Comment by zanny

Rust is extremely good at this with newtype syntax and the ability to apply impls and derives to masking types.

Your JSON data might be a string, but having a Json type that guarantees its valid Json is way better. Same with stringified Base64, a constrained numeric value for a tunable, etc. Because using from impls on these types lets the compiler figure out almost all invalid type usages at compile time and give you eloquent feedback on it.