clang  8.0.0
TemplateArgumentVisitor.h
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1 //===- TemplateArgumentVisitor.h - Visitor for TArg subclasses --*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines the TemplateArgumentVisitor interface.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_CLANG_AST_TEMPLATEARGUMENTVISITOR_H
15 #define LLVM_CLANG_AST_TEMPLATEARGUMENTVISITOR_H
16 
17 #include "clang/AST/TemplateBase.h"
18 
19 namespace clang {
20 
21 namespace templateargumentvisitor {
22 
23 /// A simple visitor class that helps create template argument visitors.
24 template <template <typename> class Ref, typename ImplClass,
25  typename RetTy = void, typename... ParamTys>
26 class Base {
27 public:
28 #define REF(CLASS) typename Ref<CLASS>::type
29 #define DISPATCH(NAME) \
30  case TemplateArgument::NAME: \
31  return static_cast<ImplClass *>(this)->Visit##NAME##TemplateArgument( \
32  TA, std::forward<ParamTys>(P)...)
33 
34  RetTy Visit(REF(TemplateArgument) TA, ParamTys... P) {
35  switch (TA.getKind()) {
36  DISPATCH(Null);
37  DISPATCH(Type);
38  DISPATCH(Declaration);
39  DISPATCH(NullPtr);
40  DISPATCH(Integral);
41  DISPATCH(Template);
42  DISPATCH(TemplateExpansion);
43  DISPATCH(Expression);
44  DISPATCH(Pack);
45  }
46  llvm_unreachable("TemplateArgument is not covered in switch!");
47  }
48 
49  // If the implementation chooses not to implement a certain visit
50  // method, fall back to the parent.
51 
52 #define VISIT_METHOD(CATEGORY) \
53  RetTy Visit##CATEGORY##TemplateArgument(REF(TemplateArgument) TA, \
54  ParamTys... P) { \
55  return VisitTemplateArgument(TA, std::forward<ParamTys>(P)...); \
56  }
57 
58  VISIT_METHOD(Null);
59  VISIT_METHOD(Type);
60  VISIT_METHOD(Declaration);
61  VISIT_METHOD(NullPtr);
62  VISIT_METHOD(Integral);
63  VISIT_METHOD(Template);
64  VISIT_METHOD(TemplateExpansion);
65  VISIT_METHOD(Expression);
66  VISIT_METHOD(Pack);
67 
69  return RetTy();
70  }
71 
72 #undef REF
73 #undef DISPATCH
74 #undef VISIT_METHOD
75 };
76 
77 } // namespace templateargumentvisitor
78 
79 /// A simple visitor class that helps create template argument visitors.
80 ///
81 /// This class does not preserve constness of TemplateArgument references (see
82 /// also ConstTemplateArgumentVisitor).
83 template <typename ImplClass, typename RetTy = void, typename... ParamTys>
85  : public templateargumentvisitor::Base<std::add_lvalue_reference, ImplClass,
86  RetTy, ParamTys...> {};
87 
88 /// A simple visitor class that helps create template argument visitors.
89 ///
90 /// This class preserves constness of TemplateArgument references (see also
91 /// TemplateArgumentVisitor).
92 template <typename ImplClass, typename RetTy = void, typename... ParamTys>
94  : public templateargumentvisitor::Base<llvm::make_const_ref, ImplClass,
95  RetTy, ParamTys...> {};
96 
97 } // namespace clang
98 
99 #endif // LLVM_CLANG_AST_TEMPLATEARGUMENTVISITOR_H
RetTy VisitTemplateArgument(REF(TemplateArgument), ParamTys...)
RetTy Visit(REF(TemplateArgument) TA, ParamTys... P)
StringRef P
The base class of the type hierarchy.
Definition: Type.h:1407
#define REF(CLASS)
A simple visitor class that helps create template argument visitors.
A simple visitor class that helps create template argument visitors.
A simple visitor class that helps create template argument visitors.
Represents a template argument.
Definition: TemplateBase.h:51
Dataflow Directional Tag Classes.
ArgKind getKind() const
Return the kind of stored template argument.
Definition: TemplateBase.h:235
#define DISPATCH(NAME)