typically works fine (or worse, works fine in debug mode and causes unpredictable UB-related bugs in release mode).
std::mem::transmute here is a no-op at runtime; all it does is subvert the static type checker.
The difference between statically-typed languages and things like Python with type hints is _not_ that the former has any runtime type checking; it’s that subverting the (static!) type system is more difficult and requires more obvious ceremony, and that static type checking is required whereas with Python it’s optional.
If you hacked rustc to disable static typechecking you would get a similar experience to Python with type hints but without any mypy-like tools. (Of course, this would be hard to do in practice, because Rust, like most statically-typed languages, uses types not just for typechecking but also for code generation and method dispatch.)
E.g. this kind of code: https://play.rust-lang.org/?version=stable&mode=debug&editio...
typically works fine (or worse, works fine in debug mode and causes unpredictable UB-related bugs in release mode).
std::mem::transmute here is a no-op at runtime; all it does is subvert the static type checker.
The difference between statically-typed languages and things like Python with type hints is _not_ that the former has any runtime type checking; it’s that subverting the (static!) type system is more difficult and requires more obvious ceremony, and that static type checking is required whereas with Python it’s optional.
If you hacked rustc to disable static typechecking you would get a similar experience to Python with type hints but without any mypy-like tools. (Of course, this would be hard to do in practice, because Rust, like most statically-typed languages, uses types not just for typechecking but also for code generation and method dispatch.)