What's actually going on in this AnonymousClass(variable) declaration?

Question

Trying to compile:

class AnonymousClass
{
public:
    AnonymousClass(int x)
    {
    }
};


int main()
{
    int x;
    AnonymousClass(x);
    return 0;
} 
         


        

Answer 1

You're missing an actual name for your variable/object:

AnonymousClass myclass(x);

Instead of that you could as well write...

AnonymousClass (myclass)(x);

So your line of code results in this:

AnonymousClass (x);

Or more common:

AnonymousClass x;

Why it happens? Brackets are just there for logical grouping ("what belongs together?"). The only difference is, they're forced for arguments (i.e. you can't just write AnonymousClass myclass x).