Macro helix::codegen_struct

macro_rules! codegen_struct {
    { pub: false, rust_name: $rust_name:tt, ruby_name: $ruby_name:tt, struct: () } => { ... };
    { pub: true, rust_name: $rust_name:tt, ruby_name: $ruby_name:tt, struct: () } => { ... };
    { pub: false, rust_name: $rust_name:tt, ruby_name: $ruby_name:tt, struct: { $($rest:tt)* } } => { ... };
    { pub: true, rust_name: $rust_name:tt, ruby_name: $ruby_name:tt, struct: { $($rest:tt)* } } => { ... };
    {
        pub: { $($pub:tt)* },
        rust_name: $rust_name:tt,
        ruby_name: $ruby_name:tt,
        struct: { $($struct:tt)* }
    } => { ... };
}