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Why can't I use switch statement on a String?
...t compile time. At runtime, while the O(1) performance of tableswitch generally appears better than the O(log(n)) performance of lookupswitch, it requires some analysis to determine whether the table is dense enough to justify the space–time tradeoff. Bill Venners wrote a great article that covers...
Should I pass an std::function by const-reference?
...rmance, pass by value if you are storing it.
Suppose you have a function called "run this in the UI thread".
std::future<void> run_in_ui_thread( std::function<void()> )
which runs some code in the "ui" thread, then signals the future when done. (Useful in UI frameworks where the UI ...
What makes Scala's operator overloading “good”, but C++'s “bad”?
...t to be repeated in newer languages. Certainly, it was one feature specifically dropped when designing Java.
14 Answers
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How to pad zeroes to a string?
...ited in the parens; since only one thing is being printed, it works identically now on Py2 and Py3.
– ShadowRanger
Jan 25 '19 at 2:19
2
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GitHub relative link in Markdown file
...entation files, whether you view the documentation on GitHub itself, or locally, using a different markup renderer.
You want examples of link definitions and how they work? Here's some Markdown for you.
Instead of an absolute link:
[a link](https://github.com/user/repo/blob/branch/other_file...
dyld: Library not loaded: @rpath/libswift_stdlib_core.dylib
... went away. Makes sense, but given how much other stuff Xcode 6.0 automagically configures for you, it's a shame this essential option was overlooked.
– hsoi
Sep 16 '14 at 11:10
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How to get key names from JSON using jq
...fy -r then you get a quoted string, which looks fine on-screen, but you usually don't want the quotes embedded in the string.
– MarkHu
Apr 26 '18 at 2:49
4
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Compare double to zero using epsilon
...0 00000000 00000000 00000000 00000000 00000000 00000000 × 2^0 = 1
The smallest representable number greater than 1:
1.0000 00000000 00000000 00000000 00000000 00000000 00000001 × 2^0 = 1 + 2^-52
Therefore:
epsilon = (1 + 2^-52) - 1 = 2^-52
Are there any numbers between 0 and epsilon? Plent...
What are Unwind segues for and how do you use them?
...
In a Nutshell
An unwind segue (sometimes called exit segue) can be used to navigate back through push, modal or popover segues (as if you popped the navigation item from the navigation bar, closed the popover or dismissed the modally presented view controller). On to...
Converting a column within pandas dataframe from int to string
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I really don't understand why, but mtrx['X.3'].apply(str) does not work for me either :( dtype still shows int64. The dataframe for 23177 row and X.3 column got only numbers. In [21]: mtrx['X.3'].dtype Out[21]: dtype('i...