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getting type T from IEnumerable

... Or even worse write a method with yield returns and try to call GetType on a variable created with this method. It will tell you that it is not event a generic type. So basically there is no universal way to get T given an instance variable of type IEnumerable<T> ...
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Unbalanced calls to begin/end appearance transitions for

...e not-suitable (like during initialization) procedure finishes, by doing: __weak MyViewController *weakSelf = self; dispatch_async(dispatch_get_main_queue(), ^{ [weakSelf presentViewController:vc animated:YES]; }); This is general for also pushViewController:animated:, etc. ...
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Setting UIButton image results in blue button in iOS 7

... In iOS7 there is new button type called UIButtonTypeSystem NS_ENUM_AVAILABLE_IOS(7_0), // standard system button Check your .xib file and change button type to Custom To do this programmatically, add this line to the viewDidLoad: [UIButton buttonWithType...
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Sending a message to nil in Objective-C

...I wonder what " sending a message to nil " means - let alone how it is actually useful. Taking an excerpt from the documentation: ...
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Swift: declare an empty dictionary

...ou have to be explicit, otherwise you will produce an unusable instance of __NSDictionaryI. Try adding an element to that emptyDict and it will fail at compile time. – Gabriele Petronella Jun 4 '14 at 13:34 ...
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What is the difference between HAVING and WHERE in SQL?

...nt(1) From Address Where State = 'MA' Group By City Gives you a table of all cities in MA and the number of addresses in each city. This code: select City, CNT=Count(1) From Address Where State = 'MA' Group By City Having Count(1)>5 Gives you a table of cities in MA with more than 5 address...
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How to calculate dp from pixels in android programmatically [duplicate]

I want to calculate dp from px programmatically. How to do it? I get resolution from: 4 Answers ...
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Automatically update version number

...ce the revision and build numbers with a coded date/timestamp, which is usually also a good way. For more info, see the Assembly Linker Documentation in the /v tag. As for automatically incrementing numbers, use the AssemblyInfo Task: AssemblyInfo Task This can be configured to automatically in...
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How to loop through an associative array and get the key? [duplicate]

... using PHP 5, you should avoid using foreach by reference values and since all foreaches use internal array pointer ( current($Array) ) nesting foreaches or using PHP array functions can do weird things. – Chaoix Jul 12 '19 at 15:13 ...
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How to avoid “Permission denied” when using pip with virtualenv

...ed Oct 19 '13 at 23:02 sebastian_oesebastian_oe 6,63822 gold badges1515 silver badges2020 bronze badges ...