text: //===----------------------------------------------------------------------===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is dual licensed under the MIT and the University of Illinois Open
  // Source Licenses. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  
  // <chrono>
  
  // duration
  
  // template <class Rep1, class Period1, class Rep2, class Period2>
  //   typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type
  //   operator+(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
  
  #include <chrono>
  #include <cassert>
  
  int main()
  {
      {
      std::chrono::seconds s1(3);
      std::chrono::seconds s2(5);
      std::chrono::seconds r = s1 + s2;
      assert(r.count() == 8);
      }
      {
      std::chrono::seconds s1(3);
      std::chrono::microseconds s2(5);
      std::chrono::microseconds r = s1 + s2;
      assert(r.count() == 3000005);
      }
      {
      std::chrono::duration<int, std::ratio<2, 3> > s1(3);
      std::chrono::duration<int, std::ratio<3, 5> > s2(5);
      std::chrono::duration<int, std::ratio<1, 15> > r = s1 + s2;
      assert(r.count() == 75);
      }
      {
      std::chrono::duration<int, std::ratio<2, 3> > s1(3);
      std::chrono::duration<double, std::ratio<3, 5> > s2(5);
      std::chrono::duration<double, std::ratio<1, 15> > r = s1 + s2;
      assert(r.count() == 75);
      }
  }
  