#include <fmt/ranges.h>
#include <sstream>
#include <generator>

std::generator<std::string&> istream_gen() {
  auto words = std::istringstream{"today is yesterday's tomorrow"};
  std::string word;
  while (words >> word)
    co_yield word;
}

int main() {
  fmt::print("{}\n", istream_gen());
}