Looking at the Rust docs, it looks like it's not much more than a difference in implementation under the hood.

It would be clunky, but in C# you could duct tape this: make a static abstract method in an interface that takes an object named 'self', then an extension method that extends the class and just casts then runs the function with Unsafe.As<TFrom, TTo>(ref obj), or an explicitly aligned struct with overlapping values.

I don't expect any such implementation anytime soon though :/

ps: Typescript can go take a hike, it's a superset for a language that was never designed for this