Macro embedded_builder::field_method

macro_rules! field_method {
    (r, $name: ident, $field: tt, $t:ty, $shift: expr) => { ... };
    (w, $name: ident, $field: tt, $t:ty, $shift: expr) => { ... };
    (r, $name: ident, $field: tt, $t:ty, $shift: expr, $mask: expr) => { ... };
    (w, $name: ident, $field: tt, $t:ty, $shift: expr, $mask: expr) => { ... };
}