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Retrieve only the queried element in an object array in MongoDB collection
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db.test.find({"shapes.color": "red"}, {_id: 0, 'shapes.$': 1});
MongoDB 3.2 Update
Starting with the 3.2 release, you can use the new $filter aggregation operator to filter an array during projection, which has the benefit of including all matches, instead of just the first one.
db.test.aggrega...
Is std::vector so much slower than plain arrays?
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Using the following:
g++ -O3 Time.cpp -I <MyBoost>
./a.out
UseArray completed in 2.196 seconds
UseVector completed in 4.412 seconds
UseVectorPushBack completed in 8.017 seconds
The whole thing completed in 14.626 seconds
So array is...
Difference between “git checkout ” and “git checkout -- ”
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edited Sep 8 '16 at 13:47
answered Jul 3 '11 at 4:51
z...
Forced naming of parameters in Python
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223
In Python 3 - Yes, you can specify * in the argument list.
From docs:
Parameters after “*...
Design for Facebook authentication in an iOS app that also accesses a secured web service
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n00bProgrammer
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answered Jan 7 '11 at 13:40
Dan RayDan Ray
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reference assignment is atomic so why is Interlocked.Exchange(ref Object, Object) needed?
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answered Feb 3 '10 at 16:20
Eric LippertEric Lippert
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Set width of a “Position: fixed” div relative to parent div
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answered May 3 '11 at 19:02
jeroenjeroen
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Set value for particular cell in pandas DataFrame using index
...y df.
In [18]: %timeit df.set_value('C', 'x', 10)
100000 loops, best of 3: 2.9 µs per loop
In [20]: %timeit df['x']['C'] = 10
100000 loops, best of 3: 6.31 µs per loop
In [81]: %timeit df.at['C', 'x'] = 10
100000 loops, best of 3: 9.2 µs per loop
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