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What's the $unwind operator in MongoDB?
..." } ,
{ author :"sam" , text : "this is bad" }
],
other : { foo : 5 }
}
Notice how tags is actually an array of 3 items, in this case being "fun", "good" and "fun".
What $unwind does is allow you to peel off a document for each element and returns that resulting document.
To think ...
What are inline namespaces for?
...r symbol name only.
Consider this example:
Suppose you write a function Foo that takes a reference to an object say bar and returns nothing.
Say in main.cpp
struct bar;
void Foo(bar& ref);
If you check your symbol name for this file after compiling it into an object.
$ nm main.o
T__ Z1f...
Correct way to delete cookies server-side
...se, have a look at cookies from other domains. For example, after deleting foo=bar; domain=www.example.com, an other cookie foo=qux; domain=.example.com will be used.
– Lekensteyn
Jun 26 '13 at 13:23
...
What's the rationale for null terminated strings?
...
char *temp = "foo bar"; is a valid statement in C... hey! isn't that a string? isn't it null terminated?
– Yanick Rochon
Dec 11 '10 at 20:22
...
Custom HTTP headers : naming conventions
... It's a matter of preference and name-spacing; concerns about "X-ClientDataFoo" being supported by any proxy or vendor without the "X" are clearly misplaced.
There's nothing special or magical about the "X-" prefix, but it helps to make it clear that it is a custom header. In fact, RFC-6648 et al h...
Type-juggling and (strict) greater/lesser-than comparisons in PHP
...$a <= $b and $b <= $a does not follow $a == $b:
var_dump(NAN <= "foo"); // bool(true)
var_dump("foo" <= NAN); // bool(true)
var_dump(NAN == "foo"); // bool(false)
PHP's <= operator is not transitive, i.e. from $a <= $b and $b <= $c does not follow $a <= $c (Example same as ...
How do servlets work? Instantiation, sessions, shared variables and multithreading
...ect thisIsThreadSafe;
thisIsNOTThreadSafe = request.getParameter("foo"); // BAD!! Shared among all requests!
thisIsThreadSafe = request.getParameter("foo"); // OK, this is thread safe.
}
}
See also:
What is the difference between JSF, Servlet and JSP?
Best option for Sessio...
How to read a (static) file from inside a Python package?
...irectory that itself is added to sys.path. E.g. with sys.path = [..., '.../foo', '.../bar.zip'], eggs go in .../foo, but packages in bar.zip can also be imported. You cant use pkg_resources to extract data from packages in bar.zip. I haven't checked if setuptools registers the necessary loader for i...
public friend swap member function
...unding namespace. For example, these were equivalent pre-standard:
struct foo
{
friend void bar()
{
// baz
}
};
// turned into, pre-standard:
struct foo
{
friend void bar();
};
void bar()
{
// baz
}
However, when ADL was invented this was removed. The friend fun...
Sorting dictionary keys in python [duplicate]
...
[v[0] for v in sorted(foo.items(), key=lambda(k,v): (v,k))]
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