Iterating a vector to second to last element with index vs iterator

When iterating from the beginning of a C++11 std::vector to the second to last element, what would be the preferred style?

std::vector<const char*> argv;
std::string str;

Should this kind of more C++-esque method be used

for (const auto& s: decltype(argv)(argv.begin(), argv.end()-1)) {
    str += std::string(s) + ' ';
}

or should the more traditional way be preferred?

for (size_t i = 0; i < argv.size() - 1; ++i) {
    str += std::string(argv[i]);
}