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Using “super” in C++
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D & E is indeed a good book. But it seems like I'll need to re-read it - I don't remember either story.
– Michael Burr
Oct 8 '08 at 4:37
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How does the MapReduce sort algorithm work?
... 1 sampled keys that define the key range for each reduce. In particular, all keys such that sample[i − 1] <= key < sample[i] are sent to reduce i. This guarantees that the output of reduce i are all less than the output of reduce i+1."
So their trick is in the way they determine the keys ...
Assigning a variable NaN in python without numpy
...aking) be said to be equal to one another -- see What is the rationale for all comparisons returning false for IEEE754 NaN values? for more details and information.
Instead, use math.isnan(...) if you need to determine if a value is NaN or not.
Furthermore, the exact semantics of the == operation...
Multiline bash commands in makefile
...colon:
foo:
for i in `find`; \
do \
all="$$all $$i"; \
done; \
gcc $$all
But if you just want to take the whole list returned by the find invocation and pass it to gcc, you actually don't necessarily need a multiline command:
foo:
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Is std::unique_ptr required to know the full definition of T?
...ak memory as ~A() won't be called.
Using auto_ptr<A> in the above example doesn't help. You still get the same undefined behavior as if you had used a raw pointer.
Nevertheless, using incomplete classes in certain places is very useful! This is where shared_ptr and unique_ptr help. Use of on...
Removing viewcontrollers from navigation stack
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Swift 3 & 4/5
self.navigationController!.viewControllers.removeAll()
self.navigationController?.viewControllers.remove(at: "insert here a number")
Swift 2.1
remove all:
self.navigationController!.viewControllers.removeAll...
Regular expression \p{L} and \p{N}
... by .NET, Perl, Java, PCRE, XML, XPath, JGSoft, Ruby (1.9 and higher) and PHP (since 5.1.0)
At any rate, that's a very strange regex. You should not be using alternation when a character class would suffice:
[\p{L}\p{N}_.-]*
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How to import an excel file in to a MySQL database
...s. Here is a recent example I used to import a csv file named test.csv.
phpMyAdmin: Select your database first, then select the Import tab. phpMyAdmin will automatically create your table and size your VARCHAR fields, but it won't optimize the field types. phpMyAdmin has trouble importing large...
Extract digits from a string in Java
...ava String object. I need to extract only digits from it. I'll give an example:
14 Answers
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What are the Dangers of Method Swizzling in Objective-C?
...informed decisions about whether or not to use it. Singletons are a good example of something that's pretty controversial, and for good reason — they're really hard to implement properly. Many people still choose to use singletons, though. The same can be said about swizzling. You should form your...