op_plus.md

operator+

• chrono[meta header]
• std::chrono[meta namespace]
• function template[meta id-type]
• cpp11[meta cpp]

namespace std {
namespace chrono {
  // duration + duration = duration
  template <class Rep1, class Period1, class Rep2, class Period2>
  constexpr typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type
    operator+(const duration<Rep1, Period1>& lhs,
              const duration<Rep2, Period2>& rhs);      // (1)

  // time_point + duration = time_point
  template <class Clock, class Duration1, class Rep2, class Period2>
  time_point<Clock, typename common_type<Duration1, duration<Rep2, Period2>>::type>
    operator+(const time_point<Clock, Duration1>& lhs,
              const duration<Rep2, Period2>& rhs);      // (2) C++11

  // time_point + duration = time_point
  template <class Clock, class Duration1, class Rep2, class Period2>
  constexpr time_point<Clock, typename common_type<Duration1, duration<Rep2, Period2>>::type>
    operator+(const time_point<Clock, Duration1>& lhs,
              const duration<Rep2, Period2>& rhs);      // (2) C++14

  // duration + time_point = time_point
  template <class Rep1, class Period1, class Clock, class Duration2>
  time_point<Clock, typename common_type<duration<Rep1, Period1>, Duration2>::type>
    operator+(const duration<Rep1, Period1>& lhs,
              const time_point<Clock, Duration2>& rhs); // (3) C++11

  // duration + time_point = time_point
  template <class Rep1, class Period1, class Clock, class Duration2>
  time_point<Clock, typename common_type<duration<Rep1, Period1>, Duration2>::type>
    operator+(const duration<Rep1, Period1>& lhs,
              const time_point<Clock, Duration2>& rhs); // (3) C++14
}}

• duration[link duration.md]
• time_point[link time_point.md]
• common_type[link /reference/type_traits/common_type.md]

概要

duration, time_pointの加算を行う

戻り値

• (1)

using cd = common_type<decltype(lhs), decltype(rhs)>;
return cd(cd(lhs).count() + cd(rhs).count());

• common_type[link /reference/type_traits/common_type.md]
• count()[link duration/count.md]

• (2)

using ct = time_point<Clock, common_type<decltype(lhs), decltype(rhs)>>;
return ct(lhs) += rhs;

• time_point[link time_point.md]
• common_type[link /reference/type_traits/common_type.md]

• (3)

return rhs + lhs;

例

#include <iostream>
#include <chrono>

using namespace std::chrono;

int main()
{
  // duration同士の演算
  {
    seconds s = seconds(3) + seconds(2);
    std::cout << s.count() << std::endl;

    milliseconds ms = milliseconds(3) + seconds(2);
    std::cout << ms.count() << std::endl;
  }
  std::cout << std::endl;

  // time_pointにdurationを加算
  {
    time_point<system_clock> p1 = time_point<system_clock>() + seconds(3);
    std::cout << p1.time_since_epoch().count() << std::endl;

    time_point<system_clock> p2 = seconds(3) + time_point<system_clock>();
    std::cout << p2.time_since_epoch().count() << std::endl;
  }
}

• +[color ff0000]
• seconds[link seconds.md]
• count()[link duration/count.md]
• milliseconds[link milliseconds.md]
• time_point[link time_point.md]
• system_clock[link system_clock.md]
• time_since_epoch()[link time_point/time_since_epoch.md]

出力

5
2003

3000000
3000000

バージョン

言語

• C++11

処理系

• GCC, C++11 mode: 4.6.1
• Visual C++: 2012, 2013, 2015

参照

• N3469 Constexpr Library Additions: chrono, v3