show gpu devices with CUDA C++

test.cpp

// from https://github.com/FBerendsen/niftireg/blob/fc526c152fd5eaced271d1d6de7c16661b2abd3e/reg-lib/cuda/checkCudaCard.cpp
//
// rm test
// g++ -I/usr/local/cuda/include -L/usr/local/cuda/lib64 -lcuda test.cpp # undefined reference to cudaGetDeviceCount
// PATH=$PATH:/usr/local/cuda/bin/
// nvcc -x cu test.cpp --std=c++11 -lineinfo -o test


#include <cuda_runtime.h>
//#include <cuda.h>
//#include <stdio.h>
#include <iostream>

int main() {

    int deviceCount = 0;
    cudaGetDeviceCount(&deviceCount);
    std::cout<<"Devices: "<<deviceCount<<std::endl;
    return 1;
}