Implementing equality in .NET correctly, efficiently and without code duplication is hard. Specifically, for reference types with value semantics (i.e. immutable types that treat equvialence as equality), you should implement the System.IEquatable<T> interface, and you should implement all the different operations (Equals, GetHashCode and ==, !=). As an example, here’s a class implementing value equality: … Read more
I think the best you’d be able to do is use IConvertible as a constraint and do something like: public static operator T +(T x, T y) where T: IConvertible { var type = typeof(T); if (type == typeof(String) || type == typeof(DateTime)) throw new ArgumentException(String.Format(“The type {0} is not supported”, type.FullName), “T”); try { … Read more
As far as I’m aware, Javascript (at least as it exists now) doesn’t support operator overloading. The best I can suggest is a class method for making new quota objects from several others. Here’s a quick example of what I mean: // define an example “class” var NumClass = function(value){ this.value = value; } NumClass.prototype.toInteger … Read more
Just telling you about one other possibility: I like using friend definitions for that: namespace Math { class Matrix { public: […] friend std::ostream& operator<< (std::ostream& stream, const Matrix& matrix) { […] } }; } The function will be automatically targeted into the surrounding namespace Math (even though its definition appears within the scope of … Read more
Strictly speaking, the result of a copy assignment operator doesn’t need to return a reference, though to mimic the default behavior the C++ compiler uses, it should return a non-const reference to the object that is assigned to (an implicitly generated copy assignment operator will return a non-const reference – C++03: 12.8/10). I’ve seen a … Read more
std::endl is a function and std::cout utilizes it by implementing operator<< to take a function pointer with the same signature as std::endl. In there, it calls the function, and forwards the return value. Here is a code example: #include <iostream> struct MyStream { template <typename T> MyStream& operator<<(const T& x) { std::cout << x; return … Read more
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
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
Part I This C++ FAQ entry explained why one might want to overload new and delete operators for one’s own class. This present FAQ tries to explain how one does so in a standard-conforming way. Implementing a custom new operator The C++ standard (§18.4.1.1) defines operator new as: void* operator new (std::size_t size) throw (std::bad_alloc); … Read more
There are a lot of posts complaining about operator overloading. I felt I had to clarify the “operator overloading” concepts, offering an alternative viewpoint on this concept. Code obfuscating? This argument is a fallacy. Obfuscating is possible in all languages… It is as easy to obfuscate code in C or Java through functions/methods as it … Read more