通过引用将thrust :: device_vector传递给函数

Question

我正试图通过device_vector结构

struct point 
{
    unsigned int x;
    unsigned int y;
}

以下列方式执行某项功能:

void print(thrust::device_vector<point> &points, unsigned int index)
{
    std::cout << points[index].y << points[index].y << std::endl;
}

myvector已正确初始化

print(myvector, 0);

我收到以下错误:

error: class "thrust::device_reference<point>" has no member "x"
error: class "thrust::device_reference<point>" has no member "y"

它出什么问题了？

Answer 1

不幸的是,device_reference<T>不能公开成员T,但它可以转换为T.

要实现print,请通过将每个元素转换为临时元素来生成每个元素的临时副本temp:

void print(thrust::device_vector<point> &points, unsigned int index)
{
    point temp = points[index];
    std::cout << temp.y << temp.y << std::endl;
}

每次调用时print,都会导致从GPU传输到系统内存以创建临时存储.如果你需要points一次打印整个集合,一个更有效的方法是将整个矢量points集体复制到一个host_vector或std::vector(使用thrust::copy),然后像往常一样遍历集合.