zlacker

> This is, of course, exactly what Rust does: I am not aware of a single thing that &str allows you to do that you cannot do with &[u8], except things that do require you to assume it's valid UTF-8.

Doesn't this demonstrate my point? If you can do everything with &[u8], what's the point in validating UTF-8? It's just a less universal string type, and your program wastes CPU cycles doing unnecessary validation.

>>maxdam+(OP)
> except things that do require you to assume it's valid UTF-8

That's the point.

>>matt_k+j41
But no one has demonstrated an actual operation that requires valid UTF-8. The reasoning is always circular: "I require valid UTF-8 because someone else requires valid UTF-8".

Eventually there should be an underlying operation which can only work on valid UTF-8, but that doesn't exist. UTF-8 was designed such that invalid data can be detected and handled, without affecting the meaning of valid subsequences in the same string.

>>maxdam+zs1
> UTF-8 was designed such that invalid data can be detected and handled, without affecting the meaning of valid subsequences in the same string.

But there is not a canonical response to invalid data. So literally every operation that might need to make a choice of what to do when presented what invalid data should either (a) accept a parameter asking what to do on error and potentially fail or (b) take a parameter type that forces errors to be handled in advance.