You can use the izip!() macro from the crate itertools, which implements this for arbitrary many iterators: use itertools::izip; fn main() { let a = [1, 2, 3]; let b = [4, 5, 6]; let c = [7, 8, 9]; // izip!() accepts iterators and/or values with IntoIterator. for (x, y, z) in izip!(&a, &b, … Read more
for uses iter(song) to loop; you can do this in your own code and then advance the iterator inside the loop; calling iter() on the iterable again will only return the same iterable object so you can advance the iterable inside the loop with for following right along in the next iteration. Advance the iterator … Read more
There is a fantastic package in Python called itertools. But before I get into that, it’d serve well to explain how the iteration protocol is implemented in Python. When you want to provide iteration over your container, you specify the __iter__() class method that provides an iterator type. “Understanding Python’s ‘for’ statement” is a nice … Read more
There is a solution with constant time complexity in C++11: for any sequence, associative, or unordered associative container (including all of the Standard Library containers), you can call the range-erase member function with an empty range: template <typename Container, typename ConstIterator> typename Container::iterator remove_constness(Container& c, ConstIterator it) { return c.erase(it, it); } The range-erase member … Read more
you need to iterate over dict.iteritems(): for k,v in d.iteritems(): # will become d.items() in py3k print “%s – %s” % (str(k), str(v)) Update: in py3 V3.6+ for k,v in d.items(): print (f”{k} – {v}”)
The get_data function returns an object. When used the way shown, that object will be a temporary object, which will be destructed once the full expression ends. The iterator now references a vector object which no longer exists, and can’t be dereferenced or used in any useful way.
The short answer is no. The long answer is still no, but it’s possible to hack it in a way that it sort of works. But to be clear, this is most certainly a hack. There are a few ways you can do it, but the common theme between them is that you want to … Read more
for-each is syntactic sugar for using iterators (approach 2). You might need to use iterators if you need to modify collection in your loop. First approach will throw exception. for (String i : list) { System.out.println(i); list.remove(i); // throws exception } Iterator it=list.iterator(); while (it.hasNext()){ System.out.println(it.next()); it.remove(); // valid here }
Is there any technical reason we couldn’t have front_emplacer, back_emplacer, and emplacer? No, there is no technical reason. As proof, here is a complete implementation of back_emplacer with a demo of your Use Case 1… #include <iterator> #include <vector> #include <iostream> template<class Container> class back_emplace_iterator : public std::iterator< std::output_iterator_tag, void, void, void, void > { … Read more
Had the same need so wrote a little class for it. Here are some examples: Generator<Integer> simpleGenerator = new Generator<Integer>() { public void run() throws InterruptedException { yield(1); // Some logic here… yield(2); } }; for (Integer element : simpleGenerator) System.out.println(element); // Prints “1”, then “2”. Infinite generators are also possible: Generator<Integer> infiniteGenerator = new … Read more