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How do I declare an array of weak references in Swift?

...T] { return objects.flatMap { $0.object } } func contains(_ object: T) -> Bool { return self.objects.contains(WeakObject(object: object)) } func addObject(_ object: T) { self.objects.formUnion([WeakObject(object: object)]) } func addObjects(_ obj...
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Set value to NULL in MySQL

... can be inserted/updated without quotes: INSERT INTO user (name, something_optional) VALUES ("Joe", NULL); UPDATE user SET something_optional = NULL; share | improve this answer | ...
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What's an appropriate HTTP status code to return by a REST API service for a validation failure?

...inced that this is an appropriate code for a validation failure, what do y'all recommend? 7 Answers ...
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difference between primary key and unique key

...d on multiple columns, e.g. Primary key (CustomerID, ProductID). This is called composite primary key. This is to clarify the first point, as it might be take as it is (read one key => one column ) by new comer to sql : ) – ken Apr 10 '14 at 13:53 ...
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How can I redirect HTTP requests made from an iPad?

... Just for the record I'd say that is pretty easy to install squid using macports "sudo port install squid" – MiQUEL May 4 '13 at 18:18 ...
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Convert string with commas to array

... Convert all type of strings var array = (new Function("return [" + str+ "];")()); var string = "0,1"; var objectstring = '{Name:"Tshirt", CatGroupName:"Clothes", Gender:"male-female"}, {Name:"Dress", CatGroupName:"Clothes", Gend...
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How to convert JSON to XML or XML to JSON?

...t in JSON format. Your answer was probably downvoted because it didn't actually answer the question. The OP wasn't asking if he should do the conversion, but rather if he could do it using tools already at his disposal. – David Brown Aug 1 '12 at 3:08 ...
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How to remove all debug logging calls before building the release version of an Android app?

According to Google, I must " deactivate any calls to Log methods in the source code " before publishing my Android app to Google Play. Extract from section 3 of the publication checklist : ...
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Scala @ operator

...n itself? That would be accomplished with this: o match { case x @ Some(_) => println(x) case None => } Note that @ can be used at any level, not just at the top level of the matching. share | ...
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How to sort with a lambda?

...nclude <iostream> #include <sstream> struct Foo { Foo() : _i(0) {}; int _i; friend std::ostream& operator<<(std::ostream& os, const Foo& f) { os << f._i; return os; }; }; typedef std::vector<Foo> VectorT; std::string ...