Re: Restrict to objects with static storage duration
On Mar 27, 7:09 pm, "Victor Bazarov" <v.Abaza...@comAcast.net> wrote:
I am drawing a blank here...
Is there a way to restrict a class to only instantiate objects with
static storage duration, but no dynamic, and no automatic (hence no
function arguments, either) storage duration?
Disabling dynamic is easy (relatively), just make 'op new' private.
But automatic?
class AllowsOnlyStatics {
???
};
AllowsOnlyStatics OK;
class Other {
AllowsOnlyStatics notOK; // not sure about this one
};
int main() {
static AllowsOnlyStatics OKaswell;
AllowsOnlyStatics notOK; // should produce an error
Other o; // should also produc=
e an error
}
Any ideas?
How well it works for you, I am not sure. So, feel free to throw this
into the nearest garbage can. :-)
template<typename T, int i>
T& getStaticObject();
class OnlyStatic
{
private:
OnlyStatic(){std::cout << "ctor\n";}
OnlyStatic(const OnlyStatic&);
~OnlyStatic(){}
template<typename T, int i>
friend T& getStaticObject();
};
template<typename T, int i>
T& getStaticObject()
{
static T t;
return t;
}
int main()
{
OnlyStatic& osobj = getStaticObject<OnlyStatic,1>();
OnlyStatic& osobj2 = getStaticObject<OnlyStatic,2>();
}
There can be variants with getStaticObject as static member or a class
on its own. What I am trying to exploit is that each different
template instantiation would have its own copy of static data.