</p>

<ol>
	<li>The <i>universe block</i> encompasses all Go source text.</li>

	<li>Each <a href="#Packages">package</a> has a <i>package block</i> containing all
	    Go source text for that package.</li>

	<li>Each file has a <i>file block</i> containing all Go source text
	    in that file.</li>

	<li>Each <a href="#If_statements">"if"</a>,
	    <a href="#For_statements">"for"</a>, and

	pc            int64 // virtual PC; count of Progs; doesn't advance for GLOBL or DATA.
	input         []lex.Token
	inputPos      int
	pendingLabels []string // Labels to attach to next instruction.
	labels        map[string]*obj.Prog
	toPatch       []Patch
	addr          []obj.Addr
	arch          *arch.Arch
	ctxt          *obj.Link
	firstProg     *obj.Prog
	lastProg      *obj.Prog

type in <code>V</code>'s type set can be converted to each type in <code>T</code>'s
type set.
</li>
<li>
Only <code>V</code> is a type parameter and a value of each
type in <code>V</code>'s type set can be converted to <code>T</code>.
</li>
<li>
Only <code>T</code> is a type parameter and <code>x</code> can be converted to each
type in <code>T</code>'s type set.
</li>

	key := dir

	// explicit on GOOS and GOARCH as global cache will use "all" cached packages for
	// an indirect imported package. See https://github.com/golang/go/issues/21181
	// for more detail.
	tags = append(tags, context.GOOS, context.GOARCH)
	sort.Strings(tags)

	for _, tag := range tags {
		if ctags[tag] {
			key += "," + tag
			ctags[tag] = false
		}
	}
	return key
}