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Why does Python code run faster in a function?
...e names are assigned to indexes. This is possible because you can't dynamically add local variables to a function. Then retrieving a local variable is literally a pointer lookup into the list and a refcount increase on the PyObject which is trivial.
Contrast this to a global lookup (LOAD_GLOBAL), w...
What does auto&& tell us?
...value or rvalue expression and I will preserve its constness. This is typically used for forwarding (usually with T&&). The reason this works is because a "universal reference", auto&& or T&&, will bind to anything.
You might say, well why not just use a const auto& beca...
How to merge YAML arrays?
...hon:3.7.3
stage: test
script:
- *pip_git
- pip install -q -r requirements_test.txt
- python -m unittest discover tests
use the same `*pip_git` on e.g. build image...
where requirements_test.txt contains e.g.
-e git+ssh://git@gitlab.com/example/example.git@v0.2.2#e...
How to make my custom type to work with “range-based for loops”?
...hanges, and compilers that do not.
The objects returned do not have to actually be iterators. The for(:) loop, unlike most parts of the C++ standard, is specified to expand to something equivalent to:
for( range_declaration : range_expression )
becomes:
{
auto && __range = range_expressi...
Understanding the Use of ColorMatrix and ColorMatrixColorFilter to Modify a Drawable's Hue
...working on a UI for an app, and I'm attempting to use grayscale icons, and allow the user to change the theme to a color of their choosing. To do this, I'm trying to just apply a ColorFilter of some sort to overlay a color on top of the drawable. I've tried using PorterDuff.Mode.MULTIPLY, and it wor...
Why do we copy then move?
...rvalues, the above would not compile.
Won't a copy be expensive, especially given something like std::string?
If you pass an rvalue, that will be moved into str, and that will eventually be moved into data. No copying will be performed. If you pass an lvalue, on the other hand, that lvalue wil...
What is the Sign Off feature in Git for?
...nto the Linux kernel and a few other projects, but most projects don't actually use it.
It was introduced in the wake of the SCO lawsuit, (and other accusations of copyright infringement from SCO, most of which they never actually took to court), as a Developers Certificate of Origin. It is used to...
Can C++ code be valid in both C++03 and C++11 but do different things?
... // #1
void f(...); // #2
template<int N> void g() {
f(0*N); // Calls #2; used to call #1
}
Rounded results after integer division and modulo
In C++03 the compiler was allowed to either round towards 0 or towards negative infinity. In C++11 it is mandatory to round towards 0
int i = (-1) ...
Multi-gradient shapes
...intDrawable();
p.setShape(new RectShape());
p.setShaderFactory(sf);
Basically, the int array allows you to select multiple color stops, and the following float array defines where those stops are positioned (from 0 to 1). You can then, as stated, just use this as a standard Drawable.
Edit: Here's...
社交应用组件 · App Inventor 2 中文网
...ns a list of the most recent messages mentioning the logged-in user.
Initially, the list is empty. To set it, the program must:
Call the Authorize method.
Wait for the IsAuthorized event.
Call the RequestDirectMessages method.
4, Wait for the DirectMessagesReceived event.
...