String/str are both valid UTF-8 by definition, though. Plain ol' piles of bytes in Rust are generally represented by Vec<u8>/[u8]. Rust could have done better

String/str are both valid UTF-8 by definition, though. Plain ol' piles of bytes in Rust are generally represented by Vec<u8>/[u8]. Rust could have done better in naming, but a definite design goal of the language (for better and worse) is to not make things that are complicated for the compiler appear simple to the user. Which unfortunately results in: String/str CString/CStr OsString/OsStr Vec<u8>/[u8] AsRef<str> Cow<`a, str>