static BYTES_ARRAY: [u8; 128] = [
  0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
  39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75,
  76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109,
  110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127,
];

#[test]
pub fn test_bytes_array_values() {
  for x in 0..128 {
    assert_eq!(BYTES_ARRAY[x] as usize, x);
  }
}

/// ```rust
/// use tlhconv::*;
/// for valid_ascii_byte in 0..128 {
///   let this_char = ascii_to_static_str(valid_ascii_byte).chars().nth(0).unwrap();
///   assert_eq!(this_char, valid_ascii_byte as u8 as char);
/// }
///
/// for invalid_ascii_byte in -127..0 {
///   let this_char = ascii_to_static_str(invalid_ascii_byte).chars().nth(0).unwrap();
///   assert_eq!(this_char, '?');
/// }
/// ```
pub fn ascii_to_static_str(ascii_byte: i8) -> &'static str {
  let ascii_byte = if ascii_byte < 0 {
    63 // the '?' byte
  } else {
    ascii_byte
  };
  unsafe {
    // First, we build a &[u8]...
    let slice = ::std::slice::from_raw_parts(BYTES_ARRAY.as_ptr().offset(ascii_byte as isize), 1);
    // and then convert that slice into a string slice
    ::std::str::from_utf8_unchecked(slice)
  }
}