// UTF-8-encoded rune as a token. The sequence of runes returned is
// equivalent to that from a range loop over the input as a string, which
// means that erroneous UTF-8 encodings translate to U+FFFD = "\xef\xbf\xbd".
// Because of the Scan interface, this makes it impossible for the client to
// distinguish correctly encoded replacement runes from encoding errors.
func ScanRunes(data []byte, atEOF bool) (advance int, token []byte, err error) {

the range of valid Unicode code points are converted to <code>"\uFFFD"</code>.

<pre>
string('a')       // "a"
string(-1)        // "\ufffd" == "\xef\xbf\xbd"
string(0xf8)      // "\u00f8" == "ø" == "\xc3\xb8"
type MyString string
MyString(0x65e5)  // "\u65e5" == "日" == "\xe6\x97\xa5"
</pre>
</li>

<li>
Converting a slice of bytes to a string type yields

  </mime-type>
  <mime-type type="application/vnd.fujixerox.docuworks">
    <glob pattern="*.xdw"/>
  </mime-type>
  <mime-type type="application/vnd.fujixerox.docuworks.binder">
    <glob pattern="*.xbd"/>
  </mime-type>
  <mime-type type="application/vnd.fut-misnet"/>
  <mime-type type="application/vnd.fuzzysheet">
    <glob pattern="*.fzs"/>
  </mime-type>
  <mime-type type="application/vnd.genomatix.tuxedo">

<pre>
string('a')          // "a"
string(65)           // "A"
string('\xf8')       // "\u00f8" == "ø" == "\xc3\xb8"
string(-1)           // "\ufffd" == "\xef\xbf\xbd"

type myString string
myString('\u65e5')   // "\u65e5" == "日" == "\xe6\x97\xa5"
</pre>

Note: This form of conversion may eventually be removed from the language.