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//===- TemplateArgumentVisitor.h - Visitor for TArg subclasses --*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines the TemplateArgumentVisitor interface.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CLANG_AST_TEMPLATEARGUMENTVISITOR_H
#define LLVM_CLANG_AST_TEMPLATEARGUMENTVISITOR_H
#include "clang/AST/TemplateBase.h"
namespace clang {
namespace templateargumentvisitor {
/// A simple visitor class that helps create template argument visitors.
template <template <typename> class Ref, typename ImplClass,
typename RetTy = void, typename... ParamTys>
class Base {
public:
#define REF(CLASS) typename Ref<CLASS>::type
#define DISPATCH(NAME) \
case TemplateArgument::NAME: \
return static_cast<ImplClass *>(this)->Visit##NAME##TemplateArgument( \
TA, std::forward<ParamTys>(P)...)
RetTy Visit(REF(TemplateArgument) TA, ParamTys... P) {
switch (TA.getKind()) {
DISPATCH(Null);
DISPATCH(Type);
DISPATCH(Declaration);
DISPATCH(NullPtr);
DISPATCH(Integral);
DISPATCH(Template);
DISPATCH(TemplateExpansion);
DISPATCH(Expression);
DISPATCH(Pack);
}
llvm_unreachable("TemplateArgument is not covered in switch!");
}
// If the implementation chooses not to implement a certain visit
// method, fall back to the parent.
#define VISIT_METHOD(CATEGORY) \
RetTy Visit##CATEGORY##TemplateArgument(REF(TemplateArgument) TA, \
ParamTys... P) { \
return VisitTemplateArgument(TA, std::forward<ParamTys>(P)...); \
}
VISIT_METHOD(Null);
VISIT_METHOD(Type);
VISIT_METHOD(Declaration);
VISIT_METHOD(NullPtr);
VISIT_METHOD(Integral);
VISIT_METHOD(Template);
VISIT_METHOD(TemplateExpansion);
VISIT_METHOD(Expression);
VISIT_METHOD(Pack);
RetTy VisitTemplateArgument(REF(TemplateArgument), ParamTys...) {
return RetTy();
}
#undef REF
#undef DISPATCH
#undef VISIT_METHOD
};
} // namespace templateargumentvisitor
/// A simple visitor class that helps create template argument visitors.
///
/// This class does not preserve constness of TemplateArgument references (see
/// also ConstTemplateArgumentVisitor).
template <typename ImplClass, typename RetTy = void, typename... ParamTys>
class TemplateArgumentVisitor
: public templateargumentvisitor::Base<std::add_lvalue_reference, ImplClass,
RetTy, ParamTys...> {};
/// A simple visitor class that helps create template argument visitors.
///
/// This class preserves constness of TemplateArgument references (see also
/// TemplateArgumentVisitor).
template <typename ImplClass, typename RetTy = void, typename... ParamTys>
class ConstTemplateArgumentVisitor
: public templateargumentvisitor::Base<llvm::make_const_ref, ImplClass,
RetTy, ParamTys...> {};
} // namespace clang
#endif // LLVM_CLANG_AST_TEMPLATEARGUMENTVISITOR_H