Macro agnes::field_map_fn_impl

macro_rules! field_map_fn_impl {
    (fn [$dtype1:tt](self, $field:ident) { $($body:tt)* } $($rest:tt)*) => { ... };
    (fn [$dtype1:tt, $dtype2:tt](self, $field:ident) { $($body:tt)* } $($rest:tt)*) => { ... };
    (fn [$dtype1:tt, $dtype2:tt, $dtype3:tt](self, $field:ident) { $($body:tt)* } $($rest:tt)*) => { ... };
    (fn [$dtype1:tt, $dtype2:tt, $dtype3:tt, $dtype4:tt](self, $field:ident)
            { $($body:tt)* } $($rest:tt)*) => { ... };
    (fn [$dtype1:tt, $dtype2:tt, $dtype3:tt, $dtype4:tt, $dtype5:tt](self, $field:ident)
            { $($body:tt)* }) => { ... };
    (fn all(self, $field:ident) { $($body:tt)* }) => { ... };
    (fn unsigned(self, $field:ident) { $($body:tt)* } $($rest:tt)*) => { ... };
    (fn signed(self, $field:ident) { $($body:tt)* } $($rest:tt)*) => { ... };
    (fn text(self, $field:ident) { $($body:tt)* } $($rest:tt)*) => { ... };
    (fn boolean(self, $field:ident) { $($body:tt)* } $($rest:tt)*) => { ... };
    (fn float(self, $field:ident) { $($body:tt)* } $($rest:tt)*) => { ... };
    () => { ... };
}