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How do you implement a class in C? [closed]
...s the proper class, i.e. RectangleClass *. This means you often have to do casts, but they provide handy macros do help with that, so you can always cast BASECLASS *p to SUBCLASS * using just SUBCLASS(p).
– unwind
Sep 10 '09 at 8:03
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Image fingerprint to compare similarity of many images
...produce a normative mapping of the image data - store this with each image and then compare just the fingerprints. This is a complex algorithm and not for the faint of heart.
a few simple solutions are possible:
Create a luminosity histogram for the image as a fingerprint
Create scaled down versi...
What is a good Hash Function?
What is a good Hash function? I saw a lot of hash function and applications in my data structures courses in college, but I mostly got that it's pretty hard to make a good hash function. As a rule of thumb to avoid collisions my professor said that:
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PHP random string generator
I'm trying to create a randomized string in PHP, and I get absolutely no output with this:
59 Answers
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How to convert a string to an integer in JavaScript?
...ly coercing the string into a number. I prefer to do this explicitly,
var cast = Number("97");
This has different behavior to the parse methods (although it still ignores whitespace). It's more strict: if it doesn't understand the whole of the string than it returns NaN, so you can't use it for s...
Why is unsigned integer overflow defined behavior but signed integer overflow isn't?
...and Y, there will exist some other value Z such that X+Z will, if properly cast, equal Y and Y-Z will, if properly cast, equal X). If unsigned values were merely storage-location types and not intermediate-expression types (e.g. if there were no unsigned equivalent of the largest integer type, and ...
Which UUID version to use?
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Version 1: This generates a unique ID based on a network card MAC address and a timer. These IDs are easy to predict (given one, I might be able to guess another one) and can be traced back to your network card. It's not recommended to create these.
Version 4: These are generated from random (or ps...
What is __stdcall?
... __stdcall Scene::ExecuteCommand(void* command)
{
return system(static_cast<char*>(command));
}
UIDevice uniqueIdentifier deprecated - What to do now?
...ght that the UIDevice uniqueIdentifier property is deprecated in iOS 5 and unavailable in iOS 7 and above. No alternative method or property appears to be available or forthcoming.
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What should I do if two libraries provide a function with the same name generating a conflict?
...ULE lib = LoadLibrary("foo.dll");
void *p = GetProcAddress(lib, "bar");
// cast p to the approriate function pointer type (fp) and call it
(*fp)(arg1, arg2...);
FreeLibrary(lib);
would get the address of a function named bar in foo.dll and call it.
I know Unix systems support similar functionalit...