std::ios_base::fmtflags

// using ios_base::fmtflags
#include <iostream>     // std::cout, std::ios_base, std::ios,
                        // std::hex, std::showbase
int main () {
  // using fmtflags as class member constants:
  std::cout.setf (std::ios_base::hex , std::ios_base::basefield);
  std::cout.setf (std::ios_base::showbase);
  std::cout << 100 << '\n';
  // using fmtflags as inherited class member constants:
  std::cout.setf (std::ios::hex , std::ios::basefield);
  std::cout.setf (std::ios::showbase);
  std::cout << 100 << '\n';
  // using fmtflags as object member constants:
  std::cout.setf (std::cout.hex , std::cout.basefield);
  std::cout.setf (std::cout.showbase);
  std::cout << 100 << '\n';
  // using fmtflags as a type:
  std::ios_base::fmtflags ff;
  ff = std::cout.flags();
  ff &= ~std::cout.basefield;   // unset basefield bits
  ff |= std::cout.hex;          // set hex
  ff |= std::cout.showbase;     // set showbase
  std::cout.flags(ff);
  std::cout << 100 << '\n';
  // not using fmtflags, but using manipulators:
  std::cout << std::hex << std::showbase << 100 << '\n';
  return 0;
}