/// it's easy to overlook the `!` in `assert!(!this_is.really_eycatching())`
#[cfg(test)]
macro_rules! assert_not {
    //direct forward + `!`
    ($($t:tt)*) => (assert!(! $($t)*));
}

#[cfg(test)]
macro_rules! assert_ok {
    ($val:expr) => ({
        match $val {
            Ok( res ) => res,
            Err( err ) => panic!( "expected Ok(..) got Err({:?})", err)
        }
    });
    ($val:expr, $ctx:expr) => ({
        match $val {
            Ok( res ) => res,
            Err( err ) => panic!( "expected Ok(..) got Err({:?}) [ctx: {:?}]", err, $ctx)
        }
    });
}

#[cfg(test)]
macro_rules! assert_err {
    ($val:expr) => ({
        match $val {
            Ok( val ) => panic!( "expected Err(..) got Ok({:?})", val),
            Err( err ) => err,
        }
    });
    ($val:expr, $ctx:expr) => ({
        match $val {
            Ok( val ) => panic!( "expected Err(..) got Ok({:?}) [ctx: {:?}]", val, $ctx),
            Err( err ) => err,
        }
    });
}




// macro_rules! deref0 {
//     (+mut $name:ident => $tp:ty) => (
//         deref0!{-mut $name => $tp }
//         impl ::std::ops::DerefMut for $name {
//             fn deref_mut( &mut self ) -> &mut Self::Target {
//                 &mut self.0
//             }
//         }
//     );
//     (-mut $name:ident => $tp:ty) => (
//         impl ::std::ops::Deref for $name {
//             type Target = $tp;
//             fn deref( &self ) -> &Self::Target {
//                 &self.0
//             }
//         }
//     );
// }