how to replace function-scoped static singleton

[Bob Doe]

Hello,

how to I replace singleton classes using function scope static
variables with one that doesn't use function scope static variables?:

class Foo {
public:
static Foo &instance();
virtual ~Foo();
...
private:
Foo();
Foo(const Foo&);
Foo & operator=(const Foo&);
};

----------------------------------
Foo &Foo::instance()
{
static Foo& theInstance;
...
return theInstance;
}

 

[James Kanze]

Not much point to have public virtual dtor for a singleton object which
is never destroyed ;-) But it does not hurt, of course.


This won't compile.

Function scope static variables are a proven method for creating
singletons. If this does not work for you, you should provide some
explanation about your worries (e.g. multithreading concerns, memory leak
alarms, etc...)

Paavo