#[macro_use(defer)]
 extern crate scopeguard;
 
 use scopeguard::guard;
 
f() fn f() {
     defer! {
         println!("Called at return or panic");
     }
     panic!();
 }
 
 use std::fs::File;
 use std::io::Write;
 
g() fn g() {
     let f = File::create("newfile.txt").unwrap();
     let mut file = guard(f, |f| {
         // write file at return or panic
         let _ = f.sync_all();
     });
     // access the file through the scope guard itself
     file.write_all(b"test me\n").unwrap();
 }
 
main() fn main() {
     f();
     g();
 }