Macro candid::Encode

macro_rules! Encode {
    ( $($x:expr),* ) => { ... };
    ( @PutValue $builder:ident $x:expr, $($tail:expr,)* ) => { ... };
    ( @PutValue $builder:ident ) => { ... };
}

Encode sequence of Rust values into Candid message of type candid::Result<Vec<u8>>.