std:: clock_t

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C-style date and time

実装定義の範囲と精度でプロセスの実行時間を表現できる算術型。

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clock	プログラム開始からの生のプロセッサクロック時間を返す (関数)
CLOCKS_PER_SEC	1秒あたりのプロセッサクロックティック数 (マクロ定数)
Cドキュメント for clock_t