libstdc++
exception_ptr.h
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00001 // Exception Handling support header (exception_ptr class) for -*- C++ -*-
00002 
00003 // Copyright (C) 2008-2016 Free Software Foundation, Inc.
00004 //
00005 // This file is part of GCC.
00006 //
00007 // GCC is free software; you can redistribute it and/or modify
00008 // it under the terms of the GNU General Public License as published by
00009 // the Free Software Foundation; either version 3, or (at your option)
00010 // any later version.
00011 // 
00012 // GCC is distributed in the hope that it will be useful,
00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015 // GNU General Public License for more details.
00016 // 
00017 // Under Section 7 of GPL version 3, you are granted additional
00018 // permissions described in the GCC Runtime Library Exception, version
00019 // 3.1, as published by the Free Software Foundation.
00020 
00021 // You should have received a copy of the GNU General Public License and
00022 // a copy of the GCC Runtime Library Exception along with this program;
00023 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
00024 // <http://www.gnu.org/licenses/>.
00025 
00026 /** @file bits/exception_ptr.h
00027  *  This is an internal header file, included by other library headers.
00028  *  Do not attempt to use it directly. @headername{exception}
00029  */
00030 
00031 #ifndef _EXCEPTION_PTR_H
00032 #define _EXCEPTION_PTR_H
00033 
00034 #pragma GCC visibility push(default)
00035 
00036 #include <bits/c++config.h>
00037 #include <bits/exception_defines.h>
00038 
00039 #if ATOMIC_INT_LOCK_FREE < 2
00040 #  error This platform does not support exception propagation.
00041 #endif
00042 
00043 extern "C++" {
00044 
00045 namespace std 
00046 {
00047   class type_info;
00048 
00049   /**
00050    * @addtogroup exceptions
00051    * @{
00052    */
00053   namespace __exception_ptr
00054   {
00055     class exception_ptr;
00056   }
00057 
00058   using __exception_ptr::exception_ptr;
00059 
00060   /** Obtain an exception_ptr to the currently handled exception. If there
00061    *  is none, or the currently handled exception is foreign, return the null
00062    *  value.
00063    */
00064   exception_ptr current_exception() _GLIBCXX_USE_NOEXCEPT;
00065 
00066   /// Throw the object pointed to by the exception_ptr.
00067   void rethrow_exception(exception_ptr) __attribute__ ((__noreturn__));
00068 
00069   namespace __exception_ptr
00070   {
00071     using std::rethrow_exception;
00072 
00073     /**
00074      *  @brief An opaque pointer to an arbitrary exception.
00075      *  @ingroup exceptions
00076      */
00077     class exception_ptr
00078     {
00079       void* _M_exception_object;
00080 
00081       explicit exception_ptr(void* __e) _GLIBCXX_USE_NOEXCEPT;
00082 
00083       void _M_addref() _GLIBCXX_USE_NOEXCEPT;
00084       void _M_release() _GLIBCXX_USE_NOEXCEPT;
00085 
00086       void *_M_get() const _GLIBCXX_NOEXCEPT __attribute__ ((__pure__));
00087 
00088       friend exception_ptr std::current_exception() _GLIBCXX_USE_NOEXCEPT;
00089       friend void std::rethrow_exception(exception_ptr);
00090 
00091     public:
00092       exception_ptr() _GLIBCXX_USE_NOEXCEPT;
00093 
00094       exception_ptr(const exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
00095 
00096 #if __cplusplus >= 201103L
00097       exception_ptr(nullptr_t) noexcept
00098       : _M_exception_object(0)
00099       { }
00100 
00101       exception_ptr(exception_ptr&& __o) noexcept
00102       : _M_exception_object(__o._M_exception_object)
00103       { __o._M_exception_object = 0; }
00104 #endif
00105 
00106 #if (__cplusplus < 201103L) || defined (_GLIBCXX_EH_PTR_COMPAT)
00107       typedef void (exception_ptr::*__safe_bool)();
00108 
00109       // For construction from nullptr or 0.
00110       exception_ptr(__safe_bool) _GLIBCXX_USE_NOEXCEPT;
00111 #endif
00112 
00113       exception_ptr& 
00114       operator=(const exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
00115 
00116 #if __cplusplus >= 201103L
00117       exception_ptr& 
00118       operator=(exception_ptr&& __o) noexcept
00119       {
00120         exception_ptr(static_cast<exception_ptr&&>(__o)).swap(*this);
00121         return *this;
00122       }
00123 #endif
00124 
00125       ~exception_ptr() _GLIBCXX_USE_NOEXCEPT;
00126 
00127       void 
00128       swap(exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
00129 
00130 #ifdef _GLIBCXX_EH_PTR_COMPAT
00131       // Retained for compatibility with CXXABI_1.3.
00132       void _M_safe_bool_dummy() _GLIBCXX_USE_NOEXCEPT
00133         __attribute__ ((__const__));
00134       bool operator!() const _GLIBCXX_USE_NOEXCEPT
00135         __attribute__ ((__pure__));
00136       operator __safe_bool() const _GLIBCXX_USE_NOEXCEPT;
00137 #endif
00138 
00139 #if __cplusplus >= 201103L
00140       explicit operator bool() const
00141       { return _M_exception_object; }
00142 #endif
00143 
00144       friend bool 
00145       operator==(const exception_ptr&, const exception_ptr&)
00146         _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
00147 
00148       const class std::type_info*
00149       __cxa_exception_type() const _GLIBCXX_USE_NOEXCEPT
00150         __attribute__ ((__pure__));
00151     };
00152 
00153     bool 
00154     operator==(const exception_ptr&, const exception_ptr&)
00155       _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
00156 
00157     bool 
00158     operator!=(const exception_ptr&, const exception_ptr&)
00159       _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
00160 
00161     inline void
00162     swap(exception_ptr& __lhs, exception_ptr& __rhs)
00163     { __lhs.swap(__rhs); }
00164 
00165   } // namespace __exception_ptr
00166 
00167 
00168   /// Obtain an exception_ptr pointing to a copy of the supplied object.
00169   template<typename _Ex>
00170     exception_ptr 
00171     make_exception_ptr(_Ex __ex) _GLIBCXX_USE_NOEXCEPT
00172     {
00173 #if __cpp_exceptions
00174       try
00175         {
00176           throw __ex;
00177         }
00178       catch(...)
00179         {
00180           return current_exception();
00181         }
00182 #else
00183       return exception_ptr();
00184 #endif
00185     }
00186 
00187   // _GLIBCXX_RESOLVE_LIB_DEFECTS
00188   // 1130. copy_exception name misleading
00189   /// Obtain an exception_ptr pointing to a copy of the supplied object.
00190   /// This function is deprecated, use std::make_exception_ptr instead.
00191   template<typename _Ex>
00192     exception_ptr
00193     copy_exception(_Ex __ex) _GLIBCXX_USE_NOEXCEPT _GLIBCXX_DEPRECATED;
00194 
00195   template<typename _Ex>
00196     exception_ptr
00197     copy_exception(_Ex __ex) _GLIBCXX_USE_NOEXCEPT
00198     { return std::make_exception_ptr<_Ex>(__ex); }
00199 
00200   // @} group exceptions
00201 } // namespace std
00202 
00203 } // extern "C++"
00204 
00205 #pragma GCC visibility pop
00206 
00207 #endif