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How do I show the value of a #define at compile-time?
...ring. When there is more than one component to the argument then they must all be strings so that string concatenation can be applied. The preprocessor can never assume that an unquoted string should be treated as if it were quoted. If it did then:
#define ABC 123
int n = ABC;
would not compile.
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What is the volatile keyword useful for?
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volatile has semantics for memory visibility. Basically, the value of a volatile field becomes visible to all readers (other threads in particular) after a write operation completes on it. Without volatile, readers could see some non-updated value.
To answer your question: Y...
How to read/process command line arguments?
I am originally a C programmer. I have seen numerous tricks and "hacks" to read many different arguments.
17 Answers
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Backbone.js: get current route
... hashchange events or pushState, match the appropriate route, and trigger callbacks. You shouldn't ever have to create one of these yourself — you should use the reference to Backbone.history that will be created for you automatically if you make use of Routers with routes.
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If you need the...
How do I get the object if it exists, or None if it does not exist?
... python is to wrap it in a try catch:
try:
go = SomeModel.objects.get(foo='bar')
except SomeModel.DoesNotExist:
go = None
What I did do, is to subclass models.Manager, create a safe_get like the code above and use that manager for my models. That way you can write: SomeModel.objects.safe_...
How to define an alias in fish shell?
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@kyb, nope, fish is smarter than bash like that. Actually, ALL variables in fish are arrays. Go to Shell variables and scroll down to the Arrays subsection
– glenn jackman
Feb 28 '19 at 21:08
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SELECT DISTINCT on one column
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this is really useful case in any various duplication thank you
– ASLIM
Jan 13 at 8:08
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How do I get a class instance of generic type T?
... of Foo , I want to get the class instance of type T , but I just can't call T.class .
21 Answers
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How to sort git tags by version string order of form rc-X.Y.Z.W?
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you can use homebrew or macports to install the gnu version of sort. brew install gsort then you can modify the line above to git tag -l | gsort -V and it should work for you.
– Goran
Feb 24 '14 at 13:16
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How to use sed to replace only the first occurrence in a file?
...lude directive before any existing #includes. For this sort of task, I normally use a small bash script with sed to re-write the file.
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