Function create_swapchain_khr 

pub unsafe fn create_swapchain_khr(
    device: VkDevice,
    create_info: *const VkSwapchainCreateInfoKHR,
    allocator: *const VkAllocationCallbacks,
    swapchain_out: *mut VkSwapchainKHR,
) -> VkResult

Safety

direct calling ffi functions.