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Virtual functions and performance - C++
In my class design, I use abstract classes and virtual functions extensively. I had a feeling that virtual functions affects the performance. Is this true? But I think this performance difference is not noticeable and looks like I am doing premature optimization. Right?
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How to understand nil vs. empty vs. blank in Ruby
I find myself repeatedly looking for a clear definition of the differences of nil? , blank? , and empty? in Ruby on Rails. Here's the closest I've come:
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Dynamic variable names in Bash
...mic variable names:
declare "magic_variable_$1=$(ls | tail -1)"
and use indirect parameter expansion to access the value.
var="magic_variable_$1"
echo "${!var}"
See BashFAQ: Indirection - Evaluating indirect/reference variables.
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Best Practices: working with long, multiline strings in PHP?
...mely simple question but I'm somewhat obsessive compulsive over the formatting of my code.
10 Answers
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How do I find out what version of WordPress is running?
I have just taken over someone's hosted WordPress site. How do I find out what version he is running?
16 Answers
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Should you declare methods using overloads or optional parameters in C# 4.0?
I was watching Anders' talk about C# 4.0 and sneak preview of C# 5.0 , and it got me thinking about when optional parameters are available in C# what is going to be the recommended way to declare methods that do not need all parameters specified?
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When should I really use noexcept?
...o many function signatures, but I am unsure as to when I should consider using it in practice. Based on what I have read so far, the last-minute addition of noexcept seems to address some important issues that arise when move constructors throw. However, I am still unable to provide satisfactory a...
Using pip behind a proxy with CNTLM
I am trying to use pip behind a proxy at work.
32 Answers
32
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Sort a list by multiple attributes?
... = sorted(s, key = lambda x: (x[1], x[2]))
Or you can achieve the same using itemgetter (which is faster and avoids a Python function call):
import operator
s = sorted(s, key = operator.itemgetter(1, 2))
And notice that here you can use sort instead of using sorted and then reassigning:
s.sort...
What does the term “porcelain” mean in Git?
The term "porcelain" appears occasionally in the Git documentation. What does it mean?
9 Answers
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