LLVM 19.0.0git
MSVCErrorWorkarounds.h
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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
23namespace 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.
27class MSVCPError : public Error {
28public:
29 MSVCPError() { (void)!!*this; }
30
32
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.
43template <typename T> class MSVCPExpected : public Expected<T> {
44public:
47 consumeError(this->takeError());
48 }
49
51
53 Expected<T>::operator=(std::move(Other));
54 return *this;
55 }
56
58
59 template <typename OtherT>
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>
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(
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
Lightweight error class with error context and mandatory checking.
Definition: Error.h:160
Error & operator=(const Error &Other)=delete
Tagged union holding either a T or a Error.
Definition: Error.h:474
Error takeError()
Take ownership of the stored error.
Definition: Error.h:601
Expected & operator=(Expected &&Other)
Move-assign from another Expected<T>.
Definition: Error.h:548
MSVCPError(MSVCPError &&Other)
MSVCPError & operator=(MSVCPError Other)
MSVCPExpected(Expected< OtherT > &&Other, std::enable_if_t<!std::is_convertible< OtherT, T >::value > *=nullptr)
MSVCPExpected(Expected< OtherT > &&Other, std::enable_if_t< std::is_convertible< OtherT, T >::value > *=nullptr)
MSVCPExpected(MSVCPExpected &&Other)
MSVCPExpected(OtherT &&Val, std::enable_if_t< std::is_convertible< OtherT, T >::value > *=nullptr)
MSVCPExpected & operator=(MSVCPExpected &&Other)
This class wraps a string in an Error.
Definition: Error.h:1221
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
std::error_code inconvertibleErrorCode()
The value returned by this function can be returned from convertToErrorCode for Error values where no...
Definition: Error.cpp:90
Error make_error(ArgTs &&... Args)
Make a Error instance representing failure using the given error info type.
Definition: Error.h:338
@ Other
Any other memory.
OutputIt move(R &&Range, OutputIt Out)
Provide wrappers to std::move which take ranges instead of having to pass begin/end explicitly.
Definition: STLExtras.h:1858
void consumeError(Error Err)
Consume a Error without doing anything.
Definition: Error.h:1041
Implement std::hash so that hash_code can be used in STL containers.
Definition: BitVector.h:858