lense::lense_struct!

macro_rules! lense_struct {
    (pub $lense:ident: $($name:ident: $ty:ty),* $(,)*) => { ... };
    ($lense:ident: $($name:ident: $ty:ty),* $(,)*) => { ... };
    (PUB struct $lense:ident: $($name:ident: $ty:ty),*) => { ... };
    (PRIV struct $lense:ident: $($name:ident: $ty:ty),*) => { ... };
    ($vis:ident $lense:ident: $($struct_item_name:ident: $struct_item_type:ty),*) => { ... };
}