What does the name after the closing class bracket means?

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庸人自扰
庸人自扰 2021-02-08 14:45

I\'ve encountered this code example and I remembered I\'ve seen it before and I didn\'t know what it is for and what it does? I\'ve searched on the internet but without luck.

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  •  天涯浪人
    2021-02-08 15:37

    } g_c;
    

    Here g_c is declared to be an object of the class type C.

    Such construct enables you to create object(s) of unnamed type as:

    class  //Nameless class!
    {
       //data members
    
    }obj1, obj2;
    

    In this example, obj1 and obj2 are declared to be objects of a class type which has not been given any name — the class is nameless! In such situation, you cannot declare objects in a conventional sense (i.e Type obj1, obj2; sense). So this construct helps you do that.

    You can even derive from other named classes while being nameless (and declaring the objects of the nameless class):

    class : public A, public B //Nameless class is deriving from A and B
    {
       //data members
    
    }obj1, obj2;
    

    In short, this construct ensures that the user wouldn't be able to create more objects than intended, unless some evil programmer uses/misuses/abuses C++11 (or template) as:

    decltype(obj1) obj3; //hehe!
    

    Hope that helps!

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