Method back_advance

crates/sre_engine/src/string.rs:69–73

(cursor: &mut StringCursor)

    #[inline]
    fn back_advance(cursor: &mut StringCursor) -> u32 {
        cursor.position -= 1;
        unsafe { cursor.ptr = cursor.ptr.sub(1) };
        unsafe { *cursor.ptr as u32 }
    }

    #[inline]
    fn back_peek(cursor: &StringCursor) -> u32 {