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 19 namespace 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. 22 // (constant value 1 in an attempt to workaround MSVC build issue... ) 23 enum class NoneType { None = 1 }; 24 const NoneType None = NoneType::None; 25 } 26 27 #endif 28
