A prescindere da skynet,se tu stai scrivendo il codice,tu sai che cosa punta il puntatore!
Tu hai creato il puntatore e solo tu hai creato l'assegnazione e quindi penso tu sappia bene a cosa stia puntando.
Se devi creare un puntatore generico allora devi crearti una variabile che indichi cosa esso contenga in base alle specifiche del tuo programma:
typedef struct _VARIANTPTR
{
void* var;
unsigned int size;
}VARIANTPTR;
int main()
{
int a=970;
double b=999.25;
VARIANTPTR c[2];
c[0].var=&a;
c[0].size=sizeof(a);
c[1].var=&b;
c[1].size=sizeof(b);
int i;
for (i=0; i < 2 ; i++)
{
if (c[i].size == 4)
{
printf ("c[%d]==%d\n",i,*((int*)c[i].var));
}
else if (c[i].size == 8)
{
printf ("c[%d]==%lf\n",i,*((double*)c[i].var));
}
}
return 0;
}
naturalmente una lettura al typeinfo.h non farebbe male:
// RTTI support for -*- C++ -*-
// Copyright (C) 1994, 1995 Free Software Foundation
// This file is part of the GNU ANSI C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this library; see the file COPYING. If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
// As a special exception, if you link this library with files
// compiled with a GNU compiler to produce an executable, this does not cause
// the resulting executable to be covered by the GNU General Public License.
// This exception does not however invalidate any other reasons why
// the executable file might be covered by the GNU General Public License.
// Written by Kung Hsu based upon the specification in the 20 September 1994
// C++ working paper, ANSI document X3J16/94-0158.
#ifndef __TYPEINFO__
#define __TYPEINFO__
#ifdef __GNUG__
#pragma interface "std/typeinfo.h"
#endif
extern "C" void* __throw_type_match_rtti (void *, void *, void *);
extern "C++" {
class type_info {
private:
// assigning type_info is not supported. made private.
type_info& operator=(const type_info&);
type_info(const type_info&);
public:
enum node_type {
_RTTI_BUILTIN_TYPE, // builtin type
_RTTI_USER_TYPE, // user defined type
_RTTI_CLASS_TYPE, // class type
_RTTI_POINTER_TYPE, // pointer type
_RTTI_ATTR_TYPE, // attribute type for const and volatile
_RTTI_FUNC_TYPE, // function type
_RTTI_PTMF_TYPE, // pointer to member function type
_RTTI_PTMD_TYPE // pointer to member data type
};
// return node type of the object
virtual node_type __rtti_get_node_type() const { return _RTTI_BUILTIN_TYPE; }
// get_name will return the name of the type, NULL if no name (like builtin)
virtual const char * __rtti_get_name() const { return 0; }
// compare if type represented by the type_info are the same type
virtual int __rtti_compare(const type_info&) const { return 0; }
// argument passed is the desired type,
// for class type, if the type can be converted to the desired type,
// it will be, and returned, else 0 is returned. If the match
// succeeds, the return value will be adjusted to point to the sub-object.
virtual void* __rtti_match(const type_info&, int, void *) const {
// This should never be called.
return 0;
};
// destructor
virtual ~type_info() {}
type_info() {}
bool before(const type_info& arg);
const char* name() const
{ return __rtti_get_name(); }
bool operator==(const type_info& arg) const
{ return __rtti_compare(arg) == 0; }
bool operator!=(const type_info& arg) const
{ return __rtti_compare(arg) != 0; }
};
// type_info for builtin type
class __builtin_type_info : public type_info {
public:
enum builtin_type_val {
_RTTI_BI_BOOL = 1, _RTTI_BI_CHAR, _RTTI_BI_SHORT, _RTTI_BI_INT,
_RTTI_BI_LONG, _RTTI_BI_LONGLONG, _RTTI_BI_FLOAT,
_RTTI_BI_DOUBLE, _RTTI_BI_LDOUBLE, _RTTI_BI_UCHAR,
_RTTI_BI_USHORT, _RTTI_BI_UINT, _RTTI_BI_ULONG,
_RTTI_BI_ULONGLONG, _RTTI_BI_SCHAR, _RTTI_BI_WCHAR, _RTTI_BI_VOID
};
builtin_type_val b_type;
__builtin_type_info (builtin_type_val bt) : b_type (bt) {}
node_type __rtti_get_node_type () const
{ return _RTTI_BUILTIN_TYPE; }
const char *__rtti_get_name () const
{ return (const char *)0; }
int __rtti_compare (const type_info& arg) const
{ return (arg.__rtti_get_node_type () == _RTTI_BUILTIN_TYPE &&
((__builtin_type_info&)arg).b_type == b_type) ? 0 : -1; }
};
// serice function for comparing types by name.
inline int __fast_compare (const char *n1, const char *n2) {
int c;
if (n1 == n2) return 0;
if (n1 == 0) return *n2;
else if (n2 == 0) return *n1;
c = (int)*n1++ - (int)*n2++;
return c == 0 ? strcmp (n1, n2) : c;
};
// type_info for user type.
class __user_type_info : public type_info {
private:
const char *_name;
public:
__user_type_info (const char *nm) : _name (nm) {}
node_type __rtti_get_node_type () const
{ return _RTTI_USER_TYPE; }
const char *__rtti_get_name () const
{ return _name; }
int __rtti_compare (const type_info& arg) const
{ return (arg.__rtti_get_node_type () == __rtti_get_node_type() &&
__fast_compare (_name, arg.__rtti_get_name ()) == 0) ? 0 : -1; }
};
// type_info for a class.
class __class_type_info : public __user_type_info {
private:
enum access_mode {
_RTTI_ACCESS_PUBLIC, _RTTI_ACCESS_PROTECTED, _RTTI_ACCESS_PRIVATE
};
type_info **base_list;
int *offset_list;
int *is_virtual_list;
access_mode *access_list;
int n_bases;
public:
__class_type_info (const char *name, type_info **bl, int *off,
int *is_vir, access_mode *acc, int bn)
: __user_type_info (name), base_list (bl), offset_list(off),
is_virtual_list(is_vir), access_list(acc), n_bases (bn) {}
node_type __rtti_get_node_type () const
{ return _RTTI_CLASS_TYPE; }
// inherit __rtti_compare from __user_type_info
// This is a little complex defined in typeinfo.cc
void* __rtti_match(const type_info&, int, void *) const;
};
// type info for pointer type.
class __pointer_type_info : public type_info {
private:
type_info& type;
public:
__pointer_type_info (type_info& ti) : type (ti) {}
node_type __rtti_get_node_type () const
{ return _RTTI_POINTER_TYPE; }
const char *__rtti_get_name () const
{ return (const char *)0; }
int __rtti_compare (const type_info& arg) const
{ return (arg.__rtti_get_node_type () == __rtti_get_node_type() &&
type.__rtti_compare ( ((__pointer_type_info&)arg).type) == 0) ? 0 : -1; }
void* __rtti_match(const type_info& catch_type, int, void *objptr) const;
};
// type info for attributes
class __attr_type_info : public type_info {
public:
enum attr_val {
_RTTI_ATTR_CONST = 1, _RTTI_ATTR_VOLATILE, _RTTI_ATTR_CONSTVOL
};
attr_val attr;
type_info& type;
__attr_type_info (attr_val a, type_info& t) : attr (a), type(t) {}
node_type __rtti_get_node_type () const
{ return _RTTI_ATTR_TYPE; }
const char *__rtti_get_name () const
{ return (const char *)0; }
int __rtti_compare (const type_info& arg) const
{ return (arg.__rtti_get_node_type () == _RTTI_ATTR_TYPE &&
attr == ((__attr_type_info&)arg).attr &&
type.__rtti_compare ( ((__attr_type_info&)arg).type ) == 0)
? 0 : -1; }
};
// type info for function.
class __func_type_info : public __user_type_info {
public:
__func_type_info (const char *name) : __user_type_info (name) {}
node_type __rtti_get_node_type () const
{ return _RTTI_FUNC_TYPE; }
};
// type info for pointer to member function.
class __ptmf_type_info : public __user_type_info {
public:
__ptmf_type_info (const char *name) : __user_type_info (name) {}
node_type __rtti_get_node_type () const
{ return _RTTI_PTMF_TYPE; }
};
// type info for pointer to data member.
class __ptmd_type_info : public type_info {
type_info& classtype;
type_info& type;
public:
__ptmd_type_info (type_info& tc, type_info& t) : classtype (tc), type (t) {}
node_type __rtti_get_node_type () const
{ return _RTTI_PTMD_TYPE; }
int __rtti_compare (const type_info& arg) const
{ return (arg.__rtti_get_node_type () == _RTTI_PTMD_TYPE &&
classtype.__rtti_compare ( ((__ptmd_type_info&)arg).classtype ) == 0 &&
type.__rtti_compare ( ((__ptmd_type_info&)arg).type ) == 0)
? 0 : -1; }
};
} // extern "C++"
#include <stdexcep>
#endif