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pip installing in global site-packages instead of virtualenv
Using pip3 to install a package in a virtualenv causes the package to be installed in the global site-packages folder instead of the one in the virtualenv folder. Here's how I set up Python3 and virtualenv on OS X Mavericks (10.9.1):
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Java Enum definition
...? By making the type argument the new type itself. So if I've got an enum called StatusCode, it would be equivalent to:
public class StatusCode extends Enum<StatusCode>
Now if you check the constraints, we've got Enum<StatusCode> - so E=StatusCode. Let's check: does E extend Enum<S...
Java Reflection Performance
Does creating an object using reflection rather than calling the class constructor result in any significant performance differences?
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Is there a difference between copy initialization and direct initialization?
... expression is initialized to (loosely speaking) in C++17. These objects (called "result objects") are the variables created by a declaration (like a1), artificial objects created when the initialization ends up being discarded, or if an object is needed for reference binding (like, in A_factory_fun...
What exactly does stringstream do?
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To answer the question. stringstream basically allows you to treat a string object like a stream, and use all stream functions and operators on it.
I saw it used mainly for the formatted output/input goodness.
One good example would be c++ implementation of convert...
Track a new remote branch created on GitHub
...ame, you can just do git checkout <branchname> and git will automatically check it out and setup a tracking branch. Just wanted to reiterate what @Mark Longair said above in this comment: stackoverflow.com/questions/11262703/….
– Ryan Walls
Jan 23 '14 a...
iPhone 5 CSS media query
...Keep in mind it reacts the iPhone 5, not to the particular iOS version installed on said device.
To merge with your existing version, you should be able to comma-delimit them:
@media only screen and (max-device-width: 480px), only screen and (min-device-width: 560px) and (max-device-width: 1136px)...
Should I use pt or px?
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px ≠ Pixels
All of these answers seem to be incorrect. Contrary to intuition, in CSS the px is not pixels. At least, not in the simple physical sense.
Read this article from the W3C, EM, PX, PT, CM, IN…, about how px is a "magical" uni...
Appending an element to the end of a list in Scala
...'s because you shouldn't do it (at least with an immutable list).
If you really really need to append an element to the end of a data structure and this data structure really really needs to be a list and this list really really has to be immutable then do eiher this:
(4 :: List(1,2,3).reverse).rev...
What is the main difference between Inheritance and Polymorphism?
...class, then you have a Student class that extends Person, Student inherits all the things that Person has. There are some details around the access modifiers you put on the fields/methods in Person, but that's the basic idea. For example, if you have a private field on Person, Student won't see it...