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What are Scala context and view bounds?
...rds, A should have an implicit conversion to B available, so that one can call B methods on an object of type A. The most common usage of view bounds in the standard library (before Scala 2.8.0, anyway), is with Ordered, like this:
def f[A <% Ordered[A]](a: A, b: A) = if (a < b) a else b
Be...
What does T&& (double ampersand) mean in C++11?
...e in the draft C++11 standard, but are not true for the final one! Specifically, it says at various points that rvalue references can bind to lvalues, which was once true, but was changed.(e.g. int x; int &&rrx = x; no longer compiles in GCC) – drewbarbs Jul 13 '14 at 16:12
The biggest d...
How to change the background color of the options menu?
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After spending a considerable amount of time trying all the options, the only way I was able to get an app using AppCompat v7 to change the overflow menu background was using the itemBackground attribute:
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar"&...
How to save a Python interactive session?
...ntly using Python's interpreter to work with databases, files, etc -- basically a lot of manual formatting of semi-structured data. I don't properly save and clean up the useful bits as often as I would like. Is there a way to save my input into the shell (db connections, variable assignments, lit...
Split (explode) pandas dataframe string entry to separate rows
...bine where Apply returns a dataframe of arbitrary size (but consistent for all chunks), and Combine just vstacks the returned DFs?
– Vincent
Oct 2 '12 at 0:22
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How can I add reflection to a C++ application?
...rate the data about each field(plus the field itself). This macro will be called like this:
REFLECTABLE
(
(const char *) name,
(int) age
)
So using Boost.PP we iterate over each argument and generate the data like this:
// A helper metafunction for adding const to a type
template<clas...
How to limit the maximum value of a numeric field in a Django model?
...ormer can be restricted to the number of decimal places stored and the overall number of characters stored, is there any way to restrict it to storing only numbers within a certain range, e.g. 0.0-5.0 ?
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Installing PIL with pip
I am trying to install PIL (the Python Imaging Library) using the command:
21 Answers
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How to check if a process id (PID) exists
...process is not owned by the running user, you may not have permissions to call kill -0. Better to use ps -p $PID > /dev/null 2>&1, which allows you to see process status, even if you do not have permissions to send a signal.
– mckoss
Apr 1 '12 at 16:...
How to remove trailing whitespace of all files recursively?
How can you remove all of the trailing whitespace of an entire project? Starting at a root directory, and removing the trailing whitespace from all files in all folders.
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