将GPU内存分配给类的成员变量的正确方法是什么?

基本上我希望为类分配GPU内存 Image 的成员变量 frame 具有 cudaMallocManaged :

class Image {
public:
    Color* frame;
};

但通过以下代码,我得到了 CUDA error = 1 为指针分配时 框架 :

#include <iostream>

// limited version of checkCudaErrors from helper_cuda.h in CUDA examples
#define checkCudaErrors(val) check_cuda((val), #val, __FILE__, __LINE__)

void check_cuda(cudaError_t result, char const* const func, const char* const file,
                int const line) {
    if (result) {
        std::cerr << "CUDA error = " << static_cast<unsigned int>(result) << " at " << file << ":"
                << line << " '" << func << "' \n";
        // Make sure we call CUDA Device Reset before exiting
        cudaDeviceReset();
        exit(-1);
    }
}

class Color {
public:
    double r, g, b;

    __host__ __device__ Color() : r(0.0), g(0.0), b(0.0) {
    }
};


class Image {
public:
    Color* frame;
};

int main() {
    int width = 1960;
    int height = 1080;

    Image *image;
    checkCudaErrors(cudaMallocManaged((void **)&image, sizeof(Image)));
    checkCudaErrors(cudaMallocManaged((void **)&(image->frame), sizeof(Color) * width, height));

    return 0;
}

将GPU内存分配给该成员变量的正确方法是什么?