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How many GCC optimization levels are there?
...lear on the man page.
We shall conclude that:
anything above -O3 up to INT_MAX is the same as -O3, but that could easily change in the future, so don't rely on it.
GCC 5.1 runs undefined behavior if you enter integers larger than INT_MAX.
the argument can only have digits, or it fails gracefully. I...
Bash continuation lines
...here document. (Line terminators will still remain, though.)
cat <<-____HERE
continuation
lines
____HERE
See also http://ss64.com/bash/syntax-here.html
If you need to preserve some, but not all, leading whitespace, you might use something like
sed 's/^ //' <<____HERE
Th...
Code Golf: Collatz Conjecture
...t;^v are arrows that change direction the "program counter" wanders. | and _ are conditionals that go up/down or left/right depending on whether the value on stack is true or false. The whole "code arena" wraps around through top-bottom and left-right.
– SF.
Ma...
Concurrent HashSet in .NET Framework?
...byte (1 byte in memory).
private ConcurrentDictionary<string, byte> _data;
This is the recommended option because the type is thread-safe and provide you the same advantages than a HashSet<T> except key and value are different objects.
Source: Social MSDN
ConcurrentBag
If you don't...
Getting the SQL from a Django QuerySet [duplicate]
...et = MyModel.objects.all()
>>> print(queryset.query)
SELECT "myapp_mymodel"."id", ... FROM "myapp_mymodel"
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The tilde operator in Python
...s operator.invert. To support this operator in your own class, give it an __invert__(self) method.
>>> import operator
>>> class Foo:
... def __invert__(self):
... print 'invert'
...
>>> x = Foo()
>>> operator.invert(x)
invert
>>> ~x
invert
Any ...
Add CSS or JavaScript files to layout head from views or partial views
...Format);
}
}
public class ItemRegistrar
{
private readonly string _format;
private readonly IList<string> _items;
public ItemRegistrar(string format)
{
_format = format;
_items = new List<string>();
}
public ItemRegistrar Add(string url)
...
How do I perform the SQL Join equivalent in MongoDB?
...ttps://docs.mongodb.org/master/reference/operator/aggregation/lookup/#pipe._S_lookup
From the docs:
{
$lookup:
{
from: <collection to join>,
localField: <field from the input documents>,
foreignField: <field from the documents of the "from" collection>...
How to convert a scala.List to a java.util.List?
...1,2,3))
From Scala 2.8 onwards:
import scala.collection.JavaConversions._
import scala.collection.mutable.ListBuffer
asList(ListBuffer(List(1,2,3): _*))
val x: java.util.List[Int] = ListBuffer(List(1,2,3): _*)
However, asList in that example is not necessary if the type expected is a Java List,...
IOCTL Linux device driver [closed]
...ion from and to the driver. An example of how to set this up:
static ssize_t mydrvr_version_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "%s\n", DRIVER_RELEASE);
}
static DEVICE_ATTR(version, S_IRUGO, mydrvr_version_show, NULL);
And during ...