{

cl_uint n = 0;

cl_int err = ::clGetPlatformIDs(0, NULL, &n);

OCLM_THROW_IF_EXCEPTION(err, "clGetPlatformIDs");

std::vector<cl_platform_id> platform_ids(n);

err = ::clGetPlatformIDs(n, &platform_ids[0], NULL);

OCLM_THROW_IF_EXCEPTION(err, "clGetPlatformIDs");

platforms.resize(n);

std::copy(platform_ids.begin(), platform_ids.end(), platforms.begin());

default_platform = platforms[0];

default_device = default_platform.devices[0];