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Create singleton using GCD's dispatch_once in Objective-C
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difference between use and require
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not having to reconcile collisions is a good point, and more generally there's a programming style which says "namespaces are a honking great idea, we should have more of them" (from "The Zen of Python") -- so e.g. that style recommends not using "using namespace foo;" in C++, so ...
getting exception “IllegalStateException: Can not perform this action after onSaveInstanceState”
...ything works great. I hope this will save you some time.
EDIT: after some more research, this is a known bug in the support package.
If you need to save the instance, and add something to your outState Bundle you can use the following :
@Override
protected void onSaveInstanceState(Bundle outStat...
Is the pImpl idiom really used in practice?
...verhead (the resulting code on the client side will be the same).
What is more, with the standard header/implementation separation XClient1.cpp needs to be recompiled even when a private method X::foo() was added to X and X.h changed, even though XClient1.cpp can't possibly call this method for enc...
Measuring execution time of a function in C++
...ing for a function. This is because the CPU of your machine can be less or more used by other processes running on your computer, just as your mind can be more or less concentrated when you solve a math exercise. In the human mind, we can remember the solution of a math problem, but for a computer t...
How do SQL EXISTS statements work?
...ment for EXISTS, because there will be duplicate parent records if there's more than one child record associated to the parent.
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What is the JavaScript version of sleep()?
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Use ffmpeg to add text subtitles [closed]
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PHP check whether property exists in object or class
...t have a middle name';
To show how this would look in an if statement for more clarity on how this is working.
if($person->middleName ?? false) {
echo $person->middleName;
} else {
echo 'Person does not have a middle name';
}
Explanation
The traditional PHP way to check for someth...
What are the most-used vim commands/keypresses?
...ly use regularly:
References
vim documentation online
advanced vim tips
more useful tips and graphical cheat sheet
General
Nearly all commands can be preceded by a number for a repeat count. eg. 5dd delete 5 lines
<Esc> gets you out of any mode and back to command mode
Commands preceded...