Macro gen_vector_wrapper_impl

macro_rules! gen_vector_wrapper_impl {
    (
        vector_type: $type : ident,
        scalar_type: $scalar_type : ty,
        primitive_type: $primitive_type : ty,
        r_prefix: $r_prefix : ident,
        SEXP: $sexp : ident,
        doc_name: $doc_name : ident,
        altrep_constructor: $altrep_constructor : ident,
    ) => { ... };
}

Generates impl block and required traits for a vector type.