Missing empty suffix iterator for std::regex_token_iterator?

I expect I'm misunderstanding the description at cppreference, but could someone explain why the following code:

std::regex comma(",");
std::string string("one,two,");
std::sregex_token_iterator begin{ string.begin(), string.end(), comma, -1 }, end;
for (auto it = begin; it != end; ++it)
{
    std::cout << "submatch = '" << it->str() << "'" << std::endl;
}

outputs just two submatches:

submatch = 'one'
submatch = 'two'

rather than also including an empty suffix iterator submatch for the empty string following the last comma?

submatch = ''

Encountered using Visual C++ 2017 and /std:c++17 if that makes any difference.