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What do the plus and minus signs mean in Objective-C next to a method?
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answered Jan 19 '10 at 21:39
Georg SchöllyGeorg Schölly
113...
Multiple levels of 'collection.defaultdict' in Python
...ng specific that you need help with? When d[new_key] is accessed, it will call the lambda which will create a new defaultdict(int). And when d[existing_key][new_key2] is accessed, a new int will be created.
– interjay
Oct 11 '13 at 12:53
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How to compile a static library in Linux?
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target: prerequisites - the rule head
$@ - means the target
$^ - means all prerequisites
$< - means just the first prerequisite
ar - a Linux tool to create, modify, and extract from archives see the man pages for further information. The options in this case mean:
r - replace files existing...
Are HLists nothing more than a convoluted way of writing tuples?
I am really interested in finding out where the differences are, and more generally, to identify canonical use cases where HLists cannot be used (or rather, don't yield any benefits over regular lists).
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What are deferred objects?
...As of jQuery 1.5, the Deferred object provides a way to register multiple callbacks into self-managed callback queues, invoke callback queues as appropriate, and relay the success or failure state of any synchronous or asynchronous function.
Deferred Methods:
deferred.done()
Add handlers to be cal...
MongoDB/NoSQL: Keeping Document Change History
... changes to one or more specific entities in a database. I've heard this called row versioning, a log table or a history table (I'm sure there are other names for it). There are a number of ways to approach it in an RDBMS--you can write all changes from all source tables to a single table (more of...
MongoDB Many-to-Many Association
... user document:
{name:"Joe"
,roles:["Admin","User","Engineer"]
}
To get all the Engineers, use:
db.things.find( { roles : "Engineer" } );
If you want to maintain the roles in separate documents then you can include the document's _id in the roles array instead of the name:
{name:"Joe"
,roles:...
How to prevent gcc optimizing some statements in C?
...eeds. This has the advantage of just applying to a single function and not all functions defined in the same file.
Usage example:
void __attribute__((optimize("O0"))) foo(unsigned char data) {
// unmodifiable compiler code
}
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Changing the current working directory in Java?
...rt();
– CatsAndCode
Feb 9 '18 at 13:11
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Python argparse ignore unrecognised arguments
Optparse, the old version just ignores all unrecognised arguments and carries on. In most situations, this isn't ideal and was changed in argparse. But there are a few situations where you want to ignore any unrecognised arguments and parse the ones you've specified.
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