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Scala: Nil vs List()
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scala> println (Nil == List())
true
scala> println (Nil eq List())
true
scala> println (Nil equals List())
true
scala> System.identityHashCode(Nil)
374527572
scala> System.identityHashCode(List())
374527572
Nil is mo...
Why don't C++ compilers define operator== and operator!=?
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The compiler wouldn't know whether you wanted a pointer comparison or a deep (internal) comparison.
It's safer to just not implement it and let the programmer do that themselves. Then they can make all the assumptions they like.
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How to add icon inside EditText view in Android ?
...in response to an event. To do this use the method setCompoundDrawablesWithIntrincisBounds(int, int, int, int):
EditText editText = findViewById(R.id.myEditText);
// Set drawables for left, top, right, and bottom - send 0 for nothing
editTxt.setCompoundDrawablesWithIntrinsicBounds(R.drawable.myDra...
How to overload std::swap()
... that's the only kind of definition that matters to generic code. Because int et. al. don't/can't have member functions, std::sort et. al. have to use a free function; they establish the protocol. Second, I don't know why you object to having two implementations, but most classes are doomed to bei...
What is the best way to programmatically detect porn images? [closed]
...r six-month-old, it's similarly likely to be detained.
It's only fair to point out amusing errors, like calling the Mona Lisa porn, if they're representative of the behaviour of the software. If the makers admit that their algorithmic image recogniser will drop the ball 15% of the time, then making ...
Differences between Perl and PHP [closed]
...rators. In Perl, if you use <, >, ==, !=, <=>, and so on, Perl converts both operands to numbers. If you want to convert as strings instead, you have to use lt, gt, eq, ne, cmp (the respective equivalents of the operators listed previously). Examples where this will really get you:
if (...
How to parse JSON in Scala using standard Scala classes?
...resents a Map of Strings to Any
case Some(map: Map[String, Any]) => println(map)
case None => println("Parsing failed")
case other => println("Unknown data structure: " + other)
}
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Java String array: is there a size of method?
..., .length (property-like, not a method):
String[] array = new String[10];
int size = array.length;
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Why start an ArrayList with an initial capacity?
... more efficient to specify the initial capacity. If you don't do this, the internal array will have to be repeatedly reallocated as the list grows.
The larger the final list, the more time you save by avoiding the reallocations.
That said, even without pre-allocation, inserting n elements at the b...
Best way to serialize an NSData into a hexadeximal string
I am looking for a nice-cocoa way to serialize an NSData object into a hexadecimal string. The idea is to serialize the deviceToken used for notification before sending it to my server.
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