Meaning of .clear() for containers

[so]

> clear as a global function is for destroying a class/struct
>
> clear as a member can do anything.  clear is not a keyword.
>
> clear(container) -> same as delete container, but without freeing any  
> memory.
>
> container.clear() -> remove all elements
>
> This has been brought up before as a problem, I'm not sure it's that  
> terrible, but I can see why there might be confusion.

Thanks for the example, this semantical issue was bugging me for a while  
(not the OOP vs whatever flamewar).

Is there a semantical difference between "function(obj)" and  
"obj.function()"?
If we are not clear on this simple thing, we should just stop here :)