• Michael Koehmstedt (3/3) Jul 04 2008 I just read this in the book "Learn to Tango with D", page 73:
• Kirk McDonald (16/24) Jul 04 2008 interface I {
• Michael Koehmstedt (2/30) Jul 05 2008
• Manfred_Nowak (3/4) Jul 05 2008 ... which can be understood as being different from what Michael cited.

Michael Koehmstedt <mykillk gmail.com> writes:

I just read this in the book "Learn to Tango with D", page 73:

"It is not possible to instantiate interfaces, but you can have references to
class instances through the type of an interface that the class implements."

Could anyone give an example of what this means?

Kirk McDonald <kirklin.mcdonald gmail.com> writes:

Michael Koehmstedt wrote:
 I just read this in the book "Learn to Tango with D", page 73:
 
 "It is not possible to instantiate interfaces, but you can have references to
class instances through the type of an interface that the class implements."
 
 Could anyone give an example of what this means?
 
 
 

interface I {
     void foo();
}

class C : I {
     override void foo() {}
}

void main() {
     I i = new C; // reference to class instance of interface type
     i.foo();
}

-- 
Kirk McDonald
http://kirkmcdonald.blogspot.com
Pyd: Connecting D and Python
http://pyd.dsource.org

Michael Koehmstedt <mykillk gmail.com> writes:

Thanks Kirk, a simple example is worth a thousand words!

Kirk McDonald Wrote:

 Michael Koehmstedt wrote:
 I just read this in the book "Learn to Tango with D", page 73:
 
 "It is not possible to instantiate interfaces, but you can have references to
class instances through the type of an interface that the class implements."
 
 Could anyone give an example of what this means?
 
 
 

 
 interface I {
      void foo();
 }
 
 class C : I {
      override void foo() {}
 }
 
 void main() {
      I i = new C; // reference to class instance of interface type
      i.foo();
 }
 
 -- 
 Kirk McDonald
 http://kirkmcdonald.blogspot.com
 Pyd: Connecting D and Python
 http://pyd.dsource.org

"Manfred_Nowak" <svv1999 hotmail.com> writes:

Kirk McDonald wrote:

 // reference to class instance of interface type

... which can be understood as being different from what Michael cited.

-manfred