r">h</span></code> and <code class="computeroutput"><span class="identifier">v</span></code> are guaranteed to end no earlier
                  than after the <code class="computeroutput"><span class="identifier">W</span></code>
                  is destroyed. The writer shall not access the contents of <code class="computeroutput"><span class="identifier">h</span></code> or <code class="computeroutput"><span class="identifier">v</span></code>
                  before the first call to <code class="computer