On Monday, 7 October 2013 at 22:57:17 UTC, Ali Çehreli wrote:
On 10/07/2013 03:52 PM, Agustin wrote:
On Monday, 7 October 2013 at 19:59:09 UTC, Agustin wrote:
On Monday, 7 October 2013 at 19:58:21 UTC, Agustin wrote:
I'm having a hard time trying to use "scoped".
public T callEvent(T, A...)(auto ref A args) const
{
T pEvent = scoped!T(forward!args);
postEvent(pEvent, typeid(T).toHash);
return pEvent;
}
private void postEvent(ref Event event, Event.ID type) const
{
....
}
src\event\EventManager.d(37): Error: function
ghrum.event.EventManager.EventManager.postEvent (ref Event
event,
uint type) const is not callable using argument types
(MyEvent,uint)
src\event\EventManager.d(37): Error: function
ghrum.event.EventManager.EventManager.postEvent (ref Event
event,
uint type) const is not callable using argument types
(MyEvent,uint)
const
src\event\EventManager.d(37): Error: cast(Event)pEvent is
not an lvalue
callEvent!MyEvent(); Being MyEvent a subclass of Event.
So i found out that i cannot do this, may i ask why?
public class A
{
int x = 0;
}
public class B : A
{
}
void func(ref A a)
{
}
void main()
{
B b = new B();
func(b);
}
Since classes are already references, you would normally pass
A, not 'ref A'.
If you really want to pass 'ref A', perhaps you want to change
the actual object that an A is referring to:
public class C : A
{}
void func(ref A a)
{
a = new C; // <-- A reason for taking 'ref A'
}
However, that would upset the caller, which thinks it has a
reference to a B object:
void main()
{
B b = new B();
func(b); // <-- Oops! Not a B anymore?
}
Ali
Doesn't ref means i'm passing the parameter by reference instead
of by value?. Isn't "a" being copied when calling func?, or does
D always pass by reference when using classes and structures?
