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val-mutable versus var-immutable in Scala
Are there any guidelines in Scala on when to use val with a mutable collection versus using var with an immutable collection? Or should you really aim for val with an immutable collection?
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How does RegexOptions.Compiled work?
...xpression as one to be compiled? How does this compare/is different from a cached regular expression?
5 Answers
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When do I use a dot, arrow, or double colon to refer to members of a class in C++?
...only used if b is a member of the class (or namespace) a. That is, in this case a will always be the name of a class (or namespace).
a.b is only used if b is a member of the object (or reference to an object) a. So for a.b, a will always be an actual object (or a reference to an object) of a class....
stringstream, string, and char* conversion confusion
My question can be boiled down to, where does the string returned from stringstream.str().c_str() live in memory, and why can't it be assigned to a const char* ?
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Exporting functions from a DLL with dllexport
...++ DLLs rely on name-mangling for all the C++isms (namespaces etc...). You can compile your code as C by going into your project settings under C/C++->Advanced, there is an option "Compile As" which corresponds to the compiler switches /TP and /TC.
If you still want to use C++ to write the intern...
Generating an MD5 checksum of a file
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You can use hashlib.md5()
Note that sometimes you won't be able to fit the whole file in memory. In that case, you'll have to read chunks of 4096 bytes sequentially and feed them to the md5 method:
import hashlib
def md5(fname)...
what exactly is device pixel ratio?
this is mentioned every article about mobile web, but nowhere I can found an explanation of what exactly does this attribute measure.
Can anyone please elaborate what does queries like this check?
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What is the meaning of the term arena in relation to memory?
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An arena is just a large, contiguous piece of memory that you allocate once and then use to manage memory manually by handing out parts of that memory. For example:
char * arena = malloc(HUGE_NUMBER);
unsigned int current = 0;
void * my_malloc(size_t n) { current += n; return arena + cur...
How to “warm-up” Entity Framework? When does it get “cold”?
...pproach to have high availability on my Entity Framework at anytime?
You can go for a mix of pregenerated views and static compiled queries.
Static CompiledQuerys are good because they're quick and easy to write and help increase performance. However with EF5 it isn't necessary to compile all you...
Why do == comparisons with Integer.valueOf(String) give different results for 127 and 128?
...e here.
valueOf is returning an Integer object, which may have its values cached between -128 and 127. This is why the first value returns true - it's cached - and the second value returns false - 128 isn't a cached value, so you're getting two separate Integer instances.
It is important to note ...