Guaranteeing only one instantiation of a class

The question I'm working on is: Create a class that represents a printer connection, and that only allows you to have one printer.

Can someone give me a clue as to how to implement a class that limits the number of instantiations? I thought of having a class member which I can set to "false" if the static counter is already at 1, but this means the failed object nonetheless exists and seems messy since the client has to test the state of the object on their end. Better to have the object abort its own construction if there is already one in existence. But how do I go about doing this? Clue needed!

I don't know is it the correct method to use.
But you can always use a special constructor function which live outside the scope of the class.

for example

Code:

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TheObject & createTheObject()
{
    static TheObject theobj = new TheObject();

    return theobj;
}

---

it will only create the object once no matter how many times you call the function :)

Do a search for the Singleton Design Pattern.

Both good ideas, thanks! I'm reading about the Singleton pattern now. Although I'm not sure it's the solution the author of the book I'm using had in mind at this stage.

Quote:

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I thought of having a class member which I can set to "false" if the static counter is already at 1, but this means the failed object nonetheless exists and seems messy since the client has to test the state of the object on their end.

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This might also work, but you could throw an exception: the failed object would not exist and the user wouldn't need to test object (just handle the errors).