# typeinfo

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    00001 // RTTI support for -*- C++ -*-
    00002 // Copyright (C) 1994, 1995, 1996, 1997, 1998, 2000, 2001, 2002
    00003 // Free Software Foundation
    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 2, 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 // You should have received a copy of the GNU General Public License
    00018 // along with GCC; see the file COPYING.  If not, write to
    00019 // the Free Software Foundation, 59 Temple Place - Suite 330,
    00020 // Boston, MA 02111-1307, USA.
    00021
    00022 // As a special exception, you may use this file as part of a free software
    00023 // library without restriction.  Specifically, if other files instantiate
    00024 // templates or use macros or inline functions from this file, or you compile
    00025 // this file and link it with other files to produce an executable, this
    00026 // file does not by itself cause the resulting executable to be covered by
    00027 // the GNU General Public License.  This exception does not however
    00028 // invalidate any other reasons why the executable file might be covered by
    00029 // the GNU General Public License.
    00030
    00031 /** @file typeinfo
    00032  *  This header provides RTTI support.
    00033  */
    00034
    00035 #ifndef _TYPEINFO
    00036 #define _TYPEINFO
    00037
    00038 #include <exception>
    00039
    00040 extern "C++" {
    00041
    00042 namespace __cxxabiv1
    00043 {
    00044   class __class_type_info;
    00045 } // namespace __cxxabiv1
    00046
    00047 #if !__GXX_WEAK__
    00048   // If weak symbols are not supported, typeinfo names are not merged.
    00049   #define __GXX_MERGED_TYPEINFO_NAMES 0
    00050 #else
    00051   // On platforms that support weak symbols, typeinfo names are merged.
    00052   #define __GXX_MERGED_TYPEINFO_NAMES 1
    00053 #endif
    00054
    00055 namespace std
    00056 {
    00057   /**
    00058    *  @brief  Part of RTTI.
    00059    *
    00060    *  The @c type_info class describes type information generated by
    00061    *  an implementation.
    00062   */
    00063   class type_info
    00064   {
    00065   public:
    00066     /** Destructor. Being the first non-inline virtual function, this
    00067      *  controls in which translation unit the vtable is emitted. The
    00068      *  compiler makes use of that information to know where to emit
    00069      *  the runtime-mandated type_info structures in the new-abi.  */
    00070     virtual ~type_info();
    00071
    00072   private:
    00073     /// Assigning type_info is not supported.  Made private.
    00074     type_info& operator=(const type_info&);
    00075     type_info(const type_info&);
    00076
    00077   protected:
    00078     const char *__name;
    00079
    00080   protected:
    00081     explicit type_info(const char *__n): __name(__n) { }
    00082
    00083   public:
    00084     // the public interface
    00085     /** Returns an @e implementation-defined byte string; this is not
    00086      *  portable between compilers!  */
    00087     const char* name() const
    00088     { return __name; }
    00089
    00090 #if !__GXX_MERGED_TYPEINFO_NAMES
    00091     bool before(const type_info& __arg) const;
    00092     // In old abi, or when weak symbols are not supported, there can
    00093     // be multiple instances of a type_info object for one
    00094     // type. Uniqueness must use the _name value, not object address.
    00095     bool operator==(const type_info& __arg) const;
    00096 #else
    00097     /** Returns true if @c *this precedes @c __arg in the implementation's
    00098      *  collation order.  */
    00099     // In new abi we can rely on type_info's NTBS being unique,
    00100     // and therefore address comparisons are sufficient.
    00101     bool before(const type_info& __arg) const
    00102     { return __name < __arg.__name; }
    00103     bool operator==(const type_info& __arg) const
    00104     { return __name == __arg.__name; }
    00105 #endif
    00106     bool operator!=(const type_info& __arg) const
    00107     { return !operator==(__arg); }
    00108
    00109     // the internal interface
    00110   public:
    00111     // return true if this is a pointer type of some kind
    00112     virtual bool __is_pointer_p() const;
    00113     // return true if this is a function type
    00114     virtual bool __is_function_p() const;
    00115
    00116     // Try and catch a thrown type. Store an adjusted pointer to the
    00117     // caught type in THR_OBJ. If THR_TYPE is not a pointer type, then
    00118     // THR_OBJ points to the thrown object. If THR_TYPE is a pointer
    00119     // type, then THR_OBJ is the pointer itself. OUTER indicates the
    00120     // number of outer pointers, and whether they were const
    00121     // qualified.
    00122     virtual bool __do_catch(const type_info *__thr_type, void **__thr_obj,
    00123                 unsigned __outer) const;
    00124
    00125     // internally used during catch matching
    00126     virtual bool __do_upcast(const __cxxabiv1::__class_type_info *__target,
    00127                  void **__obj_ptr) const;
    00128   };
    00129
    00130   /**
    00131    *  @brief  Thrown during incorrect typecasting.
    00132    *
    00133    *  If you attempt an invalid @c dynamic_cast expression, an instance of
    00134    *  this class (or something derived from this class) is thrown.  */
    00135   class bad_cast : public exception
    00136   {
    00137   public:
    00138     bad_cast() throw() { }
    00139     // This declaration is not useless:
    00140     // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
    00141     virtual ~bad_cast() throw();
    00142   };
    00143
    00144   /** If you use a NULL pointer in a @c typeid expression, this is thrown.  */
    00145   class bad_typeid : public exception
    00146   {
    00147   public:
    00148     bad_typeid () throw() { }
    00149     // This declaration is not useless:
    00150     // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
    00151     virtual ~bad_typeid() throw();
    00152   };
    00153 } // namespace std
    00154
    00155 } // extern "C++"
    00156 #endif