libcxx/include/__cxx03/__expected/bad_expected_access.h

   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 <__cxx03/__config>
  13 #include <__cxx03/__exception/exception.h>
  14 #include <__cxx03/__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 <__cxx03/__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 _LIBCPP_DIAGNOSTIC_PUSH
  31 #  if !_LIBCPP_AVAILABILITY_HAS_BAD_EXPECTED_ACCESS_KEY_FUNCTION
  32 _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wweak-vtables")
  33 #  endif
  34 template <>
  35 class _LIBCPP_EXPORTED_FROM_ABI bad_expected_access<void> : public exception {
  36 protected:
  37   _LIBCPP_HIDE_FROM_ABI bad_expected_access() noexcept                                      = default;
  38   _LIBCPP_HIDE_FROM_ABI bad_expected_access(const bad_expected_access&) noexcept            = default;
  39   _LIBCPP_HIDE_FROM_ABI bad_expected_access(bad_expected_access&&) noexcept                 = default;
  40   _LIBCPP_HIDE_FROM_ABI bad_expected_access& operator=(const bad_expected_access&) noexcept = default;
  41   _LIBCPP_HIDE_FROM_ABI bad_expected_access& operator=(bad_expected_access&&) noexcept      = default;
  42   _LIBCPP_HIDE_FROM_ABI_VIRTUAL ~bad_expected_access() override                             = default;
  43
  44 public:
  45 #  if _LIBCPP_AVAILABILITY_HAS_BAD_EXPECTED_ACCESS_KEY_FUNCTION
  46   const char* what() const noexcept override;
  47 #  else
  48   _LIBCPP_HIDE_FROM_ABI_VIRTUAL const char* what() const noexcept override { return "bad access to std::expected"; }
  49 #  endif
  50 };
  51 _LIBCPP_DIAGNOSTIC_POP
  52
  53 template <class _Err>
  54 class bad_expected_access : public bad_expected_access<void> {
  55 public:
  56   _LIBCPP_HIDE_FROM_ABI explicit bad_expected_access(_Err __e) : __unex_(std::move(__e)) {}
  57
  58   _LIBCPP_HIDE_FROM_ABI _Err& error() & noexcept { return __unex_; }
  59   _LIBCPP_HIDE_FROM_ABI const _Err& error() const& noexcept { return __unex_; }
  60   _LIBCPP_HIDE_FROM_ABI _Err&& error() && noexcept { return std::move(__unex_); }
  61   _LIBCPP_HIDE_FROM_ABI const _Err&& error() const&& noexcept { return std::move(__unex_); }
  62
  63 private:
  64   _Err __unex_;
  65 };
  66
  67 _LIBCPP_END_NAMESPACE_STD
  68
  69 #endif // _LIBCPP_STD_VER >= 23
  70
  71 _LIBCPP_POP_MACROS
  72
  73 #endif // _LIBCPP___EXPECTED_BAD_EXPECTED_ACCESS_H