libstdc++
exception_ptr.h
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00001 // Exception Handling support header (exception_ptr class) for -*- C++ -*-
00002 
00003 // Copyright (C) 2008-2015 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     /**
00072      *  @brief An opaque pointer to an arbitrary exception.
00073      *  @ingroup exceptions
00074      */
00075     class exception_ptr
00076     {
00077       void* _M_exception_object;
00078 
00079       explicit exception_ptr(void* __e) _GLIBCXX_USE_NOEXCEPT;
00080 
00081       void _M_addref() _GLIBCXX_USE_NOEXCEPT;
00082       void _M_release() _GLIBCXX_USE_NOEXCEPT;
00083 
00084       void *_M_get() const _GLIBCXX_NOEXCEPT __attribute__ ((__pure__));
00085 
00086       friend exception_ptr std::current_exception() _GLIBCXX_USE_NOEXCEPT;
00087       friend void std::rethrow_exception(exception_ptr);
00088 
00089     public:
00090       exception_ptr() _GLIBCXX_USE_NOEXCEPT;
00091 
00092       exception_ptr(const exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
00093 
00094 #if __cplusplus >= 201103L
00095       exception_ptr(nullptr_t) noexcept
00096       : _M_exception_object(0)
00097       { }
00098 
00099       exception_ptr(exception_ptr&& __o) noexcept
00100       : _M_exception_object(__o._M_exception_object)
00101       { __o._M_exception_object = 0; }
00102 #endif
00103 
00104 #if (__cplusplus < 201103L) || defined (_GLIBCXX_EH_PTR_COMPAT)
00105       typedef void (exception_ptr::*__safe_bool)();
00106 
00107       // For construction from nullptr or 0.
00108       exception_ptr(__safe_bool) _GLIBCXX_USE_NOEXCEPT;
00109 #endif
00110 
00111       exception_ptr& 
00112       operator=(const exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
00113 
00114 #if __cplusplus >= 201103L
00115       exception_ptr& 
00116       operator=(exception_ptr&& __o) noexcept
00117       {
00118         exception_ptr(static_cast<exception_ptr&&>(__o)).swap(*this);
00119         return *this;
00120       }
00121 #endif
00122 
00123       ~exception_ptr() _GLIBCXX_USE_NOEXCEPT;
00124 
00125       void 
00126       swap(exception_ptr&) _GLIBCXX_USE_NOEXCEPT;
00127 
00128 #ifdef _GLIBCXX_EH_PTR_COMPAT
00129       // Retained for compatibility with CXXABI_1.3.
00130       void _M_safe_bool_dummy() _GLIBCXX_USE_NOEXCEPT
00131         __attribute__ ((__const__));
00132       bool operator!() const _GLIBCXX_USE_NOEXCEPT
00133         __attribute__ ((__pure__));
00134       operator __safe_bool() const _GLIBCXX_USE_NOEXCEPT;
00135 #endif
00136 
00137 #if __cplusplus >= 201103L
00138       explicit operator bool() const
00139       { return _M_exception_object; }
00140 #endif
00141 
00142       friend bool 
00143       operator==(const exception_ptr&, const exception_ptr&)
00144         _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
00145 
00146       const class std::type_info*
00147       __cxa_exception_type() const _GLIBCXX_USE_NOEXCEPT
00148         __attribute__ ((__pure__));
00149     };
00150 
00151     bool 
00152     operator==(const exception_ptr&, const exception_ptr&)
00153       _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
00154 
00155     bool 
00156     operator!=(const exception_ptr&, const exception_ptr&)
00157       _GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
00158 
00159     inline void
00160     swap(exception_ptr& __lhs, exception_ptr& __rhs)
00161     { __lhs.swap(__rhs); }
00162 
00163   } // namespace __exception_ptr
00164 
00165 
00166   /// Obtain an exception_ptr pointing to a copy of the supplied object.
00167   template<typename _Ex>
00168     exception_ptr 
00169     make_exception_ptr(_Ex __ex) _GLIBCXX_USE_NOEXCEPT
00170     {
00171 #if __cpp_exceptions
00172       try
00173         {
00174           throw __ex;
00175         }
00176       catch(...)
00177         {
00178           return current_exception();
00179         }
00180 #else
00181       return exception_ptr();
00182 #endif
00183     }
00184 
00185   // _GLIBCXX_RESOLVE_LIB_DEFECTS
00186   // 1130. copy_exception name misleading
00187   /// Obtain an exception_ptr pointing to a copy of the supplied object.
00188   /// This function is deprecated, use std::make_exception_ptr instead.
00189   template<typename _Ex>
00190     exception_ptr
00191     copy_exception(_Ex __ex) _GLIBCXX_USE_NOEXCEPT _GLIBCXX_DEPRECATED;
00192 
00193   template<typename _Ex>
00194     exception_ptr
00195     copy_exception(_Ex __ex) _GLIBCXX_USE_NOEXCEPT
00196     { return std::make_exception_ptr<_Ex>(__ex); }
00197 
00198   // @} group exceptions
00199 } // namespace std
00200 
00201 } // extern "C++"
00202 
00203 #pragma GCC visibility pop
00204 
00205 #endif