xref: /freebsd/contrib/llvm-project/libcxx/include/__expected/bad_expected_access.h (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
1 // -*- C++ -*-
2 //===----------------------------------------------------------------------===//
3 //
4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5 // See https://llvm.org/LICENSE.txt for license information.
6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //
8 //===----------------------------------------------------------------------===//
9 #ifndef _LIBCPP___EXPECTED_BAD_EXPECTED_ACCESS_H
10 #define _LIBCPP___EXPECTED_BAD_EXPECTED_ACCESS_H
11 
12 #include <__config>
13 #include <__exception/exception.h>
14 #include <__utility/move.h>
15 
16 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
17 #  pragma GCC system_header
18 #endif
19 
20 _LIBCPP_PUSH_MACROS
21 #include <__undef_macros>
22 
23 #if _LIBCPP_STD_VER >= 23
24 
25 _LIBCPP_BEGIN_NAMESPACE_STD
26 
27 template <class _Err>
28 class bad_expected_access;
29 
30 template <>
31 class bad_expected_access<void> : public exception {
32 protected:
33   _LIBCPP_HIDE_FROM_ABI bad_expected_access() noexcept                             = default;
34   _LIBCPP_HIDE_FROM_ABI bad_expected_access(const bad_expected_access&)            = default;
35   _LIBCPP_HIDE_FROM_ABI bad_expected_access(bad_expected_access&&)                 = default;
36   _LIBCPP_HIDE_FROM_ABI bad_expected_access& operator=(const bad_expected_access&) = default;
37   _LIBCPP_HIDE_FROM_ABI bad_expected_access& operator=(bad_expected_access&&)      = default;
38   _LIBCPP_HIDE_FROM_ABI_VIRTUAL ~bad_expected_access() override                    = default;
39 
40 public:
41   // The way this has been designed (by using a class template below) means that we'll already
42   // have a profusion of these vtables in TUs, and the dynamic linker will already have a bunch
43   // of work to do. So it is not worth hiding the <void> specialization in the dylib, given that
44   // it adds deployment target restrictions.
45   _LIBCPP_HIDE_FROM_ABI_VIRTUAL const char* what() const noexcept override { return "bad access to std::expected"; }
46 };
47 
48 template <class _Err>
49 class bad_expected_access : public bad_expected_access<void> {
50 public:
51   _LIBCPP_HIDE_FROM_ABI explicit bad_expected_access(_Err __e) : __unex_(std::move(__e)) {}
52 
53   _LIBCPP_HIDE_FROM_ABI _Err& error() & noexcept { return __unex_; }
54   _LIBCPP_HIDE_FROM_ABI const _Err& error() const& noexcept { return __unex_; }
55   _LIBCPP_HIDE_FROM_ABI _Err&& error() && noexcept { return std::move(__unex_); }
56   _LIBCPP_HIDE_FROM_ABI const _Err&& error() const&& noexcept { return std::move(__unex_); }
57 
58 private:
59   _Err __unex_;
60 };
61 
62 _LIBCPP_END_NAMESPACE_STD
63 
64 #endif // _LIBCPP_STD_VER >= 23
65 
66 _LIBCPP_POP_MACROS
67 
68 #endif // _LIBCPP___EXPECTED_BAD_EXPECTED_ACCESS_H
69