From kde-devel  Sat Aug 19 02:12:37 2006
From: Craig Howard <kde () choward ! ca>
Date: Sat, 19 Aug 2006 02:12:37 +0000
To: kde-devel
Subject: Re: questions about c++ templates
Message-Id: <200608181912.37119.kde () choward ! ca>
X-MARC-Message: https://marc.info/?l=kde-devel&m=115595371617020

On Friday 18 August 2006 14:09, Kleag wrote:
> Well, with this code, templates have no influence, at least for nm: with or
> without them, there is no difference except for addresses.

Right, but that's significant, because Child::pure() wasn't referenced, so it 
shouldn't have been created.  Or so I thought.

> -0804894a W Base::Base()
> +080489ee W Base::Base()
>  08048920 W Base::~Base()
>  080488f6 W Base::~Base()
>  080488cc W Base::~Base()
> -080489ec W Child<int>::g()
> -08048a1a W Child<int>::pure()
> -0804895a W Child<int>::Child()
> -080489b4 W Child<int>::~Child()
> -0804897c W Child<int>::~Child()
> +080489c0 W Child::g()
> +080489ba W Child::pure()
> +080489fe W Child::Child()
> +08048982 W Child::~Child()
> +0804894a W Child::~Child()
>
> Regards,
>
> Kleag
>
> Le vendredi 18 août 2006 21:13, Craig Howard a écrit :
> > On Friday 18 August 2006 11:03, Frans Englich wrote:
> > Interesting.  You are correct:
> >
> > #include <iostream>
> >
> > using namespace std;
> >
> > class Base
> > {
> >     public:
> >         virtual ~Base() {}
> >
> >         virtual void pure() = 0;
> > };
> >
> > template<typename T>
> > class Child : public Base
> > {
> >     public:
> >         virtual ~Child() {}
> >
> >         virtual void pure() {}
> >         void g() { cout << "T1" << endl; }
> > };
> >
> > int main()
> > {
> >     Child<int> c;
> >
> >     c.g();
> >
> >     return 0;
> > }
> >
> >
> > 12:11:38 [21]; nm -C ./a.out | grep Child
> > 080489ba W Child<int>::g()
> > 080488de W Child<int>::pure()
> > 080488c0 W Child<int>::Child()
> > 0804890a W Child<int>::~Child()
> > 08048988 W Child<int>::~Child()
> > 08048b14 V typeinfo for Child<int>
> > 08048b20 V typeinfo name for Child<int>
> > 08048b00 V vtable for Child<int>
> >
> > Does anybody know why that is?  And why there are two destructors for
> > Child?

-- 

Craig Howard
craig@choward.ca
Software Engineer - Amazon.com
BMath CompSci - University of Waterloo
 
>> Visit http://mail.kde.org/mailman/listinfo/kde-devel#unsub to unsubscribe <<