llvm/clang/include/clang/AST/TemplateArgumentVisitor.h

//===- 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 { … };

} // 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