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How do I declare an array of weak references in Swift?
...T] {
return objects.flatMap { $0.object }
}
func contains(_ object: T) -> Bool {
return self.objects.contains(WeakObject(object: object))
}
func addObject(_ object: T) {
self.objects.formUnion([WeakObject(object: object)])
}
func addObjects(_ obj...
How do you send a HEAD HTTP request in Python 2?
...rt urllib2
>>> class HeadRequest(urllib2.Request):
... def get_method(self):
... return "HEAD"
...
>>> response = urllib2.urlopen(HeadRequest("http://google.com/index.html"))
Headers are available via response.info() as before. Interestingly, you can find the URL th...
WARN Could not determine content-length of response body. Set content-length of the response or set
...d of Webrick, and the warn will disappear.
– fearless_fool
Aug 3 '12 at 3:55
2
I second using thi...
Set value to NULL in MySQL
... can be inserted/updated without quotes:
INSERT INTO user (name, something_optional) VALUES ("Joe", NULL);
UPDATE user SET something_optional = NULL;
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...
Find MongoDB records where array field is not empty
...unexpected results. For example: db.doc.find({'nums': { $gt: [] }}).hint({ _id: 1 }).count() returns the right number, while db.doc.find({'nums': { $gt: [] }}).hint({ nums: 1 }).count() returns 0.
– wojcikstefan
Mar 4 '17 at 17:51
...
UILabel sizeToFit doesn't work with autolayout ios6
...s = [NSLayoutConstraint constraintsWithVisualFormat:@"|-8-[descriptionLabel_]-8-|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(descriptionLabel_)];
[self addConstraints:constrs];
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-8-[descriptionLabel_]" options:...
New self vs. new static
...the first method, whereas static is bound to the called class (also see get_called_class()).
class A {
public static function get_self() {
return new self();
}
public static function get_static() {
return new static();
}
}
class B extends A {}
echo get_class(B::ge...
Scala @ operator
...n itself? That would be accomplished with this:
o match {
case x @ Some(_) => println(x)
case None =>
}
Note that @ can be used at any level, not just at the top level of the matching.
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...
Curly braces in string in PHP
...eral {$. Some examples to make it clear:
<?php
// Show all errors
error_reporting(E_ALL);
$great = 'fantastic';
// Won't work, outputs: This is { fantastic}
echo "This is { $great}";
// Works, outputs: This is fantastic
echo "This is {$great}";
echo "This is ${great}";
// Works
echo "This sq...
awk without printing newline
...
awk '{sum+=$3}; END {printf "%f",sum/NR}' ${file}_${f}_v1.xls >> to-plot-p.xls
print will insert a newline by default. You dont want that to happen, hence use printf instead.
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