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digitalmars.D.learn - "new class" and accessing outer this

reply Henning Hasemann <hhasemann web.de> writes:
For those who don't know it: I'm talking here about the undocumented(?)
new class { } - feature. I.e. You can do the following:

class Foo {
 int bar() { return 5; }
}

auto x = new class Foo {
  int bar() { return 6; }
  int foo() { return 7; }
};

then x will hold an object of a class derived from Foo.


Say I have a contstruct like this:

class Dispatcher {
 // ...
}

class Base {
  Dispatcher dispatcher;
}

class Something : Base {
  this() {
    dispatcher = new class Dispatcher {
      void foo() {
        // XXX
      }
    };
  }
} // class Something


Now I want to access the "outer this" i.e. the instance of Something at
the line I marked with XXX. Is this possible without a temporary
variable that "renames" the outer this?
(simply 'this' would refer to the inner, i.e. the object foo is a
method of.)

Henning

-- 
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http://keyserver.ganneff.de:11371/pks/lookup?op=get&search=0xDDD6D36D41911851
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Jun 18 2007
next sibling parent Kirk McDonald <kirklin.mcdonald gmail.com> writes:
Henning Hasemann wrote:

 For those who don't know it: I'm talking here about the undocumented(?)
 new class { } - feature. I.e. You can do the following:
 
 class Foo {
  int bar() { return 5; }
 }
 
 auto x = new class Foo {
   int bar() { return 6; }
   int foo() { return 7; }
 };
 
 then x will hold an object of a class derived from Foo.
 
 
 Say I have a contstruct like this:
 
 class Dispatcher {
  // ...
 }
 
 class Base {
   Dispatcher dispatcher;
 }
 
 class Something : Base {
   this() {
     dispatcher = new class Dispatcher {
       void foo() {
         // XXX
       }
     };
   }
 } // class Something
 
 
 Now I want to access the "outer this" i.e. the instance of Something at
 the line I marked with XXX. Is this possible without a temporary
 variable that "renames" the outer this?
 (simply 'this' would refer to the inner, i.e. the object foo is a
 method of.)
 
 Henning
 



Nested class instances have an .outer property, for example:

class Something : Base {
   this() {
     dispatcher = new class Dispatcher {
       void foo() {
         this.outer.bar();
       }
     };
   }
   void bar() {}
}

-- 
Kirk McDonald
http://kirkmcdonald.blogspot.com
Pyd: Connecting D and Python
http://pyd.dsource.org
Jun 18 2007
prev sibling next sibling parent "Jarrett Billingsley" <kb3ctd2 yahoo.com> writes:
"Henning Hasemann" <hhasemann web.de> wrote in message 
news:20070618214023.53eb5058 amee...

 For those who don't know it: I'm talking here about the undocumented(?)
 new class { } - feature.



http://www.digitalmars.com/d/class.html#anonymous

:)
Jun 18 2007
prev sibling parent Henning Hasemann <hhasemann web.de> writes:
Am Mon, 18 Jun 2007 21:40:23 +0200
schrieb Henning Hasemann <hhasemann web.de>:


Thanks to both answerers, that was exactly what I looked for.
And sorry for my blindness ,-)

Henning

-- 
GPG Public Key:
http://keyserver.ganneff.de:11371/pks/lookup?op=get&search=0xDDD6D36D41911851
Fingerprint: 344F 4072 F038 BB9E B35D  E6AB DDD6 D36D 4191 1851
Jun 18 2007