1 // Nested Exception support header (nested_exception class) for -*- C++ -*-
3 // Copyright (C) 2009-2014 Free Software Foundation, Inc.
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
25 /** @file bits/nested_exception.h
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly. @headername{exception}
30 #ifndef _GLIBCXX_NESTED_EXCEPTION_H
31 #define _GLIBCXX_NESTED_EXCEPTION_H 1
33 #pragma GCC visibility push(default)
35 #if __cplusplus < 201103L
36 # include <bits/c++0x_warning.h>
39 #include <bits/c++config.h>
41 #if ATOMIC_INT_LOCK_FREE < 2
42 # error This platform does not support exception propagation.
50 * @addtogroup exceptions
54 /// Exception class with exception_ptr data member.
55 class nested_exception
60 nested_exception() noexcept
: _M_ptr(current_exception()) { }
62 nested_exception(const nested_exception
&) noexcept
= default;
64 nested_exception
& operator=(const nested_exception
&) noexcept
= default;
66 virtual ~nested_exception() noexcept
;
70 rethrow_nested() const
73 rethrow_exception(_M_ptr
);
78 nested_ptr() const noexcept
82 template<typename _Except
>
83 struct _Nested_exception
: public _Except
, public nested_exception
85 explicit _Nested_exception(const _Except
& __ex
)
89 explicit _Nested_exception(_Except
&& __ex
)
90 : _Except(static_cast<_Except
&&>(__ex
))
94 template<typename _Tp
,
95 bool __with_nested
= !__is_base_of(nested_exception
, _Tp
)>
96 struct _Throw_with_nested_impl
98 template<typename _Up
>
99 static void _S_throw(_Up
&& __t
)
100 { throw _Nested_exception
<_Tp
>{static_cast<_Up
&&>(__t
)}; }
103 template<typename _Tp
>
104 struct _Throw_with_nested_impl
<_Tp
, false>
106 template<typename _Up
>
107 static void _S_throw(_Up
&& __t
)
108 { throw static_cast<_Up
&&>(__t
); }
111 template<typename _Tp
, bool = __is_class(_Tp
)>
112 struct _Throw_with_nested_helper
: _Throw_with_nested_impl
<_Tp
>
115 template<typename _Tp
>
116 struct _Throw_with_nested_helper
<_Tp
, false>
117 : _Throw_with_nested_impl
<_Tp
, false>
120 template<typename _Tp
>
121 struct _Throw_with_nested_helper
<_Tp
&, false>
122 : _Throw_with_nested_helper
<_Tp
>
125 template<typename _Tp
>
126 struct _Throw_with_nested_helper
<_Tp
&&, false>
127 : _Throw_with_nested_helper
<_Tp
>
130 /// If @p __t is derived from nested_exception, throws @p __t.
131 /// Else, throws an implementation-defined object derived from both.
132 template<typename _Tp
>
135 throw_with_nested(_Tp
&& __t
)
137 _Throw_with_nested_helper
<_Tp
>::_S_throw(static_cast<_Tp
&&>(__t
));
140 template<typename _Tp
, bool = __is_polymorphic(_Tp
)>
141 struct _Rethrow_if_nested_impl
143 static void _S_rethrow(const _Tp
& __t
)
145 if (auto __tp
= dynamic_cast<const nested_exception
*>(&__t
))
146 __tp
->rethrow_nested();
150 template<typename _Tp
>
151 struct _Rethrow_if_nested_impl
<_Tp
, false>
153 static void _S_rethrow(const _Tp
&) { }
156 /// If @p __ex is derived from nested_exception, @p __ex.rethrow_nested().
157 template<typename _Ex
>
159 rethrow_if_nested(const _Ex
& __ex
)
161 _Rethrow_if_nested_impl
<_Ex
>::_S_rethrow(__ex
);
164 // @} group exceptions
171 #pragma GCC visibility pop
173 #endif // _GLIBCXX_NESTED_EXCEPTION_H