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Can PostgreSQL index array columns?
... to this question in the documentation. If a column is an array type, will all the entered values be individually indexed?
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In which situations do we need to write the __autoreleasing ownership qualifier under ARC?
...ents that are passed by reference (id *) and are autoreleased on return.
All of this is very well explained in the ARC transition guide.
In your NSError example, the declaration means __strong, implicitly:
NSError * e = nil;
Will be transformed to:
NSError * __strong error = nil;
When you c...
Why does SSL handshake give 'Could not generate DH keypair' exception?
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This works for me too, but I have added a provider dynamically. Reffer my answer here for details.
– v.ladynev
Nov 22 '15 at 9:19
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Python: Is it bad form to raise exceptions within __init__?
...t have been designed with exception safety in mind, the destructor is not called if an exception is thrown in the constructor of an object (meaning that the initialization of the object is incomplete). This is often not the case in scripting languages, such as Python. For example, the following code...
Where can I get a list of Ansible pre-defined variables?
...h0.ipv4.address. Googleing and searching the docs I cound't find a list of all available variables. Would someone list them for me?
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Calling a class function inside of __init__
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Call the function in this way:
self.parse_file()
You also need to define your parse_file() function like this:
def parse_file(self):
The parse_file method has to be bound to an object upon calling it (because it's not a ...
How to model type-safe enum types?
...ample above) does not offer exhaustive pattern matching. I have researched all the different enumeration patterns currently being used in Scala and give and overview of them in this StackOverflow answer (including a new pattern which offers the best of both scala.Enumeration and the "sealed trait +...
Is there an online name demangler for C++? [closed]
...d implementations of demanglers are horribly buggy and insecure. They basically only work on mangled names that the same platform produced, but may run into high complexity or flat out memory errors on general inputs.
– Kerrek SB
Mar 29 '17 at 0:07
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Delimiters in MySQL
...s it through a programming language API to MySQL. Some other clients like PHPMyAdmin have other methods to specify a non-default delimiter.
Example:
DELIMITER $$
/* This is a complete statement, not part of the procedure, so use the custom delimiter $$ */
DROP PROCEDURE my_procedure$$
/* Now start...
How is a CRC32 checksum calculated?
... 1 0000 0100 1100 0001 0001 1101 1011 0111
The highest term (x32) is usually not explicitly written, so it can instead be represented in hex just as
0x 04 C1 1D B7
Feel free to count the 1s and 0s, but you'll find they match up with the polynomial, where 1 is bit 0 (or the first bit) and x ...