Macro doe::impl_drop

macro_rules! impl_drop {
    ($struct_name:ident, $($key:ident),*) => { ... };
}

implmemt Drop for Struct

fn main() {
   use std::sync::{Arc, Mutex};
   use doe::*;
   struct Doe{
       pub name:String,
       pub nickname: Box<str>,
       key:Arc<Mutex<usize>>
   }
   impl_default!(Doe,name,nickname,key);
   impl_debug!(Doe,name,nickname,key);
   impl_drop!(Doe,name,nickname,key);
   let d = Doe::default();
   println!("{:?}",d);
}