const char* attr_name,
      absl::Span<const AbstractOperation*> values) override;

  Status SetOpName(const char* op_name) override;

  MLIRContext* GetContext() { return context_; }

  Status AddRef(Type type, Type* output_type);

  Status Create(ArrayRef<Value> operands, OperationState**);

  // For LLVM style RTTI.
  static bool classof(const AbstractOperation* ptr) {
    return ptr->getKind() == kMlir;

// AddRef<T>::type is T if T is a reference; otherwise it's T&.  This
// is the same as tr1::add_reference<T>::type.
template <typename T>
struct AddRef { typedef T& type; };  // NOLINT
template <typename T>
struct AddRef<T&> { typedef T& type; };  // NOLINT

// A handy wrapper for AddRef.
#define GTEST_ADD_REF_(T) typename ::std::tr1::gtest_internal::AddRef<T>::type