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Proper use of beginBackgroundTaskWithExpirationHandler

...l need to wrap it in a background task. It's also very important that you call endBackgroundTask when you're finished - otherwise the app will be killed after its allotted time has expired. Mine tend look something like this: - (void) doUpdate { dispatch_async(dispatch_get_global_queue(DISPAT...
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How to convert a String to its equivalent LINQ Expression Tree?

...nking as a Where clause. If necessary, put it inside a list/array just to call .Where(string) on it! i.e. var people = new List<Person> { person }; int match = people.Where(filter).Any(); If not, writing a parser (using Expression under the hood) isn't hugely taxing - I wrote one similar (a...
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Android NDK C++ JNI (no implementation found for native…)

...g the function prototype name wrong, another is failing to load the .so at all. Are you sure that System.loadLibrary() is being called before the method is used? If you don't have a JNI_OnLoad function defined, you may want to create one and have it spit out a log message just to verify that the l...
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boost::flat_map and its performance compared to map and unordered_map

...e, because your cache will not be warm, and your operation will likely be called just once. Therefore you need to benchmark using RDTSC, and time stuff calling them once only. Intel has made a paper describing how to use RDTSC (using a cpuid instruction to flush the pipeline, and calling it at least...
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When should I use GET or POST method? What's the difference between them?

... What I meant was that contents of $_POST is not magically hidden from malicious users. There are obviously security aspects to all thing programming. – troelskn Feb 2 '09 at 22:34 ...
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Migration: Cannot add foreign key constraint

...signed(); $table->string('priority_name'); $table->smallInteger('rank'); $table->text('class'); $table->timestamps('timecreated'); }); Schema::table('priorities', function($table) { $table->foreign('user_id')->references('id')->on('...
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Private and Protected Members : C++

... Public members of a class A are accessible for all and everyone. Protected members of a class A are not accessible outside of A's code, but is accessible from the code of any class derived from A. Private members of a class A are not accessible outside of A's code, or f...
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Dashed line border around UIView

...t@2x.png and test@3x.png with size of 240x240 and 360x360 which is used in all the apple device automatically with it's related name. (i.e. test.png is use in iPhone 4, test@2x will useful for iPhone 4s, 5, 5s, 6, 6s and twst@3x will useful for iPhone 6 plus, 6s plus. – Paras J...
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Why are Subjects not recommended in .NET Reactive Extensions?

... Ok, If we ignore my dogmatic ways and ignore "subjects are good/bad" all together. Let us look at the problem space. I bet you either have 1 of 2 styles of system you need to ingrate to. The system raises an event or a call back when a message arrives You need to poll the system to see if t...
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How to get the Power of some Integer in Swift language?

... I really like this solution, but with Swift 3 it does not work. Any idea how to make it work? – Vanya Sep 19 '16 at 18:51 ...