1 //===-- None.h - Simple null value for implicit construction ------*- C++ -*-=// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 /// 9 /// \file 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 #include "llvm/Support/Compiler.h" 20 #include <optional> 21 22 namespace llvm { 23 /// A simple null object to allow implicit construction of std::optional<T> 24 /// and similar types without having to spell out the specialization's name. 25 LLVM_DEPRECATED("Use std::nullopt_t instead", "std::nullopt_t") 26 typedef std::nullopt_t NoneType; 27 LLVM_DEPRECATED("Use std::nullopt instead.", "std::nullopt") 28 inline constexpr std::nullopt_t None = std::nullopt; 29 } 30 31 #endif 32