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| Rev | Author | Line No. | Line | 
|---|---|---|---|
| 14 | pmbaty | 1 | //===--- MSVCErrorWorkarounds.h - Enable future<Error> in MSVC --*- 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 | // MSVC's promise/future implementation requires types to be default | ||
| 10 | // constructible, so this header provides analogues of Error an Expected | ||
| 11 | // that are default constructed in a safely destructible state. | ||
| 12 | // | ||
| 13 | // FIXME: Kill off this header and migrate all users to Error/Expected once we | ||
| 14 | //        move to MSVC versions that support non-default-constructible types. | ||
| 15 | // | ||
| 16 | //===----------------------------------------------------------------------===// | ||
| 17 | |||
| 18 | #ifndef LLVM_SUPPORT_MSVCERRORWORKAROUNDS_H | ||
| 19 | #define LLVM_SUPPORT_MSVCERRORWORKAROUNDS_H | ||
| 20 | |||
| 21 | #include "llvm/Support/Error.h" | ||
| 22 | |||
| 23 | namespace llvm { | ||
| 24 | |||
| 25 | // A default-constructible llvm::Error that is suitable for use with MSVC's | ||
| 26 | // std::future implementation which requires default constructible types. | ||
| 27 | class MSVCPError : public Error { | ||
| 28 | public: | ||
| 29 | MSVCPError() { (void)!!*this; } | ||
| 30 | |||
| 31 | MSVCPError(MSVCPError &&Other) : Error(std::move(Other)) {} | ||
| 32 | |||
| 33 | MSVCPError &operator=(MSVCPError Other) { | ||
| 34 | Error::operator=(std::move(Other)); | ||
| 35 | return *this; | ||
| 36 |   } | ||
| 37 | |||
| 38 | MSVCPError(Error Err) : Error(std::move(Err)) {} | ||
| 39 | }; | ||
| 40 | |||
| 41 | // A default-constructible llvm::Expected that is suitable for use with MSVC's | ||
| 42 | // std::future implementation, which requires default constructible types. | ||
| 43 | template <typename T> class MSVCPExpected : public Expected<T> { | ||
| 44 | public: | ||
| 45 | MSVCPExpected() | ||
| 46 | : Expected<T>(make_error<StringError>("", inconvertibleErrorCode())) { | ||
| 47 | consumeError(this->takeError()); | ||
| 48 |   } | ||
| 49 | |||
| 50 | MSVCPExpected(MSVCPExpected &&Other) : Expected<T>(std::move(Other)) {} | ||
| 51 | |||
| 52 | MSVCPExpected &operator=(MSVCPExpected &&Other) { | ||
| 53 | Expected<T>::operator=(std::move(Other)); | ||
| 54 | return *this; | ||
| 55 |   } | ||
| 56 | |||
| 57 | MSVCPExpected(Error Err) : Expected<T>(std::move(Err)) {} | ||
| 58 | |||
| 59 | template <typename OtherT> | ||
| 60 |   MSVCPExpected( | ||
| 61 |       OtherT &&Val, | ||
| 62 | std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr) | ||
| 63 | : Expected<T>(std::move(Val)) {} | ||
| 64 | |||
| 65 | template <class OtherT> | ||
| 66 |   MSVCPExpected( | ||
| 67 | Expected<OtherT> &&Other, | ||
| 68 | std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr) | ||
| 69 | : Expected<T>(std::move(Other)) {} | ||
| 70 | |||
| 71 | template <class OtherT> | ||
| 72 | explicit MSVCPExpected( | ||
| 73 | Expected<OtherT> &&Other, | ||
| 74 | std::enable_if_t<!std::is_convertible<OtherT, T>::value> * = nullptr) | ||
| 75 | : Expected<T>(std::move(Other)) {} | ||
| 76 | }; | ||
| 77 | |||
| 78 | } // end namespace llvm | ||
| 79 | |||
| 80 | #endif // LLVM_SUPPORT_MSVCERRORWORKAROUNDS_H |