I have a loop for(aI = antiviral_data.begin(); aI != antiviral_data.end();) { for(vI = viral_data.begin(); vI != viral_data.end();) { if((*aI)->x == (*vI)->x && (*aI)->y == (*vI)->y) { vI = viral_data.erase(vI); aI = antiviral_data.erase(aI); } else { vI++; aI++; } } } But when ever antiviral_data contains a...
Hello all :) I need to get a reference to an iterator of a reference. However, my compiler is choking on this code: template <typename InputIterator> size_t iLongestBegin(InputIterator first, InputIterator last) { typedef typename std::iterator_traits<InputIterator>::reference SequenceT; //Problem is next line typedef t...
In C#, when writing a function that returns an IEnumerble<>, you can use yield return to return a single item of the enumeration and yield break; to signify no remaining items. What is the VB.NET syntax for doing the same thing? An example from the NerdDinner code: public IEnumerable<RuleViolation> GetRuleViolations() { if (String...
How is the implementation of Iterator in Java different from that in C++? ...
Hi, my_date_list = ['01', '02', '03','04','05','06','07','08','09','10','11','12','13','14','15','16','17','18','19','20','21','22','23','24','25','26','27','28','29','30','31'] str_date_list=[] for item in my_date_list: str_date_list.append(item+'-'+'05' + '-' +'09') counter= 0 i = iter(range(31)) for item in i: daily_user_sta...
I am a newbie, I have a question. I have a map. I have to loop through the map and build the iterator. Example: public Iterable<Test> getTests(Map<String, Test> testMap, Set<String> strings) { //loop tru the set of strings and build iterator. for(final String test1 : strings) { Test test = testMap.get(test1); ...
It often happens that I need to iterate over a list of strings in my C++ code. In languages like Perl, this is easy: foreach my $x ("abc", "xyz", "123") {.... } In the past, this is what I've done in C++ const char* strs[] = { "abc", "xyz", "123" }; for (int i=0; i<sizeof(strs)/sizeof(const char*); i++) { const char *str = strs[i...
I have a need for a "container" that acts like the following. It has 2 subcontainers, called A and B, and I need to be able to iterate over just A, just B, and A and B combined. I don't want to use extra space for redundant data, so I thought of making my own iterator to iterate over A and B combined. What is the easiest way to make your...
I have this code: set<int>::iterator new_end = set_difference(set1.begin(), set1.end(), set2.begin(), set2.end(), set1.begin()); set1.erase(new_end, set1.end); It compiles and runs fine in visual studio. However, in a previous question, people stat...
As the title asks. My understanding of a deque was that it allocated "blocks". I don't see how allocating more space invalidates iterators, and if anything, one would think that a deque's iterators would have more guarantees than a vector's, not less. ...
What advantages are there in accessing vector elements using an iterator vs an index? ...
Why does defining __getitem__ on a class make it iterable? For instance if I write: class b: def __getitem__(self, k): return k cb = b() for k in cb: print k I get the output: 0 1 2 3 4 5 6 7 8 ... I would really expect to see an error returned from "for k in cb:" ...
what is the exact different of both.. is using enumeration more benefit than using iterator..? can anyone elaborate.. any reference article would be appeciated ...
Consider: #include <map> int main() { std::map< int, int > m; m[ 0 ] = 0; m[ 1 ] = 1; m.erase( 0 ); // ok m.erase( 2 ); // no-op m.erase( m.find( 2 ) ); // boom! } (OK, so the title talks abouting erasing an end() iterator, but find will return end() for a non-existent key.) Why is erasing a non-existent ...
I have the following member data vector<State<T>*> activeChildren; I want to clean-up these pointers in my destructor StateContainer<T>::~StateContainer() { vector<State<T>*>::iterator it = activeChildren.begin(); while(it!=activeChildren.end()) { State<T>* ptr = *it; it = activeChildren.erase(it); delete ...
I have an object that has a list of 'observers'. These observers get notified of things, and they might respond to this change by adding or removing themselves or other observers from the object. I want a robust, and not unnecessarily slow, way to support this. class Thing { public: class Observer { public: virtual void o...
I have a BOOST_FOREACH loop to iterate over a list. Unfortunately, I also need to cache an iterator to a particular item. typedef List::iterator savedIterator; BOOST_FOREACH(Item &item, list) { // stuff... if (condition) savedIterator = &item; // this won't work // do more stuff... } Obviously I can do this using a list.b...
Here is a seemingly simple problem: given a list of iterators that yield sequences of integers in ascending order, write a concise generator that yields only the integers that appear in every sequence. After reading a few papers last night, I decided to hack up a completely minimal full text indexer in Python, as seen here (though that ...
I want to create a function that can take different types of iterators which store the same type of object: The first is a std::map containing shared_ptr<Foo> (typedef-ed as FooMap) and the other is a std::list which also contains shared_ptr<Foo> (FooList). I really like the solution MSalters suggested for a similar question and tried t...
I am getting the following error while migrating VC6 code to VS2008. This code works fine in VC6 but gives a compilation error in VC9. I know it is because of a compiler breaking change. What is the problem and how do I fix it? error C2440: 'initializing' : cannot convert from 'std::_Vector_iterator<_Ty,_Alloc>' to 'STRUCT_MUX...