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Mongodb Explain for Aggregation framework
...ther manipulation will be in-memory (possibly using temporary files if the allowDiskUse option is set).
Optimizing pipelines
In general, you can optimize aggregation pipelines by:
Starting a pipeline with a $match stage to restrict processing to relevant documents.
Ensuring the initial $match / ...
What is an ORM, how does it work, and how should I use one? [closed]
... case with a pseudo language:
You have a book class, you want to retrieve all the books of which the author is "Linus". Manually, you would do something like that:
book_list = new List();
sql = "SELECT book FROM library WHERE author = 'Linus'";
data = query(sql); // I over simplify ...
while (row ...
How do I test for an empty JavaScript object?
...do you post answer including jQuery if the question is not about jQuery at all?
– Eru
Oct 1 '12 at 14:10
48
...
Proper way to use **kwargs in Python
...*kwargs):
...etc...
this is not true. In the latter case, f can be called as f(23, 42), while the former case accepts named arguments only -- no positional calls. Often you want to allow the caller maximum flexibility and therefore the second form, as most answers assert, is preferable: but ...
Toggle button using two image on different state
...android:background="@null" and android:drawableRight="@drawable/check". Usually I've found toggle buttons are right-justified. If you need it left-justified, use android:drawableLeft
– Patrick
Jun 1 '15 at 10:39
...
Error: Jump to case label
...code, if foo equals 1, everything is ok, but if it equals 2, we'll accidentally use the i variable which does exist but probably contains garbage.
switch(foo) {
case 1:
int i = 42; // i exists all the way to the end of the switch
dostuff(i);
break;
case 2:
dostuff(i*2); // i is ...
printf with std::string?
...f what it expects definitely won't give you the results you want. It's actually undefined behaviour, so anything at all could happen.
The easiest way to fix this, since you're using C++, is printing it normally with std::cout, since std::string supports that through operator overloading:
std::cout...
Why isn't sizeof for a struct equal to the sum of sizeof of each member?
... errors.
Here's an example using typical settings for an x86 processor (all used 32 and 64 bit modes):
struct X
{
short s; /* 2 bytes */
/* 2 padding bytes */
int i; /* 4 bytes */
char c; /* 1 byte */
/* 3 padding bytes */
};
struct Y
{
int i; /* 4...
usr/bin/ld: cannot find -l
...
@ZoOo that shouldn't normally matter, the linker can work with either one
– djf
May 23 '13 at 9:48
...
Changing every value in a hash in Ruby
...
@Andrew Marshall Right you are, thanks. In Ruby 1.8, Hash.[] doesn't accept an array of array pairs, it requires an even number of direct arguments (hence the splat up front).
– Phrogz
Mar 4 '11 at 3...