I have question with this same title here but now as I'll present in code below this seems to behave in the opposite way to the way explained to me in my first question with the same title. Ok code: class LINT_rep { private: char* my_data_; //stores separately every single digit from a number public: class Iterator:public iterat...
Hi, Performance wise, is there really a big difference between using: ArrayList.contains(o) vs foreach|iterator LinkedList.contains(o) vs foreach|iterator Of course, for the foreach|iterator loops, I'll have to explicitly compare the methods and return true or false accordingly. The object I'm comparing is an object where equals() ...
What is Iterator and collections? Does these two have any relations? // the interface definition Interface Iterator { boolean hasNext(); Object next(); // note "one-way" traffic void remove(); } // an example public static void main (String[] args){ ArrayList cars = new ArrayList(); for (int i = 0; i < 12; i++) cars.add (new Car()); I...
I have 3 classes, 2 inheriting from the other like so: class A { public: virtual void foo() {cout << "I am A!" << endl;} }; class B : public A { public: void foo() {cout << "B pretending to be A." << endl} void onlyBFoo() {cout << "I am B!" << endl} }; class C : public A { public: void foo() {cout << "C pretendin...
Hi there, I have a csv DictReader object (using Python 3.1), but I would like to know the number of lines/rows contained in the reader before I iterate through it. Something like as follows... myreader = csv.DictReader(open('myFile.csv', newline='')) totalrows = ? rowcount = 0 for row in myreader: rowcount +=1 print("Row %d/...
I'd like to know if there is a class available, either in the standard library or in pypi, that fits this description. The constructor would take an iterator. It would implement the container protocol (ie _getitem_, _len_, etc), so that slices, length, etc., would work. In doing so, it would iterate and retain just enough values from ...
I have a function where I have a container which holds strings (eg vector<string>, set<string>, list<string>) and, given a start iterator and an end iterator, go through the iterator range processing the strings. Currently the function is declared like this: template< typename ContainerIter> void ProcessStrings(ContainerIter begin, Co...
If I have a class that contains a std::list<Foo> and which has public methods begin() and end() to return iterators for that list, how can I implement additional methods to return iterators to a std::list<Foo*>, preferably without using boost? I'd rather not maintain a parallel container of pointers. Edit: I have a large code base tha...
I'm making a simple command line Hangman game. void Hangman::printStatus() { cout << "Lives remaining: " << livesRemaining << endl; cout << getFormattedAnswer() << endl; } string Hangman::getFormattedAnswer() { return getFormattedAnswerFrom(correctAnswer.begin(), correctAnswer.end()); } string Hangman::getFormattedAnswerFr...
I would like to call 'contains' on my Iterables :-) ...
I'm working on a GWT project, and I have a bunch of Java classes that use Java Object Iterators on the server side. As I was reading through the internet...Iterators seem to not be serializable preventing me from sending them over to the client side from the server side. My question is is there an efficient way to serialize the iterator ...
I'm learning C++ and I am writing a function that determines whether a string contains only alphanumeric characters and spaces. I suppose I am effectively testing whether it matches the regular expression ^[[:alnum:] ]+$ but without using regular expressions. I have seen a lot of algorithms revolve around iterators, so I tried to find a ...
in the following code: int utf8len(char* s, int len) { Glib::ustring::iterator p( string::iterator(s) ); Glib::ustring::iterator e ( string::iterator(s+len) ); int i=0; for (; p != e; p++) // ERROR HERE! i++; return i; } I get the compiler error on the for line, which is sometimes "invalid lvalue in increment", and sometimes...
I might be doing this wrong, if I am, let me know, but I'm curious if the following is possible: I have a class that holds a number of dictionaries, each of which pairs names to a different set of objects of a given class. For example: items = {"ball" : ItemInstance1, "sword" : ItemInstance2} people = {"Jerry" : PersonInstance1, "Bob" ...
I've been working on writing a library in my spare time to familiarize myself more with c++ and singular value decomposition. I've been working on writing an Iterator class and I'm entirely capable of writing the functionality and I have already for my own currently MatrixIterator class. I'm guessing that it involves namespaces because: ...
So I have a one list box with values like DeptA, DeptB, DeptC & DeptD. I have a method that causes these to automatically populate in this list box if they are applicable. So in other words, if they populate in this list box, I want the resulting logic to say they are "Yes" in a boolean field in the table. So to accomplish this I am try...
Hi, I'm trying to use BOOST_FOREACH for iterating through the std::queue. But there isn't iterators in that class cause I have an error: std::queue<std::string> someList; BOOST_FOREACH(std::string temp, someList) { std::cout << temp; } >no matching function for call to begin(...) >no type named ‘iterator’ in ‘class std::queue<std::b...
I am mixing some C and C++ libraries and have only a single pointer available to do some work in a callback function. All I need to do is iterate through a vector. Here's a simplified, untested example: bool call_back(void* data){ done=... if (!done) cout << *data++ << endl; return done; } Note that this function is in an ext...
Hi, Can any one recommend a good resource to refer on writing C++ custom template iterators?? Thank You! ...
Hi, I have a Red Black tree implemented in c++. It supports the functionality of a STL map. Tree nodes contain keys and the values mapped. I want to write an iterator class for this, but I'm stuck with how to do it. Should I make it an inner class of the Tree class? Can anyone give me some guidelines on how to write it + some resources...