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Shall we always use [unowned self] inside closure in Swift

... in order to make sure that it is still around by the time the closure is called. Example: Making an asynchronous network request If you are making an asynchronous network request you do want the closure to retain self for when the request finishes. That object may have otherwise been deallocated ...
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psql: FATAL: database “” does not exist

... it in the past on other machines but it's giving me some trouble when installing on my macbook. I've installed the application and I ran: ...
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Reading in a JSON File Using Swift

I'm really struggling with trying to read a JSON file into Swift so I can play around with it. I've spent the best part of 2 days re-searching and trying different methods but no luck as of yet so I have signed up to StackOverFlow to see if anyone can point me in the right direction..... ...
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Does Java SE 8 have Pairs or Tuples?

..., value[i]) , then filter based on the second value[i] element, and finally output just the indices. 9 Answers ...
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What is the difference between “def” and “val” to define a function

...ion every time (new instance of Function1). def even: Int => Boolean = _ % 2 == 0 even eq even //Boolean = false val even: Int => Boolean = _ % 2 == 0 even eq even //Boolean = true With def you can get new function on every call: val test: () => Int = { val r = util.Random.nextInt ...
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Ternary Operator Similar To ?:

...or that we just defined: object T { val condition = true import Bool._ // yay! val x = condition ? "yes" | "no" } Have fun ;) share | improve this answer | ...
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Use of def, val, and var in scala

...sed: scala> something = 5 * 6 <console>:8: error: value something_= is not a member of object $iw something = 5 * 6 ^ When the class is defined like: scala> class Person(val name: String, var age: Int) defined class Person and then instantiated with: scala> def pe...
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Linq Query keeps throwing “Unable to create a constant value of type System.Object…”, Why?

...tBindingSource.Position = accountBindingSource.IndexOf(_dataService.Db.Accounts.First(ac => ac.AccountName == name)); accountBindingSource_CurrentChanged(sender, e); } buggy code: private void onTopAccBtnClick(object sender, EventArgs e) { accountBin...
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How to express a One-To-Many relationship in Django

... sure there's a way to do this, so I'm not sure what I'm missing. I essentially have something like this: 8 Answers ...
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Why is SSE scalar sqrt(x) slower than rsqrt(x) * x?

...ill somewhat faster than sqrtss. edit: If speed is critical, and you're really calling this in a loop for many values, you should be using the vectorized versions of these instructions, rsqrtps or sqrtps, both of which process four floats per instruction. ...