Thread: uncomfortable syntax

hi, cin is a iostream object . so i could use a member function for acessing the object.

i.e it is valid to write cin.get() // as get() is a member function



but how this is valid if i write....

int x;
cin>>x // surely " >>" is not a member function. how can i use this way ? is not it violating the acesses rule ? still it works..why?




another question > how much it is important to close the file stream ? i have seen if i dont close the stream it really does not matter....no compile error.

Originally Posted by blue_gene

int x;
cin>>x // surely " >>" is not a member function. how can i use this way ? is not it violating the acesses rule ? still it works..why?

the ">>" is the bitshift operator....so all you'd do, while creating the cin class/object, would be something like:

Code:

class cin
{
 public:
  operator >>;
}

I'm not sure if that's 100% correct, but it's close to it.

another question > how much it is important to close the file stream ? i have seen if i dont close the stream it really does not matter....no compile error.

No compiler error because the compiler doesn't care if it's closed or not. It's very important to close it though. Memory leaks, unable to access other files, etc... will PROBABLY occur if you don't close it.

your first answer is not supportive.... as i found references in many places ">>" has been usued as a operator overloading in this context.

probabily here it is not usued as a bitshift operator.

but still i can argue that it is not a member function.... so i can not acess that way.

what rule is governing here?

one more thing cin is an object , not a class ,as you have shown in your code.

In this context, >> and << are the insertion and extraction operators. They are the overloaded versions of the bitshift operators.

That is, they have a special meaning/function which has nothing to do with bit shifting, when they are used in the iostream context.

[EDIT] - I'm not sure if this helps, but operator overloading is really just another way of writing/calling a function.

[EDIT 2] - Closing a file: The compiler doesn't (always) know when or if you close the file. You might have several different places in your code where the file is closed under certain conditions. Or, you code might have a bug (a logical error, not a syntax error), that causes the close-file part of your program to be skipped.

In this context, >> and << are the insertion and extraction operators. They are the overloaded versions of the bitshift operators

ok.....i understand the point.

in fact, i felt it as a odd looking syntax here , as normally objects are not treated like that.

however, well, i have to obey the syntax.

thanks