op_precision.md

operator precision

• chrono[meta header]
• std::chrono[meta namespace]
• hh_mm_ss[meta class]
• function[meta id-type]
• cpp20[meta cpp]

constexpr explicit operator precision() const noexcept; // (1) C++20

概要

時:分:秒、秒未満をもつdurationオブジェクトに明示的に変換する。

戻り値

return to_duration();

• to_duration()[link to_duration.md]

例

#include <cassert>
#include <chrono>

namespace chrono = std::chrono;
using namespace std::chrono_literals;

int main()
{
  chrono::hh_mm_ss time1{15h + 30min + 20s};
  assert(chrono::seconds{time1} == 15h + 30min + 20s);

  chrono::hh_mm_ss time2{-(15h + 30min + 20s)};
  assert(chrono::seconds{time2} == -(15h + 30min + 20s));

  chrono::hh_mm_ss time3{15h + 30min + 20s + 123ms};
  assert(chrono::milliseconds{time3} == 15h + 30min + 20s + 123ms);
}

• 15h[link /reference/chrono/duration/op_h.md]
• 30min[link /reference/chrono/duration/op_min.md]
• 20s[link /reference/chrono/duration/op_s.md]
• 123ms[link /reference/chrono/duration/op_ms.md]

出力

バージョン

言語

• C++20

処理系

• Clang: 10.0 [mark verified]
• GCC: 11.1 [mark verified]
• Visual C++: 2019 Update 3 [mark noimpl]