//===--- RefactoringOptionVisitor.h - Clang refactoring library -----------===//

//

// 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

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_TOOLING_REFACTORING_REFACTORINGOPTIONVISITOR_H

#define LLVM_CLANG_TOOLING_REFACTORING_REFACTORINGOPTIONVISITOR_H

#include "clang/Basic/LLVM.h"

#include <type_traits>

namespace clang {

namespace tooling {

class RefactoringOption;

/// An interface that declares functions that handle different refactoring

/// option types.

///

/// A valid refactoring option type must have a corresponding \c visit

/// declaration in this interface.

class RefactoringOptionVisitor {

public:

  virtual ~RefactoringOptionVisitor() {}

  virtual void visit(const RefactoringOption &Opt,

                     Optional<std::string> &Value) = 0;

};

namespace traits {

namespace internal {

template <typename T> struct HasHandle {

private:

  template <typename ClassT>

  static auto check(ClassT *) -> typename std::is_same<

      decltype(std::declval<RefactoringOptionVisitor>().visit(

          std::declval<RefactoringOption>(), *std::declval<Optional<T> *>())),

      void>::type;

  template <typename> static std::false_type check(...);

public:

  using Type = decltype(check<RefactoringOptionVisitor>(nullptr));

};

} // end namespace internal

/// A type trait that returns true iff the given type is a type that can be

/// stored in a refactoring option.

template <typename T>

struct IsValidOptionType : internal::HasHandle<T>::Type {};

} // end namespace traits

} // end namespace tooling

} // end namespace clang

#endif // LLVM_CLANG_TOOLING_REFACTORING_REFACTORINGOPTIONVISITOR_H