pub unsafe extern "system" fn clCreateContext(
properties: *const cl_context_properties,
num_devices: cl_uint,
devices: *const cl_device_id,
pfn_notify: Option<extern "C" fn(*const c_char, *const c_void, size_t, *mut c_void)>,
user_data: *mut c_void,
errcode_ret: *mut cl_int,
) -> cl_context