C string literals can't just use a trivial conversion from regular string or byte literals

[dead-claudia]

Initial comment

In the "Rationale and alternatives" section of RFC 3348, it mentions a hypothetical FromStringLiteral. While I like the idea, it couldn't be as simple as a From<&'static str>/TryFrom<&'static str>: error messages would need at least a character offset + string message to be more useful than just "hey, this string contains a problem character". Also, &CStrs are really more like byte string literals, and that offset would have to be a byte offset, not a char offset, too.

This probably could justify the existence of such a trait, though. C string literals in particular wouldn't push the boundaries much, but I could see other things like regular expressions benefitting a ton from it.

[dead-claudia]

@rustbot label +F-c_str_literal +T-lang

[tgross35]

Would you mind updating the title to something that describes the desired action/behavior? It doesn't make much sense to be describing a problem with behavior if that behavior doesn't exist at all 🙂

And if #105723 is stabilized and closed, this will be the only place tracking that idea

[dead-claudia]

@tgross35 I was just calling out a specific caveat with one of the ideas in the C string literal's RFC, specifically with the FromStringLiteral idea.

If there's no FromStringLiteral, there's no issue here.