Re: Assign Reference to another Referance

From:
Paavo Helde <paavo@nospam.please.ee>
Newsgroups:
comp.lang.c++
Date:
Thu, 24 Sep 2009 23:55:50 -0500
Message-ID:
<Xns9C9150AD0748Enobodyebiee@216.196.109.131>
cpisz <cpisz@austin.rr.com> kirjutas:

On Sep 24, 4:37?pm, Paavo Helde <pa...@nospam.please.ee> wrote:

cpisz <cp...@austin.rr.com> kirjutas:

a reference around instead. Singletons have caused more

problems than

they are worth in the past, with release order in program


exit.

That's why singletons are often created dynamically and not
destroyed before program exit.

Paavo


I've never in all my reading seen a singleton pattern that did not
involve a global or static pointer, or reference, and thus involve
problems of dependency at program exit time when these are released.
Could you share this pattern that side steps the problem?


See eg.

http://groups.google.com/group/comp.lang.c++/browse_thread/thread/bca4044
f40befc6a

Basically this comes down to:

class Singleton {
public:
     static Singleton& Instance();
     // ...
};

Singleton& Singleton::Instance() {
     static Singleton* the_singleton = new Singleton();
     return *singleton;
}

The static pointer is released at program exit, but the singleton itself
is never destroyed and remains intact until process exit. See the above
link for discussions of pros and cons.

Paavo

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