Question

I got a piece of code like this:

template<class Iter>
void printRange(Iter begin, Iter last) {
    for (Iter i = begin; i != last; i++) {
        std::cout << *i << ", ";
    }
     outstd::cout << *last << ", ";
}

My question is: how can i print out the last element, too, elegantly? Couting the last element individually after the loop does not seem to be a nice and correct solution, … Is there a better way? Note that i cannot use the <= operator or boost or any stl specific feature either.

Answer 1

You can output the separator conditionally:

template<class Iter>
void printContainer(Iter first, Iter last) {
    for (Iter i = first, end = ++last; i != end; i++) {
        std::cout << (i == first ? "" : ", ") << *i;
    }
}

For a more standard [begin, end) half-open range:

template<class Iter>
void printContainer(Iter begin, Iter end) {
    for (Iter i = begin; i != end; i++) {
        std::cout << (i == begin ? "" : ", ") << *i;
    }
}