Hi All,
I'm making a class which derives(impleme nts) from 5 interfaces:
class myClass: public base1, public base2, public base3,.......
I want to be able to ask from any interface about a pointer to another
interface
What I mean is:
myClass _myImpObj;
base1 *b1 = &_myImpObj;
base *b2 = b1->QueryInterafce ("b2");
base *b3 = b2->QueryInterafce ("b3");
base *b1N = b3->QueryInterface ("b1");
Its is very simialir to COM mechanism.Anyon e knows how to implement it?
Thanks,
Denis 4 1477
void* myClass::QueryI nterface(char* str)
{
if (!strcmp(str, "b1"))
return (base1*)this;
....
....
}
Is this what you meant?
denis wrote:
Hi All,
I'm making a class which derives(impleme nts) from 5 interfaces:
class myClass: public base1, public base2, public base3,.......
I want to be able to ask from any interface about a pointer to another
interface
What I mean is:
myClass _myImpObj;
base1 *b1 = &_myImpObj;
base *b2 = b1->QueryInterafce ("b2");
base *b3 = b2->QueryInterafce ("b3");
base *b1N = b3->QueryInterface ("b1");
Its is very simialir to COM mechanism.Anyon e knows how to implement it?
Thanks,
Denis
denis wrote:
Hi All,
I'm making a class which derives(impleme nts) from 5 interfaces:
class myClass: public base1, public base2, public base3,.......
I want to be able to ask from any interface about a pointer to another
interface
What I mean is:
myClass _myImpObj;
base1 *b1 = &_myImpObj;
base *b2 = b1->QueryInterafce ("b2");
base *b3 = b2->QueryInterafce ("b3");
base *b1N = b3->QueryInterface ("b1");
Its is very simialir to COM mechanism.Anyon e knows how to implement it?
You can use dynamic_cast:
#include <iostream>
template <int N>
struct base{
virtual ~base(){}
};
struct my12 : base<1>, base<2>{};
struct my34 : base<3>, base<4>{};
struct my5 : base<5>{};
struct my12345 : base<1>,base<2> , my34 ,my5{};
template <int N, typename T>
bool has_interface(T * t)
{
bool is = dynamic_cast< base<N* (t) !=0;
std::cout << typeid(T).name( ) << " "
<< ((is)?"Is":"Is not")<< " a base<" << N << ">\n";
return is;
}
template <int N>
struct interfaces;
template <>
struct interfaces<1>{
template <typename T>
void operator()( T * t)const
{
has_interface<1 >(t);
}
};
template <int N>
struct interfaces{
template <typename T>
void operator()( T * t)const
{
interfaces<N-1f;
f(t);
has_interface<N >(t);
}
};
int main()
{
//test 5 interfaces
interfaces<5tes t;
//test some expressions
my12 var12;
test(&var12);
std::cout <<"---------\n\n";
my34 var34;
test(&var34);
std::cout <<"---------\n\n";
my5 var5;
test(&var5);
std::cout <<"---------\n\n";
my12345 var12345;
test(&var12345) ;
}
regards
Andy Little
kwikius wrote:
//forgot crosscast test:
/*
....
*/
std::cout <<"---------\n\n";
my12345 var12345;
test(&var12345) ;
std::cout <<"---------\n\n";
//crosscast test
base<1>* bb = &var12345;
test(bb);
>
}
regards
Andy Little
On 14 Jan 2007 01:42:35 -0800, denis <de**********@h otmail.comwrote :
Hi All,
I'm making a class which derives(impleme nts) from 5 interfaces:
class myClass: public base1, public base2, public base3,.......
I want to be able to ask from any interface about a pointer to another
interface
What I mean is:
myClass _myImpObj;
base1 *b1 = &_myImpObj;
base *b2 = b1->QueryInterafce ("b2");
base *b3 = b2->QueryInterafce ("b3");
base *b1N = b3->QueryInterface ("b1");
Its is very simialir to COM mechanism.Anyon e knows how to implement it?
Not knowing what you want to accomplish, this sounds like a really bad idea.
Both the code itself, and the wish to emulate COM.
/Jorgen
--
// Jorgen Grahn <grahn@ Ph'nglui mglw'nafh Cthulhu
\X/ snipabacken.dyn dns.org R'lyeh wgah'nagl fhtagn! This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics |
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