fix: output stream operator implementation fixed

src/core-io/include/units/quantity_io.h

@@ -54,6 +54,9 @@ std::basic_ostream<CharT, Traits>& operator<<(std::basic_ostream<CharT, Traits>&
   if(os.width()) {
     // std::setw() applies to the whole quantity output so it has to be first put into std::string
     std::basic_ostringstream<CharT, Traits> s;
+    s.flags(os.flags());
+    s.imbue(os.getloc());
+    s.precision(os.precision());
     detail::to_stream(s, q);
     return os << s.str();
   }