Merge pull request swiftlang#29713 from CodaFi/unused-unwanted-unloved

CodaFi · web-flow · commit 054d7b991322 · 2020-02-11T15:46:16.000-08:00
[Gardening] Silence Some Warning Spew
diff --git a/include/swift/SIL/AbstractionPattern.h b/include/swift/SIL/AbstractionPattern.h
@@ -675,7 +675,7 @@ class AbstractionPattern {
           isa<GenericTypeParamType>(type)) {
         return true;
       }
-      if (auto archetype = dyn_cast<ArchetypeType>(type)) {
+      if (isa<ArchetypeType>(type)) {
         return true;
       }
       return false;
diff --git a/lib/AST/ASTDumper.cpp b/lib/AST/ASTDumper.cpp
@@ -716,7 +716,7 @@ namespace {
 
       if (auto *var = dyn_cast<VarDecl>(VD)) {
         PrintWithColorRAII(OS, TypeColor) << " type='";
-        if (auto varTy = var->hasInterfaceType())
+        if (var->hasInterfaceType())
           var->getType().print(PrintWithColorRAII(OS, TypeColor).getOS());
         else
           PrintWithColorRAII(OS, TypeColor) << "<null type>";
diff --git a/lib/AST/ASTScopeCreation.cpp b/lib/AST/ASTScopeCreation.cpp
@@ -523,7 +523,7 @@ class ScopeCreator final {
           // get inactive nodes that nest in active clauses
           for (auto n : clause.Elements) {
             if (auto *const d = n.dyn_cast<Decl *>())
-              if (auto *const icd = dyn_cast<IfConfigDecl>(d))
+              if (isa<IfConfigDecl>(d))
                 expandIfConfigClausesInto(expansion, {d}, true);
           }
         } else if (includeInactiveIfConfigClauses) {
@@ -1776,7 +1776,7 @@ void ScopeCreator::forEachClosureIn(
       return {true, E};
     }
     std::pair<bool, Stmt *> walkToStmtPre(Stmt *S) override {
-      if (auto *bs = dyn_cast<BraceStmt>(S)) { // closures hidden in here
+      if (isa<BraceStmt>(S)) { // closures hidden in here
         return {true, S};
       }
       return {false, S};
@@ -2132,7 +2132,7 @@ class LocalizableDeclContextCollector : public ASTWalker {
     auto f = SM.getIdentifierForBuffer(bufID);
     auto lin = SM.getLineNumber(loc);
     if (f.endswith(file) && lin == line)
-      if (auto *v = dyn_cast<PatternBindingDecl>(D))
+      if (isa<PatternBindingDecl>(D))
         llvm::errs() << "*** catchForDebugging: " << lin << " ***\n";
   }
 };
diff --git a/lib/AST/AccessRequests.cpp b/lib/AST/AccessRequests.cpp
@@ -68,7 +68,7 @@ AccessLevelRequest::evaluate(Evaluator &evaluator, ValueDecl *D) const {
 
   // Special case for generic parameters; we just give them a dummy
   // access level.
-  if (auto genericParam = dyn_cast<GenericTypeParamDecl>(D)) {
+  if (isa<GenericTypeParamDecl>(D)) {
     return AccessLevel::Internal;
   }
 
@@ -213,7 +213,7 @@ DefaultAndMaxAccessLevelRequest::evaluate(Evaluator &evaluator,
 
   AccessLevel maxAccess = AccessLevel::Public;
 
-  if (GenericParamList *genericParams = ED->getGenericParams()) {
+  if (ED->getGenericParams()) {
     // Only check the trailing 'where' requirements. Other requirements come
     // from the extended type and have already been checked.
     DirectlyReferencedTypeDecls typeDecls =
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
@@ -645,7 +645,7 @@ Expr *AbstractFunctionDecl::getSingleExpressionBody() const {
   if (auto *stmt = body.dyn_cast<Stmt *>()) {
     if (auto *returnStmt = dyn_cast<ReturnStmt>(stmt)) {
       return returnStmt->getResult();
-    } else if (auto *failStmt = dyn_cast<FailStmt>(stmt)) {
+    } else if (isa<FailStmt>(stmt)) {
       // We can only get to this point if we're a type-checked ConstructorDecl
       // which was originally spelled init?(...) { nil }.  
       //
@@ -663,7 +663,7 @@ void AbstractFunctionDecl::setSingleExpressionBody(Expr *NewBody) {
     if (auto *returnStmt = dyn_cast<ReturnStmt>(stmt)) {
       returnStmt->setResult(NewBody);
       return;
-    } else if (auto *failStmt = dyn_cast<FailStmt>(stmt)) {
+    } else if (isa<FailStmt>(stmt)) {
       // We can only get to this point if we're a type-checked ConstructorDecl
       // which was originally spelled init?(...) { nil }.  
       //
@@ -780,7 +780,7 @@ bool Decl::isPrivateStdlibDecl(bool treatNonBuiltinProtocolsAsPublic) const {
       FU->getKind() != FileUnitKind::SerializedAST)
     return false;
 
-  if (auto PD = dyn_cast<ProtocolDecl>(D)) {
+  if (isa<ProtocolDecl>(D)) {
     if (treatNonBuiltinProtocolsAsPublic)
       return false;
   }
@@ -2657,7 +2657,7 @@ static Type mapSignatureFunctionType(ASTContext &ctx, Type type,
     
     // Functions and subscripts cannot overload differing only in opaque return
     // types. Replace the opaque type with `Any`.
-    if (auto opaque = type->getAs<OpaqueTypeArchetypeType>()) {
+    if (type->is<OpaqueTypeArchetypeType>()) {
       type = ProtocolCompositionType::get(ctx, {}, /*hasAnyObject*/ false);
     }
 
diff --git a/lib/AST/IndexSubset.cpp b/lib/AST/IndexSubset.cpp
@@ -16,7 +16,6 @@ using namespace swift;
 
 IndexSubset *
 IndexSubset::getFromString(ASTContext &ctx, StringRef string) {
-  if (string.size() < 0) return nullptr;
   unsigned capacity = string.size();
   llvm::SmallBitVector indices(capacity);
   for (unsigned i : range(capacity)) {
diff --git a/lib/AST/Module.cpp b/lib/AST/Module.cpp
@@ -1218,7 +1218,7 @@ ModuleDecl::ReverseFullNameIterator::operator++() {
   if (!current)
     return *this;
 
-  if (auto *swiftModule = current.dyn_cast<const ModuleDecl *>()) {
+  if (current.is<const ModuleDecl *>()) {
     current = nullptr;
     return *this;
   }
diff --git a/lib/AST/Type.cpp b/lib/AST/Type.cpp
@@ -2023,7 +2023,7 @@ getObjCObjectRepresentable(Type type, const DeclContext *dc) {
   // DynamicSelfType is always representable in Objective-C, even if
   // the class is not @objc, allowing Self-returning methods to witness
   // @objc protocol requirements.
-  if (auto dynSelf = type->getAs<DynamicSelfType>())
+  if (type->is<DynamicSelfType>())
     return ForeignRepresentableKind::Object;
 
   // @objc classes.
@@ -3442,7 +3442,7 @@ Type DependentMemberType::substBaseType(Type substBase,
 Type DependentMemberType::substRootParam(Type newRoot,
                                          LookupConformanceFn lookupConformance){
   auto base = getBase();
-  if (auto param = base->getAs<GenericTypeParamType>()) {
+  if (base->is<GenericTypeParamType>()) {
     return substBaseType(newRoot, lookupConformance);
   }
   if (auto depMem = base->getAs<DependentMemberType>()) {
@@ -3633,7 +3633,7 @@ static Type substType(Type derivedType,
     if (isa<GenericTypeParamType>(substOrig))
       return ErrorType::get(type);
 
-    if (auto primaryArchetype = dyn_cast<PrimaryArchetypeType>(substOrig))
+    if (isa<PrimaryArchetypeType>(substOrig))
       return ErrorType::get(type);
 
     // Opened existentials cannot be substituted in this manner,
@@ -4098,7 +4098,7 @@ case TypeKind::Id:
     auto fnTy = cast<SILFunctionType>(base);
     bool changed = false;
     
-    if (auto subs = fnTy->getSubstitutions()) {
+    if (fnTy->getSubstitutions()) {
 #ifndef NDEBUG
       // This interface isn't suitable for updating the substitution map in a
       // substituted SILFunctionType.
diff --git a/lib/AST/TypeCheckRequests.cpp b/lib/AST/TypeCheckRequests.cpp
@@ -363,7 +363,7 @@ SourceLoc WhereClauseOwner::getLoc() const {
 
 void swift::simple_display(llvm::raw_ostream &out,
                            const WhereClauseOwner &owner) {
-  if (auto where = owner.source.dyn_cast<TrailingWhereClause *>()) {
+  if (owner.source.is<TrailingWhereClause *>()) {
     simple_display(out, owner.dc->getAsDecl());
   } else if (owner.source.is<SpecializeAttr *>()) {
     out << "@_specialize";
diff --git a/lib/Driver/Driver.cpp b/lib/Driver/Driver.cpp
@@ -2347,7 +2347,7 @@ static StringRef baseNameForImage(const JobAction *JA, const OutputInfo &OI,
   if (JA->size() == 1 && OI.ModuleNameIsFallback && BaseInput != "-")
     return llvm::sys::path::stem(BaseInput);
   
-  if (auto link = dyn_cast<StaticLinkJobAction>(JA)) {
+  if (isa<StaticLinkJobAction>(JA)) {
     Buffer = "lib";
     Buffer.append(BaseName);
     Buffer.append(Triple.isOSWindows() ? ".lib" : ".a");
diff --git a/lib/Driver/DriverIncrementalRanges.cpp b/lib/Driver/DriverIncrementalRanges.cpp
@@ -84,10 +84,14 @@ Optional<SourceRangeBasedInfo> SourceRangeBasedInfo::loadInfoForOnePrimary(
     DiagnosticEngine &diags) {
 
   auto removeSupplementaryPaths = [&] {
-    if (auto ec = llvm::sys::fs::remove(compiledSourcePath))
+    if (auto ec = llvm::sys::fs::remove(compiledSourcePath)) {
+      (void)ec;
       llvm::errs() << "WARNING could not remove: " << compiledSourcePath;
-    if (auto ec = llvm::sys::fs::remove(swiftRangesPath))
+    }
+    if (auto ec = llvm::sys::fs::remove(swiftRangesPath)) {
+      (void)ec;
       llvm::errs() << "WARNING could not remove: " << swiftRangesPath;
+    }
   };
 
   assert(!primaryInputPath.empty() && "Must have a primary to load info.");
diff --git a/lib/IDE/CodeCompletion.cpp b/lib/IDE/CodeCompletion.cpp
@@ -5239,7 +5239,7 @@ void CodeCompletionCallbacksImpl::doneParsing() {
   }
   if (auto *DRE = dyn_cast_or_null<DeclRefExpr>(ParsedExpr)) {
     Lookup.setIsSelfRefExpr(DRE->getDecl()->getFullName() == Context.Id_self);
-  } else if (auto *SRE = dyn_cast_or_null<SuperRefExpr>(ParsedExpr)) {
+  } else if (ParsedExpr && isa<SuperRefExpr>(ParsedExpr)) {
     Lookup.setIsSuperRefExpr();
   }
 
diff --git a/lib/IRGen/GenType.cpp b/lib/IRGen/GenType.cpp
@@ -440,7 +440,7 @@ static void emitSpecializedMemOperation(
   auto &Builder = IGF.Builder;
 
   // Sizes to try. Tested in order.
-  const auto sizes = std::array<Size, 4>{
+  const std::array<Size, 4> sizes = {
     Size(0),
     Size(1),
     Size(2),
diff --git a/lib/IRGen/IRGenMangler.cpp b/lib/IRGen/IRGenMangler.cpp
@@ -120,7 +120,7 @@ IRGenMangler::withSymbolicReferences(IRGenModule &IGM,
       }
 
       return true;
-    } else if (auto opaque = s.dyn_cast<const OpaqueTypeDecl *>()) {
+    } else if (s.is<const OpaqueTypeDecl *>()) {
       // Always symbolically reference opaque types.
       return true;
     } else {
diff --git a/lib/IRGen/MetadataRequest.cpp b/lib/IRGen/MetadataRequest.cpp
@@ -1936,7 +1936,7 @@ MetadataResponse irgen::emitGenericTypeMetadataAccessFunction(
       ? IGF.Builder.CreateBitCast(params.claimNext(), IGM.Int8PtrTy)
       : llvm::UndefValue::get(IGM.Int8PtrTy);
 
-    std::array<llvm::Value *, 3> argValues{arg0, arg1, arg2};
+    std::array<llvm::Value *, 3> argValues = {arg0, arg1, arg2};
 
     emitCanonicalSpecializationsForGenericTypeMetadataAccessFunction(
         IGF, params, nominal, genericArgs,
diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
@@ -6397,7 +6397,7 @@ void Parser::parseAbstractFunctionBody(AbstractFunctionDecl *AFD) {
             return;
           }
         }
-        if (auto F = dyn_cast<FuncDecl>(AFD)) {
+        if (isa<FuncDecl>(AFD)) {
           auto RS = new (Context) ReturnStmt(SourceLoc(), E);
           BS->setFirstElement(RS);
           AFD->setHasSingleExpressionBody();
diff --git a/lib/SIL/LinearLifetimeChecker.cpp b/lib/SIL/LinearLifetimeChecker.cpp
@@ -219,7 +219,7 @@ void State::initializeConsumingUse(BranchPropagatedUser consumingUser,
     llvm::errs() << "Function: '" << beginBlock->getParent()->getName() << "'\n"
                  << "Found over consume?!\n";
     if (auto v = value) {
-      llvm::errs() << "Value: " << *value;
+      llvm::errs() << "Value: " << *v;
     } else {
       llvm::errs() << "Value: N/A\n";
     }
diff --git a/lib/SILOptimizer/Transforms/CopyPropagation.cpp b/lib/SILOptimizer/Transforms/CopyPropagation.cpp
@@ -615,7 +615,7 @@ static bool computeLiveness(CopyPropagationState &pass) {
       // point of the end_borrow.
       if (auto *BBI = dyn_cast<BeginBorrowInst>(user)) {
         for (Operand *use : BBI->getUses()) {
-          if (auto *EBI = dyn_cast<EndBorrowInst>(use->getUser()))
+          if (isa<EndBorrowInst>(use->getUser()))
             computeUseLiveness(use, pass);
         }
         continue;
diff --git a/lib/Sema/BuilderTransform.cpp b/lib/Sema/BuilderTransform.cpp
@@ -266,7 +266,7 @@ class BuilderClosureVisitor
           continue;
 
         // Skip #warning/#error; we'll handle them when applying the builder.
-        if (auto poundDiag = dyn_cast<PoundDiagnosticDecl>(decl)) {
+        if (isa<PoundDiagnosticDecl>(decl)) {
           continue;
         }
 
diff --git a/lib/Sema/CSBindings.cpp b/lib/Sema/CSBindings.cpp
@@ -904,7 +904,7 @@ Optional<Type> ConstraintSystem::checkTypeOfBinding(TypeVariableType *typeVar,
   }
 
   // If the type is a type variable itself, don't permit the binding.
-  if (auto *bindingTypeVar = type->getRValueType()->getAs<TypeVariableType>())
+  if (type->getRValueType()->is<TypeVariableType>())
     return None;
 
   // Don't bind to a dependent member type, even if it's currently
@@ -1082,8 +1082,8 @@ bool TypeVariableBinding::attempt(ConstraintSystem &cs) const {
             cs, TypeVar->getImpl().getLocator());
         if (cs.recordFix(fix))
           return true;
-      } else if (auto *OLE = dyn_cast_or_null<ObjectLiteralExpr>(
-                     srcLocator->getAnchor())) {
+      } else if (srcLocator->getAnchor() &&
+                 isa<ObjectLiteralExpr>(srcLocator->getAnchor())) {
         auto *fix = SpecifyObjectLiteralTypeImport::create(
             cs, TypeVar->getImpl().getLocator());
         if (cs.recordFix(fix))
diff --git a/lib/Sema/CSDiag.cpp b/lib/Sema/CSDiag.cpp
@@ -1242,8 +1242,8 @@ void FailureDiagnosis::diagnoseAmbiguity(Expr *E) {
   // Unresolved/Anonymous ClosureExprs are common enough that we should give
   // them tailored diagnostics.
   if (auto CE = dyn_cast<ClosureExpr>(E->getValueProvidingExpr())) {
-    diagnose(E->getLoc(), diag::cannot_infer_closure_type)
-      .highlight(E->getSourceRange());
+    diagnose(CE->getLoc(), diag::cannot_infer_closure_type)
+      .highlight(CE->getSourceRange());
     return;
   }
 
diff --git a/lib/Sema/CSDiagnostics.cpp b/lib/Sema/CSDiagnostics.cpp
@@ -728,7 +728,7 @@ bool LabelingFailure::diagnoseAsNote() {
     return false;
 
   SmallVector<Identifier, 4> argLabels;
-  if (auto *paren = dyn_cast<ParenExpr>(argExpr)) {
+  if (isa<ParenExpr>(argExpr)) {
     argLabels.push_back(Identifier());
   } else if (auto *tuple = dyn_cast<TupleExpr>(argExpr)) {
     argLabels.append(tuple->getElementNames().begin(),
@@ -1304,7 +1304,7 @@ bool RValueTreatedAsLValueFailure::diagnoseAsError() {
               diag::assignment_dynamic_property_has_immutable_base;
       }
     }
-  } else if (auto sub = dyn_cast<SubscriptExpr>(diagExpr)) {
+  } else if (isa<SubscriptExpr>(diagExpr)) {
       subElementDiagID = diag::assignment_subscript_has_immutable_base;
   } else {
     subElementDiagID = diag::assignment_lhs_is_immutable_variable;
@@ -2169,7 +2169,7 @@ bool ContextualFailure::diagnoseConversionToNil() const {
       if (auto *TE = dyn_cast<TupleExpr>(parentExpr)) {
         // In case of dictionary e.g. `[42: nil]` we need to figure
         // out whether nil is a "key" or a "value".
-        if (auto *DE = dyn_cast<DictionaryExpr>(enclosingExpr)) {
+        if (isa<DictionaryExpr>(enclosingExpr)) {
           assert(TE->getNumElements() == 2);
           CTP = TE->getElement(0) == anchor ? CTP_DictionaryKey
                                             : CTP_DictionaryValue;
@@ -2185,7 +2185,7 @@ bool ContextualFailure::diagnoseConversionToNil() const {
       if (isa<ApplyExpr>(enclosingExpr) || isa<SubscriptExpr>(enclosingExpr) ||
           isa<KeyPathExpr>(enclosingExpr))
         CTP = CTP_CallArgument;
-    } else if (auto *CE = dyn_cast<CoerceExpr>(parentExpr)) {
+    } else if (isa<CoerceExpr>(parentExpr)) {
       // `nil` is passed as a left-hand side of the coercion
       // operator e.g. `nil as Foo`
       CTP = CTP_CoerceOperand;
@@ -3601,10 +3601,10 @@ bool AllowTypeOrInstanceMemberFailure::diagnoseAsError() {
         // Give a customized message if we're accessing a member type
         // of a protocol -- otherwise a diagnostic talking about
         // static members doesn't make a whole lot of sense
-        if (auto TAD = dyn_cast<TypeAliasDecl>(Member)) {
+        if (isa<TypeAliasDecl>(Member)) {
           Diag.emplace(emitDiagnostic(loc, diag::typealias_outside_of_protocol,
                                       Name));
-        } else if (auto ATD = dyn_cast<AssociatedTypeDecl>(Member)) {
+        } else if (isa<AssociatedTypeDecl>(Member)) {
           Diag.emplace(emitDiagnostic(loc, diag::assoc_type_outside_of_protocol,
                                       Name));
         } else if (isa<ConstructorDecl>(Member)) {
diff --git a/lib/Sema/ConstraintSystem.cpp b/lib/Sema/ConstraintSystem.cpp
@@ -2355,7 +2355,7 @@ void ConstraintSystem::resolveOverload(ConstraintLocator *locator,
       }
     }
 
-    if (auto *SD = dyn_cast<SubscriptDecl>(decl)) {
+    if (isa<SubscriptDecl>(decl)) {
       if (locator->isResultOfKeyPathDynamicMemberLookup() ||
           locator->isKeyPathSubscriptComponent()) {
         // Subscript type has a format of (Self[.Type) -> (Arg...) -> Result
diff --git a/lib/Sema/TypeCheckAttr.cpp b/lib/Sema/TypeCheckAttr.cpp
@@ -2931,7 +2931,7 @@ DynamicallyReplacedDeclRequest::evaluate(Evaluator &evaluator,
 
   // If we can lazily resolve the function, do so now.
   if (auto *LazyResolver = attr->Resolver) {
-    auto decl = attr->Resolver->loadDynamicallyReplacedFunctionDecl(
+    auto decl = LazyResolver->loadDynamicallyReplacedFunctionDecl(
         attr, attr->ResolverContextData);
     attr->Resolver = nullptr;
     return decl;
@@ -3891,7 +3891,7 @@ llvm::Expected<IndexSubset *> DifferentiableAttributeTypeCheckRequest::evaluate(
     // TODO(TF-654): Class initializers are not yet supported.
     // Extra JVP/VJP type calculation logic is necessary because classes have
     // both allocators and initializers.
-    if (auto *initDecl = dyn_cast<ConstructorDecl>(original)) {
+    if (isa<ConstructorDecl>(original)) {
       diags.diagnose(attr->getLocation(),
                      diag::differentiable_attr_class_init_not_yet_supported);
       attr->setInvalid();
diff --git a/lib/Sema/TypeCheckDecl.cpp b/lib/Sema/TypeCheckDecl.cpp
@@ -578,7 +578,7 @@ IsFinalRequest::evaluate(Evaluator &evaluator, ValueDecl *decl) const {
           VD->getOriginalWrappedProperty(PropertyWrapperSynthesizedPropertyKind::Backing))
         return true;
 
-      if (auto *nominalDecl = VD->getDeclContext()->getSelfClassDecl()) {
+      if (VD->getDeclContext()->getSelfClassDecl()) {
         // If this variable is a class member, mark it final if the
         // class is final, or if it was declared with 'let'.
         auto *PBD = VD->getParentPatternBinding();
diff --git a/lib/Sema/TypeCheckDeclObjC.cpp b/lib/Sema/TypeCheckDeclObjC.cpp
@@ -1043,8 +1043,7 @@ Optional<ObjCReason> shouldMarkAsObjC(const ValueDecl *VD, bool allowImplicit) {
 
   // Infer @objc for @_dynamicReplacement(for:) when replaced decl is @objc.
   if (isa<AbstractFunctionDecl>(VD) || isa<AbstractStorageDecl>(VD))
-    if (auto *replacementAttr =
-            VD->getAttrs().getAttribute<DynamicReplacementAttr>()) {
+    if (VD->getAttrs().hasAttribute<DynamicReplacementAttr>()) {
       if (auto *replaced = VD->getDynamicallyReplacedDecl()) {
         if (replaced->isObjC())
           return ObjCReason(ObjCReason::ImplicitlyObjC);
diff --git a/lib/Sema/TypeCheckPattern.cpp b/lib/Sema/TypeCheckPattern.cpp
diff --git a/lib/Sema/TypeCheckPropertyWrapper.cpp b/lib/Sema/TypeCheckPropertyWrapper.cpp
diff --git a/lib/Sema/TypeCheckProtocol.cpp b/lib/Sema/TypeCheckProtocol.cpp
diff --git a/lib/Sema/TypeCheckStorage.cpp b/lib/Sema/TypeCheckStorage.cpp
diff --git a/stdlib/public/Reflection/TypeLowering.cpp b/stdlib/public/Reflection/TypeLowering.cpp

Original file line number	Diff line number	Diff line change
`@@ -675,7 +675,7 @@ class AbstractionPattern {`
`675`	`675`	`isa<GenericTypeParamType>(type)) {`
`676`	`676`	`return true;`
`677`	`677`	`}`
`678`		`- if (auto archetype = dyn_cast<ArchetypeType>(type)) {`
	`678`	`+ if (isa<ArchetypeType>(type)) {`
`679`	`679`	`return true;`
`680`	`680`	`}`
`681`	`681`	`return false;`
Original file line number	Diff line number	Diff line change
`@@ -1218,7 +1218,7 @@ ModuleDecl::ReverseFullNameIterator::operator++() {`
`1218`	`1218`	`if (!current)`
`1219`	`1219`	`return *this;`
`1220`	`1220`
`1221`		`- if (auto swiftModule = current.dyn_cast<const ModuleDecl >()) {`
	`1221`	`+ if (current.is<const ModuleDecl *>()) {`
`1222`	`1222`	`current = nullptr;`
`1223`	`1223`	`return *this;`
`1224`	`1224`	`}`