Removing a comma from a c++ output

Question

I wrote this program that sorts numbers in vectors from greatest to least, it works great but the only thing that is bugging me is trying to remove the comma from the last n

Answer 1

If begin, end are at least bidirectional iterators (as yours are), you can just check initially that begin != end; if not print nothing; if so print ", "-puncuated elements incrementing begin != std::prev(end), and finally print *begin(). like so:

main.cpp

#include 

template
void punctuated(OStream && out, Punct && punct, BiIter begin, BiIter end)
{
    if (begin != end) {
        for (--end  ;begin != end; ++begin) {
            std::forward(out) << *begin << std::forward(punct);
        }
        std::forward(out) << *begin;
    }
}

#include 
#include 
#include 
#include 

int main()
{
    std::vector v0;
    std::vector v1{{1}};
    std::list l{{1,2}};
    std::sets{{3,4,5,6,7}};
    std::cout << "v0 [";
    punctuated(std::cout,",",v0.begin(),v0.end());
    std::cout << "]\n";
    std::cout << "v1 [";
    punctuated(std::cout,",",v1.begin(),v1.end());
    std::cout << "]\n";
    std::cout << "l [";
    punctuated(std::cout,",",l.begin(),l.end());
    std::cout << "]\n";
    std::cout << "s [";
    punctuated(std::cout,"|",s.begin(),s.end());
    std::cout << "]\n";
    return 0;
}

Output:

g++ -Wall -Wextra main.cpp && ./a.out
v0 []
v1 [1]
l [1,2]
s [3|4|5|6|7]

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