pub type PFN_vkGetFenceStatus = Option<unsafe extern "C" fn(device: VkDevice, fence: VkFence) -> VkResult>;
enum PFN_vkGetFenceStatus { None, Some(unsafe extern "C" fn(_: *mut VkDevice_T, _: *mut VkFence_T) -> i32), }
No value.
Some value of type T.
T