The OpenD Programming Language

Object.opEquals

Test whether this is equal to o. The default implementation only compares by identity (using the is operator). Generally, overrides and overloads for opEquals should attempt to compare objects by their contents. A class will most likely want to add an overload that takes your specific type as the argument and does the content comparison. Then you can override this and forward it to your specific typed overload with a cast. Remember to check for null on the typed overload.

class Object
bool
opEquals

Examples

class Child {
   int contents;
   // the typed overload first. It can use all the attribute you want
   bool opEquals(const Child c) const @safe pure nothrow @nogc
   {
       if (c is null)
           return false;
       return this.contents == c.contents;
   }

   // and now the generic override forwards with a cast
   override bool opEquals(Object o)
   {
       return this.opEquals(cast(Child) o);
   }
}

Meta