeneratorData {
 296                 closure_def_id,
 297                 substs,
 298                 nested
 299             }) => {
 300                 tcx.lift(&substs).map(|substs| {
 301                     traits::VtableGenerator(traits::VtableGeneratorData {
 302                         closure_def_id: closure_def_id,
 303                         substs: substs,
 304                         nested: nested
 305                     })
 306                 })
 307             }
 308             traits::VtableClosure(traits::VtableClosureData {
 309                 closure_def_id,
 310                 substs,
 311                 nested
 312             }) => {
 313                 tcx.lift(&substs).map(|substs| {
 314                     traits::VtableClosure(traits::VtableClosureData {
 315                         closure_def_id,
 316                         substs,
 317                         nested,
 318                     })
 319                 })
 320             }
 321             traits::VtableFnPointer(traits::VtableFnPointerData { fn_ty, nested }) => {
 322                 tcx.lift(&fn_ty).map(|fn_ty| {
 323                     traits::VtableFnPointer(traits::VtableFnPointerData {
 324                         fn_ty,
 325                         nested,
 326                     })
 327                 })
 328             }
 329             traits::VtableParam(n) => Some(traits::VtableParam(n)),
 330             traits::VtableBuiltin(n) => Some(traits::VtableBuiltin(n)),
 331             traits::VtableObject(traits::VtableObjectData {
 332                 upcast_trait_ref,
 333                 vtable_base,
 334                 nested
 335             }) => {
 336                 tcx.lift(&upcast_trait_ref).map(|trait_ref| {
 337                     traits::VtableObject(traits::VtableObjectData {
 338                         upcast_trait_ref: trait_ref,
 339                         vtable_base,
 340                         nested,
 341                     })
 342                 })
 343             }
 344         }
 345     }
 346 }
 347
 348 ///////////////////////////////////////////////////////////////////////////
 349 // TypeFoldable implementations.
 350
 351 impl<'tcx, O: TypeFoldable<'tcx>> TypeFoldable<'tcx> for traits::Obligation<'tcx, O>
 352 {
 353     fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
 354         traits::Obligation {
 355             cause: self.cause.clone(),
 356             recursion_depth: self.recursion_depth,
 357             predicate: self.predicate.fold_with(folder),
 358             param_env: self.param_env.fold_with(folder),
 359         }
 360     }
 361
 362     fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
 363         self.predicate.visit_with(visitor)
 364     }
 365 }
 366
 367 impl<'tcx, N: TypeFoldable<'tcx>> TypeFoldable<'tcx> for traits::VtableImplData<'tcx, N> {
 368     fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
 369         traits::VtableImplData {
 370             impl_def_id: self.impl_def_id,
 371             substs: self.substs.fold_with(folder),
 372             nested: self.nested.fold_with(folder),
 373         }
 374     }
 375
 376     fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
 377         self.substs.visit_with(visitor) || self.nested.visit_with(visitor)
 378     }
 379 }
 380
 381 impl<'tcx, N: TypeFoldable<'tcx>> TypeFoldable<'tcx> for traits::VtableGeneratorData<'tcx, N> {
 382     fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
 383         traits::VtableGeneratorData {
 384             closure_def_id: self.closure_def_id,
 385             substs: self.substs.fold_with(folder),
 386             nested: self.nested.fold_with(folder),
 387         }
 388     }
 389
 390     fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
 391         self.substs.visit_with(visitor) || self.nested.visit_with(visitor)
 392     }
 393 }
 394
 395 impl<'tcx, N: TypeFoldable<'tcx>> TypeFoldable<'tcx> for traits::VtableClosureData<'tcx, N> {
 396     fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
 397         traits::VtableClosureData {
 398             closure_def_id: self.closure_def_id,
 399             substs: self.substs.fold_with(folder),
 400             nested: self.nested.fold_with(folder),
 401         }
 402     }
 403
 404     fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
 405         self.substs.visit_with(visitor) || self.nested.visit_with(visitor)
 406     }
 407 }
 408
 409 impl<'tcx, N: TypeFoldable<'tcx>> TypeFoldable<'tcx> for traits::VtableAutoImplData<N> {
 410     fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
 411         traits::VtableAutoImplData {
 412             trait_def_id: self.trait_def_id,
 413             nested: self.nested.fold_with(folder),
 414         }
 415     }
 416
 417     fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
 418         self.nested.visit_with(visitor)
 419     }
 420 }
 421
 422 impl<'tcx, N: TypeFoldable<'tcx>> TypeFoldable<'tcx> for traits::VtableBuiltinData<N> {
 423     fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
 424         traits::VtableBuiltinData {
 425             nested: self.nested.fold_with(folder),
 426         }
 427     }
 428
 429     fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
 430         self.nested.visit_with(visitor)
 431     }
 432 }
 433
 434 impl<'tcx, N: TypeFoldable<'tcx>> TypeFoldable<'tcx> for traits::VtableObjectData<'tcx, N> {
 435     fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
 436         traits::VtableObjectData {
 437             upcast_trait_ref: self.upcast_trait_ref.fold_with(folder),
 438             vtable_base: self.vtable_base,
 439             nested: self.nested.fold_with(folder),
 440         }
 441     }
 442
 443     fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
 444         self.upcast_trait_ref.visit_with(visitor) || self.nested.visit_with(visitor)
 445     }
 446 }
 447
 448 impl<'tcx, N: TypeFoldable<'tcx>> TypeFoldable<'tcx> for traits::VtableFnPointerData<'tcx, N> {
 449     fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
 450         traits::VtableFnPointerData {
 451             fn_ty: self.fn_ty.fold_with(folder),
 452             nested: self.nested.fold_with(folder),
 453         }
 454     }
 455
 456     fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
 457         self.fn_ty.visit_with(visitor) || self.nested.visit_with(visitor)
 458     }
 459 }
 460
 461 impl<'tcx, N: TypeFoldable<'tcx>> TypeFoldable<'tcx> for traits::Vtable<'tcx, N> {
 462     fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
 463         match *self {
 464             traits::VtableImpl(ref v) => traits::VtableImpl(v.fold_with(folder)),
 465             traits::VtableAutoImpl(ref t) => traits::VtableAutoImpl(t.fold_with(folder)),
 466             traits::VtableGenerator(ref d) => {
 467                 traits::VtableGenerator(d.fold_with(folder))
 468             }
 469             traits::VtableClosure(ref d) => {
 470                 traits::VtableClosure(d.fold_with(folder))
 471             }
 472             traits::VtableFnPointer(ref d) => {
 473                 traits::VtableFnPointer(d.fold_with(folder))
 474             }
 475             traits::VtableParam(ref n) => traits::VtableParam(n.fold_with(folder)),
 476             traits::VtableBuiltin(ref d) => traits::VtableBuiltin(d.fold_with(folder)),
 477             traits::VtableObject(ref d) => traits::VtableObject(d.fold_with(folder)),
 478         }
 479     }
 480
 481     fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
 482         match *self {
 483             traits::VtableImpl(ref v) => v.visit_with(visitor),
 484             traits::VtableAutoImpl(ref t) => t.visit_with(visitor),
 485             traits::VtableGenerator(ref d) => d.visit_with(visitor),
 486             traits::VtableClosure(ref d) => d.visit_with(visitor),
 487             traits::VtableFnPointer(ref d) => d.visit_with(visitor),
 488             traits::VtableParam(ref n) => n.visit_with(visitor),
 489             traits::VtableBuiltin(ref d) => d.visit_with(visitor),
 490             traits::VtableObject(ref d) => d.visit_with(visitor),
 491         }
 492     }
 493 }
 494
 495 impl<'tcx, T: TypeFoldable<'tcx>> TypeFoldable<'tcx> for Normalized<'tcx, T> {
 496     fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
 497         Normalized {
 498             value: self.value.fold_with(folder),
 499             obligations: self.obligations.fold_with(folder),
 500         }
 501     }
 502
 503     fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
 504         self.value.visit_with(visitor) || self.obligations.visit_with(visitor)
 505     }
 506 }
 507
 508 impl<'tcx> TypeFoldable<'tcx> for traits::ObligationCauseCode<'tcx> {
 509     fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
 510         match *self {
 511             super::ExprAssignable |
 512             super::MatchExpressionArm { arm_span: _, source: _ } |
 513             super::IfExpression |
 514             super::IfExpressionWithNoElse |
 515             super::EquatePredicate |
 516             super::MainFunctionType |
 517             super::StartFunctionType |
 518             super::IntrinsicType |
 519             super::MethodReceiver |
 520             super::MiscObligation |
 521             super::SliceOrArrayElem |
 522             super::TupleElem |
 523             super::ItemObligation(_) |
 524             super::AssignmentLhsSized |
 525             super::TupleInitializerSized |
 526             super::StructInitializerSized |
 527             super::VariableType(_) |
 528             super::ReturnType(_) |
 529             super::SizedReturnType |
 530             super::SizedYieldType |
 531             super::ReturnNoExpression |
 532             super::RepeatVec |
 533             super::FieldSized(_) |
 534             super::ConstSized |
 535             super::SharedStatic |
 536             super::BlockTailExpression(_) |
 537             super::CompareImplMethodObligation { .. } => self.clone(),
 538
 539             super::ProjectionWf(proj) => super::ProjectionWf(proj.fold_with(folder)),
 540             super::ReferenceOutlivesReferent(ty) => {
 541                 super::ReferenceOutlivesReferent(ty.fold_with(folder))
 542             }
 543             super::ObjectTypeBound(ty, r) => {
 544                 super::ObjectTypeBound(ty.fold_with(folder), r.fold_with(folder))
 545             }
 546             super::ObjectCastObligation(ty) => {
 547                 super::ObjectCastObligation(ty.fold_with(folder))
 548             }
 549             super::BuiltinDerivedObligation(ref cause) => {
 550                 super::BuiltinDerivedObligation(cause.fold_with(folder))
 551             }
 552             super::ImplDerivedObligation(ref cause) => {
 553                 super::ImplDerivedObligation(cause.fold_with(folder))
 554             }
 555         }
 556     }
 557
 558     fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
 559         match *self {
 560             super::ExprAssignable |
 561             super::MatchExpressionArm { arm_span: _, source: _ } |
 562             super::IfExpression |
 563             super::IfExpressionWithNoElse |
 564             super::EquatePredicate |
 565             super::MainFunctionType |
 566             super::StartFunctionType |
 567             super::IntrinsicType |
 568             super::MethodReceiver |
 569             super::MiscObligation |
 570             super::SliceOrArrayElem |
 571             super::TupleElem |
 572             super::ItemObligation(_) |
 573             super::AssignmentLhsSized |
 574             super::TupleInitializerSized |
 575             super::StructInitializerSized |
 576             super::VariableType(_) |
 577             super::ReturnType(_) |
 578             super::SizedReturnType |
 579             super::SizedYieldType |
 580             super::ReturnNoExpression |
 581             super::RepeatVec |
 582             super::FieldSized(_) |
 583             super::ConstSized |
 584             super::SharedStatic |
 585             super::BlockTailExpression(_) |
 586             super::CompareImplMethodObligation { .. } => false,
 587
 588             super::ProjectionWf(proj) => proj.visit_with(visitor),
 589             super::ReferenceOutlivesReferent(ty) => ty.visit_with(visitor),
 590             super::ObjectTypeBound(ty, r) => ty.visit_with(visitor) || r.visit_with(visitor),
 591             super::ObjectCastObligation(ty) => ty.visit_with(visitor),
 592             super::BuiltinDerivedObligation(ref cause) => cause.visit_with(visitor),
 593             super::ImplDerivedObligation(ref cause) => cause.visit_with(visitor)
 594         }
 595     }
 596 }
 597
 598 impl<'tcx> TypeFoldable<'tcx> for traits::DerivedObligationCause<'tcx> {
 599     fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
 600         traits::DerivedObligationCause {
 601             parent_trait_ref: self.parent_trait_ref.fold_with(folder),
 602             parent_code: self.parent_code.fold_with(folder)
 603         }
 604     }
 605
 606     fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
 607         self.parent_trait_ref.visit_with(visitor) || self.parent_code.visit_with(visitor)
 608     }
 609 }
 610
 611 impl<'tcx> TypeFoldable<'tcx> for traits::ObligationCause<'tcx> {
 612     fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
 613         traits::ObligationCause {
 614             span: self.span,
 615             body_id: self.body_id,
 616             code: self.code.fold_with(folder),
 617         }
 618     }
 619
 620     fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
 621         self.code.visit_with(visitor)
 622     }
 623 }