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Concurrent HashSet in .NET Framework?
...can use a simple 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
Concurrent...
What are the details of “Objective-C Literals” mentioned in the Xcode 4.4 release notes?
...Array, NSDictionary, and NSNumber (just like one can create literals for NSString)
NSArray Literals
Previously:
array = [NSArray arrayWithObjects:a, b, c, nil];
Now:
array = @[ a, b, c ];
NSDictionary Literals
Previously:
dict = [NSDictionary dictionaryWithObjects:@[o1, o2, o3]
...
How to access outer class from an inner class?
...ontainer()
self.<sub_class> = subclasses[<sub_class, type string>]
del subclasses
def _subclass_container(self):
_parent_class = self
class <sub_class>:
def __init__(self):
self._parent_class = _parent_class
r...
Count(*) vs Count(1) - SQL Server
...ution-time work. The Compilation time work is a trivially small amount of extra work in the current implementation. There is an expansion of the * to all columns in some cases followed by a reduction back to 1 column being output due to how some of the internal operations work in binding and optim...
Reference — What does this symbol mean in PHP?
...
@AcidShout $a - $b works for numbers, but not strings, objects, or arrays.
– mcrumley
Sep 25 '15 at 18:29
49
...
Python Requests and persistent sessions
... loginData,
loginTestUrl,
loginTestString,
sessionFileAppendix = '_session.dat',
maxSessionTimeSeconds = 30 * 60,
proxies = None,
userAgent = 'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:40.0) Geck...
What's Mongoose error Cast to ObjectId failed for value XXX at path “_id”?
...ast fails.
This doesn't happen with 41224d776a326fb40f000001 because that string is a valid ObjectId.
One way to resolve this is to add a check prior to your findById call to see if id is a valid ObjectId or not like so:
if (id.match(/^[0-9a-fA-F]{24}$/)) {
// Yes, it's a valid ObjectId, procee...
Are loops really faster in reverse?
...
i-- is as fast as i++
This code below is as fast as yours, but uses an extra variable:
var up = Things.length;
for (var i = 0; i < up; i++) {
Things[i]
};
The recommendation is to NOT evaluate the size of the array each time. For big arrays one can see the performance degradation.
...
No submodule mapping found in .gitmodule for a path that's not a submodule
...
in the file .gitmodules, I replaced string
"path = thirdsrc\boost"
with
"path = thirdsrc/boost",
and it solved! - -
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...
How to decide font color in white or black depending on background color?
...Color, darkColor) {
var color = (bgColor.charAt(0) === '#') ? bgColor.substring(1, 7) : bgColor;
var r = parseInt(color.substring(0, 2), 16); // hexToR
var g = parseInt(color.substring(2, 4), 16); // hexToG
var b = parseInt(color.substring(4, 6), 16); // hexToB
return (((r * 0.299) + (g * ...