Blog Post: Beating std::visit Without Really Trying

[SrMordred]

I wonder about the generated Assembly:
In Rust if u add #[repr(usize)] to the enum the generated code as 
only two lines.


In D, Look like the first assembly lines are checking for 
errors(or out of bounds index?).
But why if this is a final switch? (also assert(0); at the end 
don´t help )