List OpenCL devices and platforms using C++

cl_devices.cpp

#include <iostream>  
#include <CL/cl.hpp>

int main(int argc, char *argv[]) {
  std::vector<cl::Platform> platforms;
  cl::Platform::get(&platforms);

  int platform_id = 0;
  int device_id = 0;

  std::cout << "Number of Platforms: " << platforms.size() << std::endl;

  for(std::vector<cl::Platform>::iterator it = platforms.begin(); it != platforms.end(); ++it) {
    cl::Platform platform(*it);

    std::cout << "Platform ID: " << platform_id++ << std::endl;
    std::cout << "Platform Name: " << platform.getInfo<CL_PLATFORM_NAME>() << std::endl;
    std::cout << "Platform Vendor: " << platform.getInfo<CL_PLATFORM_VENDOR>() << std::endl;

    std::vector<cl::Device> devices;
    platform.getDevices(CL_DEVICE_TYPE_GPU | CL_DEVICE_TYPE_CPU, &devices);

    for(std::vector<cl::Device>::iterator it2 = devices.begin(); it2 != devices.end(); ++it2) {
      cl::Device device(*it2);

      std::cout << std::endl << "\tDevice " << device_id++ << ": " << std::endl;
      std::cout << "\t\tDevice Name: " << device.getInfo<CL_DEVICE_NAME>() << std::endl;
      std::cout << "\t\tDevice Vendor: " << device.getInfo<CL_DEVICE_VENDOR>() << std::endl;
      std::cout << "\t\tDevice Version: " << device.getInfo<CL_DEVICE_VERSION>() << std::endl;
      switch (device.getInfo<CL_DEVICE_TYPE>()) {
        case 4:
          std::cout << "\t\tDevice Type: GPU" << std::endl;
          break;
        case 2:
          std::cout << "\t\tDevice Type: CPU" << std::endl;
          break;
        default:
          std::cout << "\t\tDevice Type: unknown" << std::endl;
      }
      std::cout << "\t\tDevice Max Compute Units: " << device.getInfo<CL_DEVICE_MAX_COMPUTE_UNITS>() << std::endl;
      std::cout << "\t\tDevice Global Memory: " << device.getInfo<CL_DEVICE_GLOBAL_MEM_SIZE>() << std::endl;
      std::cout << "\t\tDevice Max Clock Frequency: " << device.getInfo<CL_DEVICE_MAX_CLOCK_FREQUENCY>() << std::endl;
      std::cout << "\t\tDevice Max Memory Allocation: " << device.getInfo<CL_DEVICE_MAX_MEM_ALLOC_SIZE>() << std::endl;
      std::cout << "\t\tDevice Local Memory: " << device.getInfo<CL_DEVICE_LOCAL_MEM_SIZE>() << std::endl;
      std::cout << "\t\tDevice Available: " << device.getInfo<CL_DEVICE_AVAILABLE>() << std::endl;
    }
    std::cout << std::endl;
  }
}

Compile with g++ opencl_devices.cpp -lOpenCL