Use std::addressof. You can think of it as doing the following behind the scenes: Reinterpret the object as a reference-to-char Take the address of that (won’t call the overload) Cast the pointer back to a pointer of your type. Existing implementations (including Boost.Addressof) do exactly that, just taking additional care of const and volatile qualification.
This is not currently possible, because extension methods must be in static classes, and static classes can’t have operator overloads. But the feature is being discussed for some future release of C#. Mads talked a bit more about implementing it in this video from 2017. On why it isn’t currently implemented, Mads Torgersen, C# Language … Read more
No, Java doesn’t support user-defined operator overloading. The only aspect of Java which comes close to “custom” operator overloading is the handling of + for strings, which either results in compile-time concatenation of constants or execution-time concatenation using StringBuilder/StringBuffer. You can’t define your own operators which act in the same way though. For a Java-like … Read more
MyClass.__contains__(self, item)
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
you can find how to do it here. In short it is: public object this[int i] { get { return InnerList[i]; } set { InnerList[i] = value; } } If you only need a getter the syntax in answer below can be used as well (starting from C# 6).
You would not want the language to automatically rewrite a != b as !(a == b) when a == b returns something other than a bool. And there are a few reasons why you might make it do that. You may have expression builder objects, where a == b doesn’t and isn’t intended to perform … Read more
You need to use the __getitem__ method. class MyClass: def __getitem__(self, key): return key * 2 myobj = MyClass() myobj[3] #Output: 6 And if you’re going to be setting values you’ll need to implement the __setitem__ method too, otherwise this will happen: >>> myobj[5] = 1 Traceback (most recent call last): File “<stdin>”, line 1, … Read more
Yes, the code is standard conforming. The + triggers a conversion to a plain old function pointer for the lambda. What happens is this: The compiler sees the first lambda ([]{}) and generates a closure object according to §5.1.2. As the lambda is a non-capturing lambda, the following applies: 5.1.2 Lambda expressions [expr.prim.lambda] 6 The … Read more
public int this[int key] { get => GetValue(key); set => SetValue(key, value); }