Should look like this: class Number { public: Number& operator++ () // prefix ++ { // Do work on this. (increment your object here) return *this; } // You want to make the ++ operator work like the standard operators // The simple way to do this is to implement postfix in terms of prefix. … Read more
Use ReferenceEquals: Foo foo1 = null; Foo foo2 = new Foo(); Assert.IsFalse(foo1 == foo2); public static bool operator ==(Foo foo1, Foo foo2) { if (object.ReferenceEquals(null, foo1)) return object.ReferenceEquals(null, foo2); return foo1.Equals(foo2); }
As you’ve found, JavaScript doesn’t support operator overloading. The closest you can come is to implement toString (which will get called when the instance needs to be coerced to being a string) and valueOf (which will get called to coerce it to a number, for instance when using + for addition, or in many cases … Read more
Overloadable Operators, from MSDN: Assignment operators cannot be overloaded, but +=, for example, is evaluated using +, which can be overloaded. Even more, none of assignment operators can be overloaded. I think this is because there will be an effect for the Garbage collection and memory management, which is a potential security hole in CLR … Read more
If you define your operator overloaded function as member function, then the compiler translates expressions like s1 + s2 into s1.operator+(s2). That means, the operator overloaded member function gets invoked on the first operand. That is how member functions work! But what if the first operand is not a class? There’s a major problem if … Read more
All design processes result in compromises between mutually incompatible goals. Unfortunately, the design process for the overloaded && operator in C++ produced a confusing end result: that the very feature you want from && — its short-circuiting behavior — is omitted. The details of how that design process ended up in this unfortunate place, those … Read more
According to the specification, TypeScript does support method overloading, but it’s quite awkward and includes a lot of manual work checking types of parameters. I think it’s mostly because the closest you can get to method overloading in plain JavaScript includes that checking too and TypeScript tries to not modify actual method bodies to avoid … Read more
-> This is the only really tricky one. It must be a nonstatic member function, and it takes no arguments. The return value is used to perform the member lookup. If the return value is another object of class type, not a pointer, then the subsequent member lookup is also handled by an operator-> function. … Read more
C++ inherits true blue operators from C. By that I mean that the “+” in 6 + 4 is very special. You can’t, for instance, get a pointer to that + function. Scala on the other hand doesn’t have operators in that way. It just has great flexibility in defining method names plus a bit … Read more
The problem here is in your interpretation of the article you link. Equality This article is about somebody that is having problems correctly defining the bool relationship operators. The operator: Equality == and != Relationship < > <= >= These operators should return a bool as they are comparing two objects of the same type. … Read more