typecast-operator

Before I start, I have already read the Swift documentation. I am still trying to comprehend what AnyObject actually is. Is it a base class for all objects/classes in Swift, as NSObject is in Objective C? If I create an array of type [AnyObject] and populate it with Movie class instances, that would mean that AnyObject is a base class of the Movie class right? let someObjects: [AnyObject] = [ Movie(name: "2001: A Space Odyssey", director: "Stanley Kubrick"), Movie(name: "Moon", director: "Duncan Jones"), Movie(name: "Alien", director: "Ridley Scott") ] This should be true or else you wouldn't

As we know, the type cast is called assertion type in TypeScript. And the following code section: // the variable will change to true at onetime let isPlay: boolean = false; let actions: string[] = ['stop', 'play']; let action: string = actions[<number> isPlay]; On compiling, it go wrong Error:(56, 35) TS2352: Neither type 'boolean' nor type 'number' is assignable to the other. Then I try to use the any type: let action: string = actions[<number> <any> isPlay]; Also go wrong. How can I rewrite those code. You can't just cast it, the problem is at runtime not only at compile time. You have a

The question rose in context of this answer . Consider an example: struct foo { int value; operator int&(){ return value; } operator int(){ return value; } }; int main () { int &a(foo{}); // #1 //int &b{foo{}}; // #2 -- ambiguity int &c = foo{}; // #3 //int &d = {foo{}}; // #4-- ambiguity int &d { a }; // #5 int &e = { a }; // #6 (void)a; (void)c; (void)d; (void)e; } I don't understand why does #2 and #4 cause ambiguity while #1 and #3 does not. So the question is - why does direct list initialization causes ambiguity for implicit cast to reference if cast operators to the type and reference

struct A {}; struct B { B (A* pA) {} B& operator = (A* pA) { return *this; } }; template<typename T> struct Wrap { T *x; operator T* () { return x; } }; int main () { Wrap<A> a; B oB = a; // error: conversion from ‘Wrap<A>’ to non-scalar type ‘B’ requested oB = a; // ok } When oB is constructed then Why B::B(A*) is NOT invoked for Wrap<T>::operator T () ? [Note: B::operator = (A*) is invoked for Wrap<T>::operator T () in the next statement] The problem is that the number of user-defined conversions that are invoked implicitly is limited (to 1) by the Standard. B ob = a; implies two user

Is it possible to write custom conversion (casting) operator in swift ? Especially I'm looking for enums conversion, ex: enum MyEnum : Int { case Case1 = 0 case Case2 func __conversion() -> String { // doesn't work since Swift 1.0 switch self { case Case1: return "Case 1" case Case2: return "Case 2" } } } let enumStr: String = MyEnum.Case1 Of course, I can convert to String with explicit method, but I would like to have implicit mechanism. dfri Disclaimer/TL;DR! This answer pertains to the technical question as to whether we can possibly implement implicit bridging mechanisms between different

This question already has an answer here: Double colon (::) notation in SQL 4 answers I have seen :: in variety of places involving postgres code I have seen on the net. For example: SELECT '{apple,cherry apple, avocado}'::text[]; It seems to be some sort of cast. What exactly is :: in postgres and when should it be used? I tried a bit of googling and searched the Postgres docs for :: but got no good results. I tried following searches in Google: postgres double colon postgres :: :: I tried the following searches in the postgres docs search button double colon double colon cast :: This was

I have this code type TXSample = (xsType1, xsType2, xsType3, xsType4, xsType5, xsType6, xsType6, xsTyp7, xsType8); // up to FXSample30; .. private FXSample = Set of TXSample; .. published property Sample: TXSample read FXSample write FXSample; .. //if Sample has a value of Sample := [xsType2, xsType4, xsType5, xsType6, xsTyp7]; how can i save/load the property of Sample? i would like to save it in the database. is it possible? NGLN Provided your set will never exceed 32 possibilities ( Ord(High(TXSample)) <= 31 ), then it is perfectly fine to typecast the set into an Integer and back: type