and <code>P1</code> and <code>P2</code> are different because they are different
type parameters.
<code>D0[int, string]</code> and <code>struct{ x int; y string }</code> are
different because the former is an <a href="#Instantiations">instantiated</a>
defined type while the latter is a type literal
(but they are still <a href="#Assignability">assignable</a>).
</p>

<h3 id="Assignability">Assignability</h3>

// input as a sequence of space-delimited tokens.
func ExampleScanner_words() {
	// An artificial input source.
	const input = "Now is the winter of our discontent,\nMade glorious summer by this sun of York.\n"
	scanner := bufio.NewScanner(strings.NewReader(input))
	// Set the split function for the scanning operation.
	scanner.Split(bufio.ScanWords)
	// Count the words.
	count := 0
	for scanner.Scan() {

			// This is wrong and leads to an output file that mangles the
			// atime and ctime fields, which are often left unused.
			//
			// In order to continue reading tar files created by former, buggy
			// versions of Go, we skeptically parse the atime and ctime fields.
			// If we are unable to parse them and the prefix field looks like
			// an ASCII string, then we fallback on the pre-Go1.8 behavior