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Get the current first responder without using a private API
...that my app cannot be accepted because I'm using a non-public API; specifically, it says,
28 Answers
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sizeof single struct member in C
... char text[member_size(Parent, text)];
int used;
} Child;
I'm actually a bit surprised that sizeof((type *)0)->member) is even allowed as a constant expression. Cool stuff.
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impr...
Greenlet Vs. Threads
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Greenlets provide concurrency but not parallelism. Concurrency is when code can run independently of other code. Parallelism is the execution of concurrent code simultaneously. Parallelism is particularly useful when there's a lot of work to be done in userspace, an...
_DEBUG vs NDEBUG
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+1. NDEBUG in particular is allowed to be #undef'd and #define'd within a single TU (and reincluding <assert.h> changes the assert macro accordingly). Because this is different than expected/desired, it's common to use another macro to control a ...
Why use sprintf function in PHP?
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sprintf has all the formatting capabilities of the original printf which means you can do much more than just inserting variable values in strings.
For instance, specify number format (hex, decimal, octal), number of decimals, padding a...
Retrieve only the queried element in an object array in MongoDB collection
...r to filter an array during projection, which has the benefit of including all matches, instead of just the first one.
db.test.aggregate([
// Get just the docs that contain a shapes element where color is 'red'
{$match: {'shapes.color': 'red'}},
{$project: {
shapes: {$filter: {
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How to fix a locale setting warning from Perl?
...cale failed.
perl: warning: Please check that your locale settings:
LC_ALL = (unset),
LANG = "en_US.UTF-8"
are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
My guess is you used ssh to connect to this older host from a newer desktop ma...
Two submit buttons in one form
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Normally, all inputs in the form are sent with the form. Since a button's value is submitted only if clicked, you'd have to search the form values for these pre-defined names. I think the other answer (stackoverflow.com/a/21778...
What is the difference between Θ(n) and O(n)?
...e of the algorithm as n gets larger is at most proportional to g(n).
Normally, even when people talk about O(g(n)) they actually mean Θ(g(n)) but technically, there is a difference.
More technically:
O(n) represents upper bound. Θ(n) means tight bound.
Ω(n) represents lower bound.
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Python extract pattern matches
...h a standard python REPL, the last result is stored in a special variable called _. It isn't valid outside anywhere else.
– UltraInstinct
Mar 13 '19 at 2:25
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