mode. Otherwise, there are non-standard cgo packages involved, and cmd/link
will use external linking mode. The first rule means that a build of
the godoc binary, which uses net but no other cgo, can run without
needing gcc available. The second rule means that a build of a
cgo-wrapped library like sqlite3 can generate a standalone executable
instead of needing to refer to a dynamic library. The specific choice

	// A Buffer can turn a string or a []byte into an io.Reader.
	buf := bytes.NewBufferString("R29waGVycyBydWxlIQ==")
	dec := base64.NewDecoder(base64.StdEncoding, buf)
	io.Copy(os.Stdout, dec)
	// Output: Gophers rule!
}

func ExampleBuffer_Bytes() {
	buf := bytes.Buffer{}
	buf.Write([]byte{'h', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd'})
	os.Stdout.Write(buf.Bytes())
	// Output: hello world
}

such a symbol must be defined in a Go source file instead.
Assembly source can still refer to the symbol by name
even without <code>DATA</code> and <code>GLOBL</code> directives.
A good general rule of thumb is to define all non-<code>RODATA</code>
symbols in Go instead of in assembly.
</p>

<p>
Each function also needs annotations giving the location of

	return unicode.IsSpace(r)
}

// Title treats s as UTF-8-encoded bytes and returns a copy with all Unicode letters that begin
// words mapped to their title case.
//
// Deprecated: The rule Title uses for word boundaries does not handle Unicode
// punctuation properly. Use golang.org/x/text/cases instead.
func Title(s []byte) []byte {
	// Use a closure here to remember state.

<code>"hello, world"</code>.  (It might print the empty string,
crash, or do something else.)
</p>

<p class="rule">
The <i>k</i>th receive on a channel with capacity <i>C</i> is synchronized before the completion of the <i>k</i>+<i>C</i>th send from that channel completes.
</p>

<p>
This rule generalizes the previous rule to buffered channels.
It allows a counting semaphore to be modeled by a buffered channel: