pub type clCommandCopyBufferKHR_fn = Option<unsafe extern "C" fn(command_buffer: cl_command_buffer_khr, command_queue: cl_command_queue, src_buffer: cl_mem, dst_buffer: cl_mem, src_offset: size_t, dst_offset: size_t, size: size_t, num_sync_points_in_wait_list: cl_uint, sync_point_wait_list: *const cl_sync_point_khr, sync_point: *mut cl_sync_point_khr, mutable_handle: *mut cl_mutable_command_khr) -> cl_int>;