associated_idx_type.rs

#[macro_export]
macro_rules! associated_idx_type {
    ($base_type: ty, $id_type :ident) => {
        #[derive(Clone, Copy, Debug, Default, Eq, Hash, Ord, PartialEq, PartialOrd)]
        pub struct $id_type(pub usize);

        impl ops::Index<$id_type> for Vec<$base_type> {
            type Output = $base_type;

            fn index(&self, index: $id_type) -> &$base_type {
                &self[index.0]
            }
        }

        impl<'a> ops::Index<&'a $id_type> for Vec<$base_type> {
            type Output = $base_type;

            fn index(&self, index: &$id_type) -> &$base_type {
                &self[index.0]
            }
        }

        impl<'a> ops::IndexMut<&'a $id_type> for Vec<$base_type> {
            fn index_mut(&mut self, index: &$id_type) -> &mut $base_type {
                &mut self[index.0]
            }
        }
    }
}