<p>
Note that if there are no read-write or write-write data races on memory location <i>x</i>,
then any read <i>r</i> on <i>x</i> has only one possible <i>W</i>(<i>r</i>):
the single <i>w</i> that immediately precedes it in the happens before order.
</p>

<p>
More generally, it can be shown that any Go program that is data-race-free,
meaning it has no program executions with read-write or write-write data races,

	Read(p []byte) (n int, err error)
	Close() error
}

type Writer interface {
	Write(p []byte) (n int, err error)
	Close() error
}

// ReadWriter's methods are Read, Write, and Close.
type ReadWriter interface {
	Reader  // includes methods of Reader in ReadWriter's method set
	Writer  // includes methods of Writer in ReadWriter's method set
}
</pre>

<p>

	Read(p []byte) (n int, err error)
	Close() error
}

type Writer interface {
	Write(p []byte) (n int, err error)
	Close() error
}

// ReadWriter's methods are Read, Write, and Close.
type ReadWriter interface {
	Reader  // includes methods of Reader in ReadWriter's method set
	Writer  // includes methods of Writer in ReadWriter's method set
}
</pre>

<p>