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Cannot create an NSPersistentStoreCoordinator with a nil model
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This specific issue is caused by creating an extra model version and then attempting to delete it manually while Xcode is open. This causes some kind of corruption. You should not be passing in specific model versions in the momd directory.
– Mike ...
What are the differences between numpy arrays and matrices? Which one should I use?
... here. Instead of performing fewer checks, using matrix*matrix requires an extra function call. So the advantage of using matrix is purely syntactic, not better performance.
– unutbu
Sep 18 '17 at 20:44
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Use of alloc init instead of new
...selected ones are:
new doesn't support custom initializers (like initWithString)
alloc-init is more explicit than new
General opinion seems to be that you should use whatever you're comfortable with.
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How to pass optional arguments to a method in C++?
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Can you pls provide some example related to string ?
– Swapnil Gupta
Sep 24 '10 at 4:20
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Create a .txt file if doesn't exist, and if it does append a new line
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string path = @"E:\AppServ\Example.txt";
File.AppendAllLines(path, new [] { "The very first line!" });
See also File.AppendAllText(). AppendAllLines will add a newline to each line without having to put it there yourself.
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How are Python's Built In Dictionaries Implemented?
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For a 64 bit machine, this could save up to 16 bytes per key per extra dictionary.
Shared Keys for Custom Objects & Alternatives
These shared-key dicts are intended to be used for custom objects' __dict__. To get this behavior, I believe you need to finish populating your __dict__ be...
Is “double hashing” a password less secure than just hashing it once?
...len($input); $i++) {
$result += ord($input[$i]);
}
return (string) ($result % 256);
}
Now it should be pretty obvious what this hash function does. It sums together the ASCII values of each character of input, and then takes the modulo of that result with 256.
So let's test it out:
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How to determine if a list of polygon points are in clockwise order?
...worked perfectly for my use. Note that if you can plan ahead and spare and extra two vectors in your array, you can get rid of the comparison (or %) by adding the first vector at the tail of the array. That way you simply loop over all the elements, except the last one (length-2 instead of length-1)...
How to implement classic sorting algorithms in modern C++?
... cmp = Compare{});
In C++11, one can define a reusable template alias to extract an iterator's value type which adds minor clutter to the sort algorithms' signatures:
template<class It>
using value_type_t = typename std::iterator_traits<It>::value_type;
template<class It, class Co...
Setting DIV width and height in JavaScript
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The onclick attribute of a button takes a string of JavaScript, not an href like you provided. Just remove the "javascript:" part.
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