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How should one use std::optional?
I'm reading the documentation of std::experimental::optional and I have a good idea about what it does, but I don't understand when I should use it or how I should use it. The site doesn't contain any examples as of yet which leaves it harder for me to grasp the true concept of this object. When...
What does the “at” (@) symbol do in Python?
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An @ symbol at the beginning of a line is used for class, function and method decorators.
Read more here:
PEP 318: Decorators
Python Decorators
The most common Python decorators you'll run into are:
@property
@classmethod
@staticmethod
If you see an @ in the middle of a line, that's ...
Which is more efficient: Multiple MySQL tables or one large table?
...inally it was set up in various tables meaning data is linked with UserIds and outputting via sometimes complicated calls to display and manipulate the data as required. Setting up a new system, it almost makes sense to combine all of these tables into one big table of related content.
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What is the difference between Elastic Beanstalk and CloudFormation for a .NET project?
I have developed a .NET MVC application and have started playing around with AWS and deploying it via the Visual Studio Toolkit. I have successfully deployed the application using the Elastic Beanstalk option in the toolkit.
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Ruby on Rails and Rake problems: uninitialized constant Rake::DSL
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A tweet from DHH earlier. Rake .9.0 breaks Rails and several other things, you need to:
gem "rake", "0.8.7"
in your Gemfile.
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Why call git branch --unset-upstream to fixup?
...topress is not under any development since 2011, it serves my purpose well and so I haven't thought of changing anything so far.
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how do I make a single legend for many subplots with matplotlib?
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There is also a nice function get_legend_handles_labels() you can call on the last axis (if you iterate over them) that would collect everything you need from label= arguments:
handles, labels = ax.get_legend_handles_labels()
fig.legend(handles, labels, loc='upper c...
Is it possible to declare two variables of different types in a for loop?
...se a structured binding declaration. The syntax has been supported in gcc and clang for years (since gcc-7 and clang-4.0) (clang live example). This allows us to unpack a tuple like so:
for (auto [i, f, s] = std::tuple{1, 1.0, std::string{"ab"}}; i < N; ++i, f += 1.5) {
// ...
}
The above...
Why start an ArrayList with an initial capacity?
...t 8 elements. Insert one (cost: 1). Insert two -- double, copy one element and insert two (cost: 2). Insert three -- double, copy two elements, insert three (cost: 3). Insert four (cost: 1). Insert five -- double, copy four elements, insert five (cost: 5). Insert six, seven and eight (cost: 3). Tota...
How to simulate a touch event in Android?
How to simulate a touch event with Android while giving the X and Y coordinates manually?
7 Answers
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