hash_set equal function

[Marco Correia]

Please ignore the post, I found out the solution. Equal objects must have the 
same hash value...

Marco

On Friday 04 March 2005 20:07, Marco Correia wrote:
> Hi,
>
> Could anyone please tell me why the user defined equal function never gets
> called in the following code example?
>
>
> #include <iostream>
> #include <sstream>
> #include <ext/hash_set>
>
> using namespace std;
> using namespace __gnu_cxx;
>
> struct base
> {};
>
> struct derived : public base
> {};
>
> struct hash_fun
> {
>     size_t operator()(const base* e) const
>     { return (size_t)e; }
> };
>
> struct equal_fun
> {
>     size_t operator()(const base* e1, const base* e2) const
>     {
>         cout << "here" << endl; // this never gets printed
>         return 1;
>     }
> };
>
> int main()
> {
>     hash_set<base*,hash_fun,equal_fun> m;
>     derived* d1 = new derived();
>     derived* d2 = new derived();
>     m.insert(d1);
>     cout << (m.find(d2)==m.end()) << endl; // should call
> equal_fun::operator() ?
> }
>
> Thanks!
> Marco
> PS: Please email me directly since I'm not subscribed.
>
> -- Marco Correia <mvc@netcabo.pt>

-- 
Marco Correia <mvc@netcabo.pt>