Derive Macro rustler_codegen::NifTuple

#[derive(NifTuple)]

Implementation of a macro that lets the user annotate a struct with NifTuple so that the struct can be encoded or decoded from an Elixir map. For example, the following struct annotated as such:

#[derive(NifTuple)]
struct AddTuple {
    lhs: i32,
    rhs: i32,
}

Given the values 33 and 21 for this struct, this would result, when encoded, in an elixir tuple with two elements like:

{33, 21}

The size of the tuple will depend on the number of elements in the struct.