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What does .SD stand for in data.table in R
...mples below, this is particularly helpful for chaining together "queries" (extractions/subsets/etc using [). In particular, this also means that .SD is itself a data.table (with the caveat that it does not allow assignment with :=).
The simpler usage of .SD is for column subsetting (i.e., when .SDc...
RAII and smart pointers in C++
...ance (and stealing an example from another answer):
void foo() {
std::string str;
// Do cool things to or using str
}
This works fine - but what if we want to return str? We could write this:
std::string foo() {
std::string str;
// Do cool things to or using str
return str;
}...
How can I indent multiple lines in Xcode?
...B instead, like eclipse and any derivatives
– Aram Kocharyan
Feb 9 '12 at 6:50
41
Additionally, C...
Set a persistent environment variable from cmd.exe
...stry key, then broadcast a WM_SETTINGCHANGE message with lParam set to the string "Environment". This allows applications, such as the shell, to pick up your updates.
You will of course need admin rights to do this. I know of no way to broadcast a windows message from Windows batch so you'll need...
Thread pooling in C++11
... func();
}
}
main.cpp
#include "function_pool.h"
#include <string>
#include <iostream>
#include <mutex>
#include <functional>
#include <thread>
#include <vector>
Function_pool func_pool;
class quit_worker_exception : public std::exception {};
void ...
How to read/write from/to file using Go?
...unc main() {
contents,_ := ioutil.ReadFile("plikTekstowy.txt")
println(string(contents))
ioutil.WriteFile("filename", contents, 0644)
}
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What represents a double in sql server?
... I'll be darn; you're right! I wonder what SQL does with the extra bit; it's not used for the exponent. If it did, the exponent would go up to +-616 instead of +-308. Maybe to track NULL?
– Euro Micelli
Jul 30 '09 at 21:42
...
What is the difference between Directory.EnumerateFiles vs Directory.GetFiles?
...merable which can be lazily evaluated somewhat, whereas GetFiles returns a string[] which has to be fully populated before it can return.
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Arrow operator (->) usage in C
...ore legible foo*.bar. The whole mess of typedef-ing functions with all the extra parentheses would have been avoided as well.
– Marquis of Lorne
Jan 26 '15 at 6:04
...
Angular IE Caching issue for $http
...
You can either append a unique querystring (I believe this is what jQuery does with the cache: false option) to the request.
$http({
url: '...',
params: { 'foobar': new Date().getTime() }
})
A perhaps better solution is if you have access to the serv...