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 NoneType {
23  None
24};
25}
26
27#endif
28