1//===-- None.h - Simple null value for implicit construction ------*- C++ -*-=// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides None, an enumerator for use in implicit constructors 11// of various (usually templated) types to make such construction more 12// terse. 13// 14//===----------------------------------------------------------------------===// 15 16#ifndef LLVM_ADT_NONE_H 17#define LLVM_ADT_NONE_H 18 19namespace llvm { 20/// \brief A simple null object to allow implicit construction of Optional<T> 21/// and similar types without having to spell out the specialization's name. 22enum class NoneType { None }; 23const NoneType None = None; 24} 25 26#endif 27