C ++相当于python的itertools :: cycle

Question

Is there a C++ class (or libboost class) similar to python's itertools::cycle ?

I am looking for a container class that I can "roll" or "shift in a cycle". Example with integers :

MyCont = {{1,2,3}}
MyCont.roll()  // MyCont now holds {{2,3,1}}
cout << MyCont[0] << endl; // returns 2
cout << MyCont[1] << endl; // returns 3

Do I need to implement it myself, or is there an existing implementation somewhere ?

Edit

The above example demonstrates the behaviour I am looking for, but my case is slightly more difficult : my container holds objects, each of them embedding a large array. I want to reorder the container's items without performing deep copies. What is the best way to do so ?

Answer 1

Yes. There is rotate in algorithms.

For your updated issue you are correct in thinking to hold pointers to the objects in an array and rotate them. Or you could try list and use the internal swap method which "Does not invoke any move, copy, or swap operations on individual elements." or the specialisation of swap for lists