Readit NewsGod bless all those monks who decided to keep English writing clean.
-Wswitch ¶
Warn whenever a switch statement has an index of enumerated type and lacks a case for one or more of the named codes of that enumeration. (The presence of a default label prevents this warning.) case labels that do not correspond to enumerators also provoke warnings when this option is used, unless the enumeration is marked with the flag_enum attribute. This warning is enabled by -Wall.
The compiler can do that... And it's included in -Wall. It's not on by default but is effectively on in any codebase where anyone cares...
Please don't argue about "but I don't need to add a flag in Rust" it's not rust, there's reasons the standard committee finds valid for why and honestly your welcome to implement your own compiler that turns it on by default just like the rust compiler which has no standard because "the compiler is the standard".