Refactor Resolution class

1 files changed, 196 insertions, 194 deletions

diff --git a/gcc/rust/analysis/rust-resolution.h b/gcc/rust/analysis/rust-resolution.h
index 44b5db5..ee1c692 100644
--- a/gcc/rust/analysis/rust-resolution.h
+++ b/gcc/rust/analysis/rust-resolution.h
@@ -9,224 +9,226 @@
 namespace Rust {
 namespace Analysis {
 
-class TypeResolution : public AST::ASTVisitor
+class Resolution : public AST::ASTVisitor
 {
 public:
-  static bool ResolveNamesAndTypes (AST::Crate &crate, TopLevelScan &toplevel);
-
-  ~TypeResolution ();
+  ~Resolution (){};
 
   // visitor impl
   // rust-ast.h
   // virtual void visit(AttrInput& attr_input);
   // virtual void visit(TokenTree& token_tree);
   // virtual void visit(MacroMatch& macro_match);
-  virtual void visit (AST::Token &tok);
-  virtual void visit (AST::DelimTokenTree &delim_tok_tree);
-  virtual void visit (AST::AttrInputMetaItemContainer &input);
-  // virtual void visit(MetaItem& meta_item);
-  // virtual void vsit(Stmt& stmt);
-  // virtual void visit(Expr& expr);
-  virtual void visit (AST::IdentifierExpr &ident_expr);
-  // virtual void visit(Pattern& pattern);
-  // virtual void visit(Type& type);
-  // virtual void visit(TypeParamBound& type_param_bound);
-  virtual void visit (AST::Lifetime &lifetime);
-  // virtual void visit(GenericParam& generic_param);
-  virtual void visit (AST::LifetimeParam &lifetime_param);
-  // virtual void visit(TraitItem& trait_item);
-  // virtual void visit(InherentImplItem& inherent_impl_item);
-  // virtual void visit(TraitImplItem& trait_impl_item);
-  virtual void visit (AST::MacroInvocationSemi &macro);
+  virtual void visit (AST::Token &tok) = 0;
+  virtual void visit (AST::DelimTokenTree &delim_tok_tree) = 0;
+  virtual void visit (AST::AttrInputMetaItemContainer &input) = 0;
+  // virtual void visit(MetaItem& meta_item) = 0;
+  // virtual void vsit(Stmt& stmt) = 0;
+  // virtual void visit(Expr& expr) = 0;
+  virtual void visit (AST::IdentifierExpr &ident_expr) = 0;
+  // virtual void visit(Pattern& pattern) = 0;
+  // virtual void visit(Type& type) = 0;
+  // virtual void visit(TypeParamBound& type_param_bound) = 0;
+  virtual void visit (AST::Lifetime &lifetime) = 0;
+  // virtual void visit(GenericParam& generic_param) = 0;
+  virtual void visit (AST::LifetimeParam &lifetime_param) = 0;
+  // virtual void visit(TraitItem& trait_item) = 0;
+  // virtual void visit(InherentImplItem& inherent_impl_item) = 0;
+  // virtual void visit(TraitImplItem& trait_impl_item) = 0;
+  virtual void visit (AST::MacroInvocationSemi &macro) = 0;
 
   // rust-path.h
-  virtual void visit (AST::PathInExpression &path);
-  virtual void visit (AST::TypePathSegment &segment);
-  virtual void visit (AST::TypePathSegmentGeneric &segment);
-  virtual void visit (AST::TypePathSegmentFunction &segment);
-  virtual void visit (AST::TypePath &path);
-  virtual void visit (AST::QualifiedPathInExpression &path);
-  virtual void visit (AST::QualifiedPathInType &path);
+  virtual void visit (AST::PathInExpression &path) = 0;
+  virtual void visit (AST::TypePathSegment &segment) = 0;
+  virtual void visit (AST::TypePathSegmentGeneric &segment) = 0;
+  virtual void visit (AST::TypePathSegmentFunction &segment) = 0;
+  virtual void visit (AST::TypePath &path) = 0;
+  virtual void visit (AST::QualifiedPathInExpression &path) = 0;
+  virtual void visit (AST::QualifiedPathInType &path) = 0;
 
   // rust-expr.h
-  virtual void visit (AST::LiteralExpr &expr);
-  virtual void visit (AST::AttrInputLiteral &attr_input);
-  virtual void visit (AST::MetaItemLitExpr &meta_item);
-  virtual void visit (AST::MetaItemPathLit &meta_item);
-  virtual void visit (AST::BorrowExpr &expr);
-  virtual void visit (AST::DereferenceExpr &expr);
-  virtual void visit (AST::ErrorPropagationExpr &expr);
-  virtual void visit (AST::NegationExpr &expr);
-  virtual void visit (AST::ArithmeticOrLogicalExpr &expr);
-  virtual void visit (AST::ComparisonExpr &expr);
-  virtual void visit (AST::LazyBooleanExpr &expr);
-  virtual void visit (AST::TypeCastExpr &expr);
-  virtual void visit (AST::AssignmentExpr &expr);
-  virtual void visit (AST::CompoundAssignmentExpr &expr);
-  virtual void visit (AST::GroupedExpr &expr);
-  // virtual void visit(ArrayElems& elems);
-  virtual void visit (AST::ArrayElemsValues &elems);
-  virtual void visit (AST::ArrayElemsCopied &elems);
-  virtual void visit (AST::ArrayExpr &expr);
-  virtual void visit (AST::ArrayIndexExpr &expr);
-  virtual void visit (AST::TupleExpr &expr);
-  virtual void visit (AST::TupleIndexExpr &expr);
-  virtual void visit (AST::StructExprStruct &expr);
-  // virtual void visit(StructExprField& field);
-  virtual void visit (AST::StructExprFieldIdentifier &field);
-  virtual void visit (AST::StructExprFieldIdentifierValue &field);
-  virtual void visit (AST::StructExprFieldIndexValue &field);
-  virtual void visit (AST::StructExprStructFields &expr);
-  virtual void visit (AST::StructExprStructBase &expr);
-  virtual void visit (AST::StructExprTuple &expr);
-  virtual void visit (AST::StructExprUnit &expr);
-  // virtual void visit(EnumExprField& field);
-  virtual void visit (AST::EnumExprFieldIdentifier &field);
-  virtual void visit (AST::EnumExprFieldIdentifierValue &field);
-  virtual void visit (AST::EnumExprFieldIndexValue &field);
-  virtual void visit (AST::EnumExprStruct &expr);
-  virtual void visit (AST::EnumExprTuple &expr);
-  virtual void visit (AST::EnumExprFieldless &expr);
-  virtual void visit (AST::CallExpr &expr);
-  virtual void visit (AST::MethodCallExpr &expr);
-  virtual void visit (AST::FieldAccessExpr &expr);
-  virtual void visit (AST::ClosureExprInner &expr);
-  virtual void visit (AST::BlockExpr &expr);
-  virtual void visit (AST::ClosureExprInnerTyped &expr);
-  virtual void visit (AST::ContinueExpr &expr);
-  virtual void visit (AST::BreakExpr &expr);
-  virtual void visit (AST::RangeFromToExpr &expr);
-  virtual void visit (AST::RangeFromExpr &expr);
-  virtual void visit (AST::RangeToExpr &expr);
-  virtual void visit (AST::RangeFullExpr &expr);
-  virtual void visit (AST::RangeFromToInclExpr &expr);
-  virtual void visit (AST::RangeToInclExpr &expr);
-  virtual void visit (AST::ReturnExpr &expr);
-  virtual void visit (AST::UnsafeBlockExpr &expr);
-  virtual void visit (AST::LoopExpr &expr);
-  virtual void visit (AST::WhileLoopExpr &expr);
-  virtual void visit (AST::WhileLetLoopExpr &expr);
-  virtual void visit (AST::ForLoopExpr &expr);
-  virtual void visit (AST::IfExpr &expr);
-  virtual void visit (AST::IfExprConseqElse &expr);
-  virtual void visit (AST::IfExprConseqIf &expr);
-  virtual void visit (AST::IfExprConseqIfLet &expr);
-  virtual void visit (AST::IfLetExpr &expr);
-  virtual void visit (AST::IfLetExprConseqElse &expr);
-  virtual void visit (AST::IfLetExprConseqIf &expr);
-  virtual void visit (AST::IfLetExprConseqIfLet &expr);
-  // virtual void visit(MatchCase& match_case);
-  virtual void visit (AST::MatchCaseBlockExpr &match_case);
-  virtual void visit (AST::MatchCaseExpr &match_case);
-  virtual void visit (AST::MatchExpr &expr);
-  virtual void visit (AST::AwaitExpr &expr);
-  virtual void visit (AST::AsyncBlockExpr &expr);
+  virtual void visit (AST::LiteralExpr &expr) = 0;
+  virtual void visit (AST::AttrInputLiteral &attr_input) = 0;
+  virtual void visit (AST::MetaItemLitExpr &meta_item) = 0;
+  virtual void visit (AST::MetaItemPathLit &meta_item) = 0;
+  virtual void visit (AST::BorrowExpr &expr) = 0;
+  virtual void visit (AST::DereferenceExpr &expr) = 0;
+  virtual void visit (AST::ErrorPropagationExpr &expr) = 0;
+  virtual void visit (AST::NegationExpr &expr) = 0;
+  virtual void visit (AST::ArithmeticOrLogicalExpr &expr) = 0;
+  virtual void visit (AST::ComparisonExpr &expr) = 0;
+  virtual void visit (AST::LazyBooleanExpr &expr) = 0;
+  virtual void visit (AST::TypeCastExpr &expr) = 0;
+  virtual void visit (AST::AssignmentExpr &expr) = 0;
+  virtual void visit (AST::CompoundAssignmentExpr &expr) = 0;
+  virtual void visit (AST::GroupedExpr &expr) = 0;
+  // virtual void visit(ArrayElems& elems) = 0;
+  virtual void visit (AST::ArrayElemsValues &elems) = 0;
+  virtual void visit (AST::ArrayElemsCopied &elems) = 0;
+  virtual void visit (AST::ArrayExpr &expr) = 0;
+  virtual void visit (AST::ArrayIndexExpr &expr) = 0;
+  virtual void visit (AST::TupleExpr &expr) = 0;
+  virtual void visit (AST::TupleIndexExpr &expr) = 0;
+  virtual void visit (AST::StructExprStruct &expr) = 0;
+  // virtual void visit(StructExprField& field) = 0;
+  virtual void visit (AST::StructExprFieldIdentifier &field) = 0;
+  virtual void visit (AST::StructExprFieldIdentifierValue &field) = 0;
+  virtual void visit (AST::StructExprFieldIndexValue &field) = 0;
+  virtual void visit (AST::StructExprStructFields &expr) = 0;
+  virtual void visit (AST::StructExprStructBase &expr) = 0;
+  virtual void visit (AST::StructExprTuple &expr) = 0;
+  virtual void visit (AST::StructExprUnit &expr) = 0;
+  // virtual void visit(EnumExprField& field) = 0;
+  virtual void visit (AST::EnumExprFieldIdentifier &field) = 0;
+  virtual void visit (AST::EnumExprFieldIdentifierValue &field) = 0;
+  virtual void visit (AST::EnumExprFieldIndexValue &field) = 0;
+  virtual void visit (AST::EnumExprStruct &expr) = 0;
+  virtual void visit (AST::EnumExprTuple &expr) = 0;
+  virtual void visit (AST::EnumExprFieldless &expr) = 0;
+  virtual void visit (AST::CallExpr &expr) = 0;
+  virtual void visit (AST::MethodCallExpr &expr) = 0;
+  virtual void visit (AST::FieldAccessExpr &expr) = 0;
+  virtual void visit (AST::ClosureExprInner &expr) = 0;
+  virtual void visit (AST::BlockExpr &expr) = 0;
+  virtual void visit (AST::ClosureExprInnerTyped &expr) = 0;
+  virtual void visit (AST::ContinueExpr &expr) = 0;
+  virtual void visit (AST::BreakExpr &expr) = 0;
+  virtual void visit (AST::RangeFromToExpr &expr) = 0;
+  virtual void visit (AST::RangeFromExpr &expr) = 0;
+  virtual void visit (AST::RangeToExpr &expr) = 0;
+  virtual void visit (AST::RangeFullExpr &expr) = 0;
+  virtual void visit (AST::RangeFromToInclExpr &expr) = 0;
+  virtual void visit (AST::RangeToInclExpr &expr) = 0;
+  virtual void visit (AST::ReturnExpr &expr) = 0;
+  virtual void visit (AST::UnsafeBlockExpr &expr) = 0;
+  virtual void visit (AST::LoopExpr &expr) = 0;
+  virtual void visit (AST::WhileLoopExpr &expr) = 0;
+  virtual void visit (AST::WhileLetLoopExpr &expr) = 0;
+  virtual void visit (AST::ForLoopExpr &expr) = 0;
+  virtual void visit (AST::IfExpr &expr) = 0;
+  virtual void visit (AST::IfExprConseqElse &expr) = 0;
+  virtual void visit (AST::IfExprConseqIf &expr) = 0;
+  virtual void visit (AST::IfExprConseqIfLet &expr) = 0;
+  virtual void visit (AST::IfLetExpr &expr) = 0;
+  virtual void visit (AST::IfLetExprConseqElse &expr) = 0;
+  virtual void visit (AST::IfLetExprConseqIf &expr) = 0;
+  virtual void visit (AST::IfLetExprConseqIfLet &expr) = 0;
+  // virtual void visit(MatchCase& match_case) = 0;
+  virtual void visit (AST::MatchCaseBlockExpr &match_case) = 0;
+  virtual void visit (AST::MatchCaseExpr &match_case) = 0;
+  virtual void visit (AST::MatchExpr &expr) = 0;
+  virtual void visit (AST::AwaitExpr &expr) = 0;
+  virtual void visit (AST::AsyncBlockExpr &expr) = 0;
 
   // rust-item.h
-  virtual void visit (AST::TypeParam &param);
-  // virtual void visit(WhereClauseItem& item);
-  virtual void visit (AST::LifetimeWhereClauseItem &item);
-  virtual void visit (AST::TypeBoundWhereClauseItem &item);
-  virtual void visit (AST::Method &method);
-  virtual void visit (AST::ModuleBodied &module);
-  virtual void visit (AST::ModuleNoBody &module);
-  virtual void visit (AST::ExternCrate &crate);
-  // virtual void visit(UseTree& use_tree);
-  virtual void visit (AST::UseTreeGlob &use_tree);
-  virtual void visit (AST::UseTreeList &use_tree);
-  virtual void visit (AST::UseTreeRebind &use_tree);
-  virtual void visit (AST::UseDeclaration &use_decl);
-  virtual void visit (AST::Function &function);
-  virtual void visit (AST::TypeAlias &type_alias);
-  virtual void visit (AST::StructStruct &struct_item);
-  virtual void visit (AST::TupleStruct &tuple_struct);
-  virtual void visit (AST::EnumItem &item);
-  virtual void visit (AST::EnumItemTuple &item);
-  virtual void visit (AST::EnumItemStruct &item);
-  virtual void visit (AST::EnumItemDiscriminant &item);
-  virtual void visit (AST::Enum &enum_item);
-  virtual void visit (AST::Union &union_item);
-  virtual void visit (AST::ConstantItem &const_item);
-  virtual void visit (AST::StaticItem &static_item);
-  virtual void visit (AST::TraitItemFunc &item);
-  virtual void visit (AST::TraitItemMethod &item);
-  virtual void visit (AST::TraitItemConst &item);
-  virtual void visit (AST::TraitItemType &item);
-  virtual void visit (AST::Trait &trait);
-  virtual void visit (AST::InherentImpl &impl);
-  virtual void visit (AST::TraitImpl &impl);
-  // virtual void visit(ExternalItem& item);
-  virtual void visit (AST::ExternalStaticItem &item);
-  virtual void visit (AST::ExternalFunctionItem &item);
-  virtual void visit (AST::ExternBlock &block);
+  virtual void visit (AST::TypeParam &param) = 0;
+  // virtual void visit(WhereClauseItem& item) = 0;
+  virtual void visit (AST::LifetimeWhereClauseItem &item) = 0;
+  virtual void visit (AST::TypeBoundWhereClauseItem &item) = 0;
+  virtual void visit (AST::Method &method) = 0;
+  virtual void visit (AST::ModuleBodied &module) = 0;
+  virtual void visit (AST::ModuleNoBody &module) = 0;
+  virtual void visit (AST::ExternCrate &crate) = 0;
+  // virtual void visit(UseTree& use_tree) = 0;
+  virtual void visit (AST::UseTreeGlob &use_tree) = 0;
+  virtual void visit (AST::UseTreeList &use_tree) = 0;
+  virtual void visit (AST::UseTreeRebind &use_tree) = 0;
+  virtual void visit (AST::UseDeclaration &use_decl) = 0;
+  virtual void visit (AST::Function &function) = 0;
+  virtual void visit (AST::TypeAlias &type_alias) = 0;
+  virtual void visit (AST::StructStruct &struct_item) = 0;
+  virtual void visit (AST::TupleStruct &tuple_struct) = 0;
+  virtual void visit (AST::EnumItem &item) = 0;
+  virtual void visit (AST::EnumItemTuple &item) = 0;
+  virtual void visit (AST::EnumItemStruct &item) = 0;
+  virtual void visit (AST::EnumItemDiscriminant &item) = 0;
+  virtual void visit (AST::Enum &enum_item) = 0;
+  virtual void visit (AST::Union &union_item) = 0;
+  virtual void visit (AST::ConstantItem &const_item) = 0;
+  virtual void visit (AST::StaticItem &static_item) = 0;
+  virtual void visit (AST::TraitItemFunc &item) = 0;
+  virtual void visit (AST::TraitItemMethod &item) = 0;
+  virtual void visit (AST::TraitItemConst &item) = 0;
+  virtual void visit (AST::TraitItemType &item) = 0;
+  virtual void visit (AST::Trait &trait) = 0;
+  virtual void visit (AST::InherentImpl &impl) = 0;
+  virtual void visit (AST::TraitImpl &impl) = 0;
+  // virtual void visit(ExternalItem& item) = 0;
+  virtual void visit (AST::ExternalStaticItem &item) = 0;
+  virtual void visit (AST::ExternalFunctionItem &item) = 0;
+  virtual void visit (AST::ExternBlock &block) = 0;
 
   // rust-macro.h
-  virtual void visit (AST::MacroMatchFragment &match);
-  virtual void visit (AST::MacroMatchRepetition &match);
-  virtual void visit (AST::MacroMatcher &matcher);
-  virtual void visit (AST::MacroRulesDefinition &rules_def);
-  virtual void visit (AST::MacroInvocation &macro_invoc);
-  virtual void visit (AST::MetaItemPath &meta_item);
-  virtual void visit (AST::MetaItemSeq &meta_item);
-  virtual void visit (AST::MetaWord &meta_item);
-  virtual void visit (AST::MetaNameValueStr &meta_item);
-  virtual void visit (AST::MetaListPaths &meta_item);
-  virtual void visit (AST::MetaListNameValueStr &meta_item);
+  virtual void visit (AST::MacroMatchFragment &match) = 0;
+  virtual void visit (AST::MacroMatchRepetition &match) = 0;
+  virtual void visit (AST::MacroMatcher &matcher) = 0;
+  virtual void visit (AST::MacroRulesDefinition &rules_def) = 0;
+  virtual void visit (AST::MacroInvocation &macro_invoc) = 0;
+  virtual void visit (AST::MetaItemPath &meta_item) = 0;
+  virtual void visit (AST::MetaItemSeq &meta_item) = 0;
+  virtual void visit (AST::MetaWord &meta_item) = 0;
+  virtual void visit (AST::MetaNameValueStr &meta_item) = 0;
+  virtual void visit (AST::MetaListPaths &meta_item) = 0;
+  virtual void visit (AST::MetaListNameValueStr &meta_item) = 0;
 
   // rust-pattern.h
-  virtual void visit (AST::LiteralPattern &pattern);
-  virtual void visit (AST::IdentifierPattern &pattern);
-  virtual void visit (AST::WildcardPattern &pattern);
-  // virtual void visit(RangePatternBound& bound);
-  virtual void visit (AST::RangePatternBoundLiteral &bound);
-  virtual void visit (AST::RangePatternBoundPath &bound);
-  virtual void visit (AST::RangePatternBoundQualPath &bound);
-  virtual void visit (AST::RangePattern &pattern);
-  virtual void visit (AST::ReferencePattern &pattern);
-  // virtual void visit(StructPatternField& field);
-  virtual void visit (AST::StructPatternFieldTuplePat &field);
-  virtual void visit (AST::StructPatternFieldIdentPat &field);
-  virtual void visit (AST::StructPatternFieldIdent &field);
-  virtual void visit (AST::StructPattern &pattern);
-  // virtual void visit(TupleStructItems& tuple_items);
-  virtual void visit (AST::TupleStructItemsNoRange &tuple_items);
-  virtual void visit (AST::TupleStructItemsRange &tuple_items);
-  virtual void visit (AST::TupleStructPattern &pattern);
-  // virtual void visit(TuplePatternItems& tuple_items);
-  virtual void visit (AST::TuplePatternItemsMultiple &tuple_items);
-  virtual void visit (AST::TuplePatternItemsRanged &tuple_items);
-  virtual void visit (AST::TuplePattern &pattern);
-  virtual void visit (AST::GroupedPattern &pattern);
-  virtual void visit (AST::SlicePattern &pattern);
+  virtual void visit (AST::LiteralPattern &pattern) = 0;
+  virtual void visit (AST::IdentifierPattern &pattern) = 0;
+  virtual void visit (AST::WildcardPattern &pattern) = 0;
+  // virtual void visit(RangePatternBound& bound) = 0;
+  virtual void visit (AST::RangePatternBoundLiteral &bound) = 0;
+  virtual void visit (AST::RangePatternBoundPath &bound) = 0;
+  virtual void visit (AST::RangePatternBoundQualPath &bound) = 0;
+  virtual void visit (AST::RangePattern &pattern) = 0;
+  virtual void visit (AST::ReferencePattern &pattern) = 0;
+  // virtual void visit(StructPatternField& field) = 0;
+  virtual void visit (AST::StructPatternFieldTuplePat &field) = 0;
+  virtual void visit (AST::StructPatternFieldIdentPat &field) = 0;
+  virtual void visit (AST::StructPatternFieldIdent &field) = 0;
+  virtual void visit (AST::StructPattern &pattern) = 0;
+  // virtual void visit(TupleStructItems& tuple_items) = 0;
+  virtual void visit (AST::TupleStructItemsNoRange &tuple_items) = 0;
+  virtual void visit (AST::TupleStructItemsRange &tuple_items) = 0;
+  virtual void visit (AST::TupleStructPattern &pattern) = 0;
+  // virtual void visit(TuplePatternItems& tuple_items) = 0;
+  virtual void visit (AST::TuplePatternItemsMultiple &tuple_items) = 0;
+  virtual void visit (AST::TuplePatternItemsRanged &tuple_items) = 0;
+  virtual void visit (AST::TuplePattern &pattern) = 0;
+  virtual void visit (AST::GroupedPattern &pattern) = 0;
+  virtual void visit (AST::SlicePattern &pattern) = 0;
 
   // rust-stmt.h
-  virtual void visit (AST::EmptyStmt &stmt);
-  virtual void visit (AST::LetStmt &stmt);
-  virtual void visit (AST::ExprStmtWithoutBlock &stmt);
-  virtual void visit (AST::ExprStmtWithBlock &stmt);
+  virtual void visit (AST::EmptyStmt &stmt) = 0;
+  virtual void visit (AST::LetStmt &stmt) = 0;
+  virtual void visit (AST::ExprStmtWithoutBlock &stmt) = 0;
+  virtual void visit (AST::ExprStmtWithBlock &stmt) = 0;
 
   // rust-type.h
-  virtual void visit (AST::TraitBound &bound);
-  virtual void visit (AST::ImplTraitType &type);
-  virtual void visit (AST::TraitObjectType &type);
-  virtual void visit (AST::ParenthesisedType &type);
-  virtual void visit (AST::ImplTraitTypeOneBound &type);
-  virtual void visit (AST::TraitObjectTypeOneBound &type);
-  virtual void visit (AST::TupleType &type);
-  virtual void visit (AST::NeverType &type);
-  virtual void visit (AST::RawPointerType &type);
-  virtual void visit (AST::ReferenceType &type);
-  virtual void visit (AST::ArrayType &type);
-  virtual void visit (AST::SliceType &type);
-  virtual void visit (AST::InferredType &type);
-  virtual void visit (AST::BareFunctionType &type);
+  virtual void visit (AST::TraitBound &bound) = 0;
+  virtual void visit (AST::ImplTraitType &type) = 0;
+  virtual void visit (AST::TraitObjectType &type) = 0;
+  virtual void visit (AST::ParenthesisedType &type) = 0;
+  virtual void visit (AST::ImplTraitTypeOneBound &type) = 0;
+  virtual void visit (AST::TraitObjectTypeOneBound &type) = 0;
+  virtual void visit (AST::TupleType &type) = 0;
+  virtual void visit (AST::NeverType &type) = 0;
+  virtual void visit (AST::RawPointerType &type) = 0;
+  virtual void visit (AST::ReferenceType &type) = 0;
+  virtual void visit (AST::ArrayType &type) = 0;
+  virtual void visit (AST::SliceType &type) = 0;
+  virtual void visit (AST::InferredType &type) = 0;
+  virtual void visit (AST::BareFunctionType &type) = 0;
 
 private:
-  TypeResolution (AST::Crate &crate, TopLevelScan &toplevel);
-
-  bool go ();
-
-  bool typesAreCompatible (AST::Type *lhs, AST::Type *rhs, Location locus);
+  virtual bool go () = 0;
+
+protected:
+  Resolution (AST::Crate &crate, TopLevelScan &toplevel)
+    : crate (crate), toplevel (toplevel)
+  {
+    typeScope.Push ();
+    scope.Push ();
+  };
 
   Scope<AST::Type *> scope;
   Scope<AST::Type *> typeScope;