pub type PFN_CERT_STORE_PROV_CLOSE = Option<unsafe extern "C" fn(hStoreProv: HCERTSTOREPROV, dwFlags: DWORD)>;
enum PFN_CERT_STORE_PROV_CLOSE { None, Some(unsafe extern "C" fn(_: *mut c_void, _: u32)), }
No value.
Some value of type T.
T