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MongoDB SELECT COUNT GROUP BY
...ier way to do it using aggregate:
db.contest.aggregate([
{"$group" : {_id:"$province", count:{$sum:1}}}
])
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What 'additional configuration' is necessary to reference a .NET 2.0 mixed mode assembly in a .NET 4
...
In order to use a CLR 2.0 mixed mode assembly, you need to modify your App.Config file to include:
<?xml version="1.0"?><configuration> <startup useLegacyV2RuntimeActivationPolicy="true"> <supportedRunt...
How to shuffle a std::vector?
...#include <algorithm>
#include <random>
auto rng = std::default_random_engine {};
std::shuffle(std::begin(cards_), std::end(cards_), rng);
Live example on Coliru
Make sure to reuse the same instance of rng throughout multiple calls to std::shuffle if you intend to generate different p...
How can I expand the full path of the current file to pass to a command in Vim?
...ught me here, this should be the chosen answer.
– doc_id
Mar 2 '13 at 1:15
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Updating MySQL primary key
I have a table user_interactions with 4 columns:
3 Answers
3
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clang: how to list supported target architectures?
...e triples requires solving the Halting Problem. See, for example, llvm::ARM_MC::ParseARMTriple(...) which special-cases parsing the string "generic".
Ultimately, though, the "triple" is mostly a backwards-compatibility feature to make Clang a drop-in replacement for GCC, so you generally don't need...
clang error: unknown argument: '-mno-fused-madd' (python package installation failure)
...s/2.7/include/python2.7 -fno-strict-aliasing -fno-common -dynamic -arch x86_64 -arch i386 -g -Os -pipe -fno-common -fno-strict-aliasing -fwrapv -mno-fused-madd -DENABLE_DTRACE -DMACOSX -DNDEBUG -Wall -Wstrict-prototypes -Wshorten-64-to-32 -DNDEBUG -g -fwrapv -Os -Wall -Wstrict-prototypes -DENABLE_DT...
Twitter image encoding challenge [closed]
...um number of bits you can encode in a single utf8 character is 31 bits. In order to do this, I would use all characters that are in the U-04000000 – U-7FFFFFFF range. (1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx, there are 31 x's, therefore I could encode up to 31 bits).
31 bits times 14...
Does bit-shift depend on endianness?
... new value is stored back in memory, which is where the little endian byte order comes into effect again.
Update, thanks to @jww: On PowerPC the vector shifts and rotates are endian sensitive. You can have a value in a vector register and a shift will produce different results on little-endian and...
How do I search for an object by its ObjectId in the mongo console?
...est.find() // no criteria
{ "_id" : ObjectId("4ecc05e55dd98a436ddcc47c"), "x" : 1 }
> db.test.find({"_id" : ObjectId("4ecc05e55dd98a436ddcc47c")}) // explicit
{ "_id" : ObjectId("4ecc05e55dd98a436ddcc47c"), "x" : 1 }
> db.test.find(ObjectId...