Here sys is a namespace.
If we use sys::xx, I know exactly the meaning of ::, but I saw a code, it's using
::sys::xx;
what's the meaning by putting :: before a namespace?
Here sys is a namespace.
If we use sys::xx, I know exactly the meaning of ::, but I saw a code, it's using
::sys::xx;
what's the meaning by putting :: before a namespace?
It means: look in the global namespace (::) for something named sys. Then look in that scope (class/struct/namespace) for something called xx.