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Convert base class to derived class [duplicate]
Is it possible in C# to explicitly convert a base class object to one of it's derived classes? Currently thinking I have to create a constructor for my derived classes that accept a base class object as a parameter and copy over the property values. I don't really like this idea, so I'd like to avoi...
What is the easiest way to duplicate an activerecord record?
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To get a copy, use the clone (or dup for rails 3.1+) method:
# rails < 3.1
new_record = old_record.clone
#rails >= 3.1
new_record = old_record.dup
Then you can change whichever fields you want.
ActiveRecord overrides the built-in Object#cl...
Parsing boolean values with argparse
...;bool>
and still use a default value (specific to the user settings). One (indirectly related) downside with that approach is that the 'nargs' might catch a positional argument -- see this related question and this argparse bug report.
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Asynchronous vs Multithreading - Is there a difference?
...ase, an asynchronous call does not necessarily create a new thread. That's one way to implement it, with a pre-existing thread pool or external process being other ways. It depends heavily on language, object model (if any), and run time environment.
Asynchronous just means the calling thread doesn...
Convert Rows to columns using 'Pivot' in SQL Server
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This is fantastic - nice one @bluefeet. I'd never used STUFF(...) before (or the XML PATH either). For the benefit of other readers, all that is doing is joining the column names and chopping off the leading comma. Note I think the following is slig...
Move branch pointer to different commit without checkout
To move the branch pointer of a checked out branch, one can use the git reset --hard command. But how to move the branch pointer of a not-checked out branch to point at a different commit (keeping all other stuff like tracked remote branch)?
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Split a collection into `n` parts with LINQ?
...believe there's a built-in way of partitioning, although I intend to write one in my set of additions to LINQ to Objects. Marc Gravell has an implementation here although I would probably modify it to return a read-only view:
public static IEnumerable<IEnumerable<T>> Partition<T>
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How can I add an item to a IEnumerable collection?
...specified type), which, when enumerated, will provide all items of the old one, plus some of your own. You use Enumerable.Concat for that:
items = items.Concat(new[] { "foo" });
This will not change the array object (you cannot insert items into to arrays, anyway). But it will create a new objec...
Matplotlib different size subplots
I need to add two subplots to a figure. One subplot needs to be about three times as wide as the second (same height). I accomplished this using GridSpec and the colspan argument but I would like to do this using figure so I can save to PDF. I can adjust the first figure using the figsize ar...
Request failed: unacceptable content-type: text/html using AFNetworking 2.0
...jaytrixz comment is to just add a new content type to the already existing ones: op.responseSerializer.acceptableContentTypes = [op.responseSerializer.acceptableContentTypes setByAddingObject:@"text/html"];
– mgarciaisaia
Jul 3 '14 at 17:12
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