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Swift native base class or NSObject
...r by using the '@objc' decoration. Otherwise it will follow a static- and vtable-dispatch style, like C++.
6 Answers
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How can I use NSError in my iPhone App?
... // init dictionary to be used to populate error object
NSMutableDictionary* details = [NSMutableDictionary dictionary];
[details setValue:@"ran out of money" forKey:NSLocalizedDescriptionKey];
// populate the error object with the details
*error = [NSError err...
Simplest way to profile a PHP script
...m query");
// Get all the data
$select_query = "SELECT * FROM data_table";
$result = mysql_query($select_query);
prof_flag("Retrieve data");
$rows = array();
$found_data=false;
while($r = mysql_fetch_assoc($result))
{
$found_data=true;
$rows[] = $r;
}
prof_...
How to calculate the CPU usage of a process by PID in Linux from C?
...w fields (from Documentation/filesystems/proc.txt in your kernel source):
Table 1-3: Contents of the stat files (as of 2.6.22-rc3)
..............................................................................
Field Content
pid process id
tcomm filename of the execut...
Why should I declare a virtual destructor for an abstract class in C++?
...t a virtual destructor.
You will eventually end up with no virtual method table, and end up signalling your clients your intention on making it non-deleteable through a pointer to it, so you have indeed reason not to declare it virtual in those cases.
[See item 4 in this article: http://www.gotw....
What are '$$' used for in PL/pgSQL
...is +999 999'';
END IF;
RETURN true;
END
' LANGUAGE plpgsql STRICT IMMUTABLE;
This isn't such a good idea. Use dollar-quoting instead, more specifically also put a token between the $$ to make it unique - you might want to use $-quotes inside the function body, too. I do that a lot, actually.
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Why does sun.misc.Unsafe exist, and how can it be used in the real world?
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VM "intrinsification." ie CAS (Compare-And-Swap) used in Lock-Free Hash Tables
eg:sun.misc.Unsafe.compareAndSwapInt
it can make real JNI calls into native code that contains special instructions for CAS
read more about CAS here http://en.wikipedia.org/wiki/Compare-and-swap
The sun.misc.Unsafe fu...
Solr vs. ElasticSearch [closed]
...Maturity: Solr is more mature, but ES has grown rapidly and I consider it stable
Performance: hard to judge. I/we have not done direct performance benchmarks. A person at LinkedIn did compare Solr vs. ES vs. Sensei once, but the initial results should be ignored because they used non-expert setup ...
Non-static method requires a target
...rties. If there are Foreign Key references (Navigation Properties) between tables and you use those references in your lambda (e.g. ProductDetail.Products.ID) then that "Products" context remains null if you manually created the Entity.
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Get key by value in dictionary
...he problem can be easily generalised. For example you could have a look up table with unique keys and their corresponding unique values. You can then look up things symmetrically value --> key or key --> value
– pfabri
May 13 at 16:34
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