C++程序  |  27行  |  710 B

//===----------------------------------------------------------------------===//
//
//                     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>

// time_point

// time_point& operator-=(const duration& d);

#include <chrono>
#include <cassert>

int main()
{
    typedef std::chrono::system_clock Clock;
    typedef std::chrono::milliseconds Duration;
    std::chrono::time_point<Clock, Duration> t(Duration(3));
    t -= Duration(2);
    assert(t.time_since_epoch() == Duration(1));
}