c++ - Inheritance resolution -

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i thought types automatically resolve deepest part of hierarchy could. if cat : animal , call cat->talk(), if cat overrides talk() class animal, cat "meow", not weird general animal grumbling provided in base class animal.

so i'm confused this:

struct animal {   virtual void talkto( animal* o ) {     puts( "animal-animal" ) ;   } } ;  struct cat : public animal {   virtual void talkto( animal* o ) {     puts( "cat-animal" ) ;   }   virtual void talkto( cat* o ) {     puts( "cat says meow cat" ) ;   } } ;

here's calling code:

  cat *cat = new cat() ;   cat->talkto( cat ) ; //cat says meow cat    animal *animalcatptr = cat ;         cat->talkto( animalcatptr ) ; //cat-animal

the last line here, send cat cat->talkto, i'm using animalcatptr. animalcatptr still refers cat, yet resolving animal in function call.

how can make pass pointer resolve deepest type in hierarchy is? don't want series of dynamic_cast<> testing see if animal have on hand cat or dog or have you.

you want form of double-dispatch, see http://en.wikipedia.org/wiki/double_dispatch


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