`from_str_radix` hex "+" pitfall

[Rudxain]

Description

This seems like a common mistake. It consists on using code like this:

u8::from_str_radix(hex_slice, 16)

to decode a hexadecimal string into an integer, unintentionally (in most cases) allowing + as a valid prefix for hex sequences. I say "unintentional" because hex-strs typically represent arbitrary data, not numbers/numerals.

[!note] Prev paragraph was edited for clarity

IDK if there's an existing lint-rule where this should be included, or if it warrants a new lint, that's why I've opened a blank issue

Version

Additional Labels

@rustbot label +C-enhancement

[profetia]

Isn't from_str_radix already return a Result?

[Jarcho]

from_str_radix(x, 16) allows strings like +0 which is probably not what people are expecting going by that github search.