I don’t think there was ever an actual decision to exclude iterators from bitset. Rather, bitset is one of the classes that predates the proposal to add the original Standard Template Library to the C++ standard. When it was designed, essentially none of the standard library included iterators. Then, Stepanov’s library was proposed for addition, …
With C++, the only way to iterate through enums is store them in an array and iterate through the same. The main challenge is how to track the same order in the enum declaration and the array declaration? You can automate the way you order them in the enum as well as array. I feel …
If Iterator is a random access iterator, then std::iterator_traits<Iterator>::iterator_category will be std::random_access_iterator_tag. The cleanest way to implement this is probably to create a second function template and have Foo call it: template <typename Iterator> void FooImpl(Iterator first, Iterator last, std::random_access_iterator_tag) { // … } template <typename Iterator> void Foo(Iterator first, Iterator last) { typedef typename …
C++ defines no such type as uint. This must be “your” type, i.e. a type defined in your code or some third party library. One can guess that it is the same as unsigned int. Could be unsigned long int though or something else. Anyway, you have to check it yourself. It is a matter …
You could use the std::advance method. #include <set> #include <algorithm> int main() { using namespace std; // generate a set… set<int> s; for( int i = 0; i != 10; ++i ) s.insert(i); auto r = rand() % s.size(); // not _really_ random auto n = *select_random(s, r); } Where template<typename S> auto select_random(const S …
Boost irange should really be the answer (ThxPaul Brannan) I’m adding my answer to provide a compelling example of very valid use-cases that are not served well by manual looping: #include <boost/range/adaptors.hpp> #include <boost/range/algorithm.hpp> #include <boost/range/irange.hpp> using namespace boost::adaptors; static int mod7(int v) { return v % 7; } int main() { std::vector<int> v; boost::copy( …
One approach is using Array.prototype.entries(): for (const [i, value] of arr.entries()) { if (i === arr.length – 1) { // do your thing } } Another way is keeping a count outside the loop like Shidersz suggested. I don’t think you want to check indexOf(item) though because that poses a problem if the last item …
An Iterator is a simple representation of a series of elements that can be iterated over. eg: List<String> list = Arrays.asList(“Apple”, “Banana”, “Orange”); Iterator<String> i = list.iterator(); i.next(); i.forEachRemaining(System.out::println); #output Banana Orange A Spliterator can be used to split given element set into multiple sets so that we can perform some kind of operations/calculations on …
The current accepted answer from @Ignacio Vazquez-Abrams is sufficient. However, others interested in this question may want to consider inheriting their class from an abstract base class (ABC) (such as those found in the standard module collections.abc). This does a number of things (there are probably others as well): ensures that all of the methods …
To give a code example, say you want to write an iterator that returns nothing if the source is null or empty. public IEnumerable<T> EnumerateThroughNull<T>(IEnumerable<T> source) { if (source == null) yield break; foreach (T item in source) yield return item; } Without the yield break it becomes impossible to return an empty set inside …