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Checking if an instance's class implements an interface?
Given a class instance, is it possible to determine if it implements a particular interface? As far as I know, there isn't a built-in function to do this directly. What options do I have (if any)?
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Can't install Ruby under Lion with RVM – GCC issues
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This answer was edited multiple times and now contains several alternative solutions. Try the simple “Edit 3” solution first.
Ruby 1.9.3-p125 and later have official support for clang, so if you are installing such a version you should not need GCC. If you’re...
Concurrent HashSet in .NET Framework?
... you the same advantages than a HashSet<T> except key and value are different objects.
Source: Social MSDN
ConcurrentBag
If you don't mind about the duplicate entries, you can use the class ConcurrentBag<T> in the same namespace of the previous class.
private ConcurrentBag<string&...
How to create a directory using nerdtree
...s 'm'; you should see a menu at the bottom. Type in 'a' for add childnode. Now input the directory you want to create, making sure to add a '/' at the end, otherwise the script would create a file.
AFAIK NERDTree cannot create parent directories like 'mkdir -p' does.
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Should __init__() call the parent class's __init__()?
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In Python, calling the super-class' __init__ is optional. If you call it, it is then also optional whether to use the super identifier, or whether to explicitly name the super class:
object.__init__(self)
In case of object, calling the super method is not strictly necessary, sinc...
How to insert a SQLite record with a datetime set to 'now' in Android application?
...a couple options you can use:
You could try using the string "(DATETIME('now'))" instead.
Insert the datetime yourself, ie with System.currentTimeMillis()
When creating the SQLite table, specify a default value for the created_date column as the current date time.
Use SQLiteDatabase.execSQL to ins...
Hidden features of Scala
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trait Functor[F[_]] {
def fmap[A, B](f: A => B, fa: F[A]): F[B]
}
Now, if you have a Functor[List], you can map over lists. If you have a Functor[Tree], you can map over trees. But more importantly, if you have Functor[A] for any A of kind (*->*), you can map a function over A.
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.trim() in JavaScript not working in IE
...e under Mozilla, but an error displays when I try it in IE8. Does anyone know what is going on here? Is there anyway I can make it work in IE?
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Is there a simple, elegant way to define singletons? [duplicate]
... bound to the module, which could not be instantiated repeatedly anyway.
If you do wish to use a class, there is no way of creating private classes or private constructors in Python, so you can't protect against multiple instantiations, other than just via convention in use of your API. I would st...
Changes in import statement python3
...ollowing tree for example:
mypkg
├── base.py
└── derived.py
Now, your derived.py requires something from base.py. In Python 2, you could do it like this (in derived.py):
from base import BaseThing
Python 3 no longer supports that since it's not explicit whether you want the 'relati...