std::chrono::steady_clock::now
static std::chrono::time_point<std::chrono::steady_clock> now(); | | (since C++11) |
|---|
返回表示当前时间点的时间点。
参数
%280%29
返回值
表示当前时间的时间点。
例外
noexcept规格：
noexcept
例
二次
#include <iostream>
#include <vector>
#include <numeric>
#include <chrono>
volatile int sink;
int main()
{
for (auto size = 1ull; size < 1000000000ull; size *= 100) {
// record start time
auto start = std::chrono::steady_clock::now();
// do some work
std::vector<int> v(size, 42);
sink = std::accumulate(v.begin(), v.end(), 0u); // make sure it's a side effect
// record end time
auto end = std::chrono::steady_clock::now();
std::chrono::duration<double> diff = end-start;
std::cout << "Time to fill and iterate a vector of "
<< size << " ints : " << diff.count() << " s\n";
}
}二次
可能的产出：
二次
Time to fill and iterate a vector of 1 ints : 2.43e-07 s
Time to fill and iterate a vector of 100 ints : 4.1e-07 s
Time to fill and iterate a vector of 10000 ints : 2.519e-05 s
Time to fill and iterate a vector of 1000000 ints : 0.00207669 s
Time to fill and iterate a vector of 100000000 ints : 0.423087 s二次
© cppreference.com在CreativeCommonsAttribution下授权-ShareAlike未移植许可v3.0。
本文档系腾讯云开发者社区成员共同维护，如有问题请联系 cloudcommunity@tencent.com
