pub fn from_utf8_slice_opt<'a>(v: &'a [u8]) -> Option<&'a str>
Converts a vector to a string slice without performing any allocations.
Returns None if the slice is not utf-8.
Prefix searches with a type followed by a colon (e.g.
fn:) to restrict the search to a given type.
Accepted types are: fn, mod,
struct (or str), enum,
trait, typedef (or
tdef).