optional_of_optional.cpp

#include <optional>
#include <cstdio>
int main() {
  
  std::optional<int> optional_of_none(std::nullopt);
  std::optional<std::optional<int>> optional_of_optional(optional_of_none);
  
  std::printf(
    "optional_of_none.has_value():\t%d\n"
    "optional_of_optional.has_value():\t%d\n",
    optional_of_none.has_value(), optional_of_optional.has_value()
  );
  
  return 0;
}