Macro impl_option 

macro_rules! impl_option {
    ($struct_type:ident, $struct_name:ident, copy = false, clone = false, [$($derive:meta),* ]) => { ... };
    ($struct_type:ident, $struct_name:ident, copy = false, [$($derive:meta),* ]) => { ... };
    ($struct_type:ident, $struct_name:ident, [$($derive:meta),* ]) => { ... };
}