c++ - 使用 std::bind 将函数传递给函数

Question

过去两天我一直在研究这些功能，使用 boost 后我的 CPU 和 Wall times 终于可以工作了，

最后一根刺让我无法回头，我正在尝试将一个带有参数的函数传递给另一个函数，该函数使用 std::bind 返回一个值，

我是一名学生，这对我来说是全新的，边学边学，

int CA1::binarySearch(vector<int> v, int target)
{

    int top, bottom, middle;
    top = vecSize - 1;
    bottom = 0;

    while (bottom <= top)
    {
        middle = (top + bottom) / 2;
        if (v[middle] == target)
            return  middle;
        else if (v[middle] > target)
            top = middle - 1;
        else
            bottom = middle + 1;
    }
    return -1;
}


double CA1::measure(std::function<void()> function) {
    auto startCpu = boost::chrono::process_real_cpu_clock::now();
    auto startWall = boost::chrono::process_system_cpu_clock::now();

    function();

    auto durationCpu = boost::chrono::duration_cast<boost::chrono::nanoseconds>
        (boost::chrono::process_real_cpu_clock::now() - startCpu);
    auto durationWall = boost::chrono::duration_cast<boost::chrono::nanoseconds>
        (boost::chrono::process_system_cpu_clock::now() - startWall);


    double cpuTime = static_cast<double>(durationCpu.count()) * 0.000001;
    double wallTime = static_cast<double>(durationWall.count()) * 0.000001;

    /*return static_cast<double>(duration.count()) * 0.000001;*/

    cout << "Cpu time " << cpuTime << endl;
    cout << "Wall time " << wallTime << endl;

    return cpuTime;
}

void CA1::DoTests() {

    auto  time = measure(std::bind(binarySearch, vectorUnordered, 2));
}

我得到的错误是:

error C3867: 'CA1::binarySearch': function call missing argument list; use '&CA1::binarySearch' to create a pointer to member

但根据我所阅读的内容和其他用户看到的代码片段，我在 DoTests() 中的代码是正确的。

Answer 1

类函数有明确的'this'参数，需要作为第一个参数传入:

measure(std::bind(&CA1::binarySearch, this, vectorUnordered, 2))