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Is std::vector so much slower than plain arrays?
...are not only allocating the memory but also running through the vector and calling the constructor on each member.
Re-Arranging the code slightly so that the vector only initializes each object once:
std::vector<Pixel> pixels(dimensions * dimensions, Pixel(255,0,0));
Now doing the same t...
How do I convert an existing callback API to promises?
I want to work with promises but I have a callback API in a format like:
20 Answers
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What is the meaning of “non temporal” memory accesses in x86
...e and a mask indicates what parts of the line are up-to-date. This webpage calls it "no stall on store": ptlsim.org/Documentation/html/node30.html . I couldn't find more precise references, I only heard about this from guys whose job is to implement processor simulators.
– Pasc...
How can you automatically remove trailing whitespace in vim
...use vim; they don't because they'd have to install it). I have a program I call stb to Strip Trailing Blanks and I use that as a filter; works in vi too. This is better.
– Jonathan Leffler
Jan 15 '09 at 14:06
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If strings are immutable in .NET, then why does Substring take O(n) time?
...ct tiny substrings from tiny strings, so how the complexity grows asymptotically is completely irrelevant.
The long answer is:
An immutable data structure built such that operations on an instance permit re-use of the memory of the original with only a small amount (typically O(1) or O(lg n)) of c...
Is it possible to refresh a single UITableViewCell in a UITableView?
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The OP isn't animating anything, so there's no need to call the begin/endupdates
– kubi
Jul 15 '13 at 17:38
2
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Show the progress of a Python multiprocessing pool imap_unordered call?
...sfully doing a multiprocessing Pool set of tasks with a imap_unordered() call:
9 Answers
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Easily measure elapsed time
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You can abstract the time measuring mechanism and have each callable's run time measured with minimal extra code, just by being called through a timer structure. Plus, at compile time you can parametrize the timing type (milliseconds, nanoseconds etc).
Thanks to the review by Loki A...
How can I rollback a github repository to a specific commit?
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git reset --hard <old-commit-id>
git push -f <remote-name> <branch-name>
Note: As written in comments below, Using this is dangerous in a collaborative environment: you're rewriting history
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How do I catch a PHP fatal (`E_ERROR`) error?
...most PHP errors, but it doesn't work for fatal ( E_ERROR ) errors, such as calling a function that doesn't exist. Is there another way to catch these errors?
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