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Iterating C++ vector from the end to the beginning
...;
i != my_vector.rend(); ++i ) {
}
rbegin()/rend() were especially designed for that purpose. (And yes, incrementing a reverse_interator moves it backward.)
Now, in theory, your method (using begin()/end() & --i) would work, std::vector's iterator being bidirectional, but remember,...
When to use enumerateObjectsUsingBlock vs. for
...
Ultimately, use whichever pattern you want to use and comes more naturally in the context.
While for(... in ...) is quite convenient and syntactically brief, enumerateObjectsUsingBlock: has a number of features that may or may not prove interesting:
enumerateObjectsUsingBlock: will be as fas...
Test if lists share any items in python
...
Short answer: use not set(a).isdisjoint(b), it's generally the fastest.
There are four common ways to test if two lists a and b share any items. The first option is to convert both to sets and check their intersection, as such:
bool(set(a) & set(b))
Because sets are stor...
Move capture in lambda
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Generalized lambda capture in C++14
In C++14 we will have the so called generalized lambda capture. This enables move capture. The following will be legal code in C++14:
using namespace std;
// a unique_ptr is move-only
auto u = make_unique<some_type>( some, parameters );
// move...
JavaScript: location.href to open in new window/tab?
...notification in modern browsers, doesn't simulate a _blank anchor click at all.
– Nathan Hornby
Oct 1 '14 at 12:46
22
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“ImportError: No module named” when trying to run Python script
...the notebook to operate from in your ipython_notebook_config.py file (typically using the c.NotebookManager.notebook_dir setting).
The solution is to provide the python interpreter with the path-to-your-module. The simplest solution is to append that path to your sys.path list. In your notebook, fi...
How is __eq__ handled in Python and in what order?
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The a == b expression invokes A.__eq__, since it exists. Its code includes self.value == other. Since int's don't know how to compare themselves to B's, Python tries invoking B.__eq__ to see if it knows how to compare itself to an int.
If you amend your ...
What predefined macro can I use to detect clang?
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To get a list of all the predefined macros that the compiler uses, use this:
clang -dM -E -x c /dev/null
You can do the same for gcc.
share
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python assert with and without parenthesis
...through IDLE. Because assert is a keyword and not a function, you are actually passing in a tuple as the first argument and leaving off the second argument.
Recall that non-empty tuples evaluate to True, and since the assertion message is optional, you've essentially called assert True when you wr...
How do I convert a Vector of bytes (u8) to a string
...("result: {}", s);
}
The conversion is in-place, and does not require an allocation. You can create a String from the string slice if necessary by calling .to_owned() on the string slice (other options are available).
The library reference for the conversion function:
std::str::from_utf8
...