1 files changed, 62 insertions, 0 deletions
diff --git a/include/clang/Tooling/Refactoring/RefactoringOptionVisitor.h b/include/clang/Tooling/Refactoring/RefactoringOptionVisitor.h
new file mode 100644
index 0000000000000..aea8fa549392b
--- /dev/null
+++ b/include/clang/Tooling/Refactoring/RefactoringOptionVisitor.h
@@ -0,0 +1,62 @@
+//===--- RefactoringOptionVisitor.h - Clang refactoring library -----------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLING_REFACTOR_REFACTORING_OPTION_VISITOR_H
+#define LLVM_CLANG_TOOLING_REFACTOR_REFACTORING_OPTION_VISITOR_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_REFACTOR_REFACTORING_OPTION_VISITOR_H