pub unsafe extern "C" fn SSL_CTX_set_next_proto_select_cb( s: *mut ssl_ctx_st, cb: Option<unsafe extern "C" fn(_: *mut ssl_st, _: *mut *mut u8, _: *mut u8, _: *const u8, _: u32, _: *mut c_void) -> i32>, arg: *mut c_void, )