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Is it possible to make abstract classes in Python?
...class is already established as abstract shouldn't the compiler/interpret know that all the methods are from the abstract class in question?
– Charlie Parker
Mar 17 '14 at 3:30
35
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Difference between Covariance & Contra-variance
...s T → IE<T>. Notice that this is a "thin arrow".
With me so far?
Now let's consider a relation. There is an assignment compatibility relationship between pairs of types in the first set. A value of type Tiger can be assigned to a variable of type Animal, so these types are said to be "assi...
Is it possible to do a sparse checkout without checking out the whole repository first?
...he possibility of whether Git would work well with this kind of repository now that it supports sparse checkouts but every example that I can find does the following:
...
Why doesn't 'ref' and 'out' support polymorphism?
...e, Giraffe, Turtle and Tiger, with the obvious subclassing relationships.
Now suppose you have a method void M(ref Mammal m). M can both read and write m.
Can you pass a variable of type Animal to M?
No. That variable could contain a Turtle, but M will assume that it contains only Mamma...
Is there a difference between “throw” and “throw ex”?
...link isn't being forwarded correctly after a blog migration. Looks like it now lives here. Edit: Hey, wait, that's your blog! Fix your own links! ;^D
– ruffin
Oct 8 '19 at 21:21
...
What Automatic Resource Management alternatives exist for Scala?
...
For now Scala 2.13 has finally supported: try with resources by using Using :), Example:
val lines: Try[Seq[String]] =
Using(new BufferedReader(new FileReader("file.txt"))) { reader =>
Iterator.unfold(())(_ => Option...
What's the fundamental difference between MFC and ATL?
... them yet.
[Edit embellishment: I did not work at Microsoft, so I don't know if Office was ever built on MFC, but I think the answer is no. Back in Win 3.1, Win 95 days, Office UI team would invent new controls, package them up in libraries, then the Windows and MFC teams would incorporate wrappe...
Change color of PNG image via CSS?
...image to grayscale, sepia and lot more (look at the example).
So you can now change the color of a PNG file with filters.
body {
background-color:#03030a;
min-width: 800px;
min-height: 400px
}
img {
width:20%;
float:left;
margin:0;
}
/*Filter styles*/
.sat...
ExecJS and could not find a JavaScript runtime
...
Heroku is now strongly discouraging therubyracer due to memory use. I installed nodejs on my dev machine per this answer and took therubyracer out of my gemfile. See also stackoverflow.com/questions/7092107/….
–...
What is a patch in git version control?
...TS)
See also Contributing to Rails with Git as another concrete example.
Nowadays, the GitHub pull request makes it really easy to apply patches on GitHub repos, which is useful when you aren't a direct contributor (ie you have no right to directly push to a repo).
Actually, fairly recently GitHub...