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Does free(ptr) where ptr is NULL corrupt memory?
... (ptr)
free(ptr);
This is because some C runtimes (I for sure remember it was the case on PalmOS) would crash when freeing a NULL pointer.
But nowadays, I believe it's safe to assume free(NULL) is a nop as per instructed by the standard.
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Which kind of pointer do I use when?
...ded. I understand that C++11 now provides some of the types boost came up with, but not all of them.
4 Answers
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Where does the @Transactional annotation belong?
...place the @Transactional in the DAO classes and/or their methods or is it better to annotate the Service classes which are calling using the DAO objects? Or does it make sense to annotate both "layers"?
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Exporting a function in shell
... is exported function available only for child calls? How to apply it to current bash session? like to .bashrc writing, but only for current bash instance...
– vp_arth
May 3 '14 at 15:37
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NameValueCollection vs Dictionary [duplicate]
...cannot.
Personally if you don't have duplicate keys, then I would stick with the Dictionary. It's more modern, uses IEnumerable<> which makes it easy to mingle with Linq queries. You can even create a Dictionary using the Linq ToDictionary() method.
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Facebook Open Graph not clearing cache
I'm having troubles with my meta tags with Open Graph. It seems as though Facebook is caching old values of my meta tags. Old values for Attributes og:title and og:url are still used, even though I have changed them already.
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Apply formula to the entire column
I'm trying to recode all the zip code from Column A into Column B with the formula:
10 Answers
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What does the line “#!/bin/sh” mean in a UNIX shell script?
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It's called a shebang, and tells the parent shell which interpreter should be used to execute the script.
e.g.
#!/usr/bin/perl <--perl script'
#!/usr/bin/php <-- php script
#!/bin/false <--- do-nothing script, be...
When should I use Kruskal as opposed to Prim (and vice versa)?
I was wondering when one should use Prim's algorithm and when Kruskal's to find the minimum spanning tree? They both have easy logics, same worst cases, and only difference is implementation which might involve a bit different data structures. So what is the deciding factor?
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What's the main difference between int.Parse() and Convert.ToInt32
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If you've got a string, and you expect it to always be an integer (say, if some web service is handing you an integer in string format), you'd use Int32.Parse().
If you're collecting input from a user, you'd generally use Int32.TryParse(), since it allows you mor...