[pbsd]

Normal for loops can't really make that work, they're too general, but range for loops plausibly could. Something like

    for(auto&& e : range) {
        std::print("{}" e);
        join {
            std::print(", ");
        }
    }

where join {} is effectively syntax sugar for if(std::next(__first) != __last) {}.

The fmt library makes this sort of task easier by providing the join adaptor; this example would become

    fmt::print("{}", fmt::join(range, ", "));