various documentation fixes

This commit is contained in:
Andrzej Krzemienski
2014-06-20 16:25:57 +02:00
parent 4cbb67e505
commit 599c75a6d3
7 changed files with 211 additions and 222 deletions

View File

@ -902,40 +902,52 @@
</p></blockquote></div>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<span class="bold"><strong>Effect:</strong></span> Move-assigns another <code class="computeroutput"><span class="identifier">optional</span></code> to an <code class="computeroutput"><span class="identifier">optional</span></code>.
<span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code>
is <code class="computeroutput"><span class="identifier">MoveConstructible</span></code>
and <code class="computeroutput"><span class="identifier">MoveAssignable</span></code>.
</li>
<li class="listitem">
<span class="bold"><strong>Postconditions:</strong></span> If <code class="computeroutput"><span class="identifier">rhs</span></code>
is initialized, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
is initialized and its value is moved from <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code>, <code class="computeroutput"><span class="identifier">rhs</span></code>
remains initialized; else <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is uninitialized.
<span class="bold"><strong>Effects:</strong></span>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
If <code class="computeroutput"><span class="special">!*</span><span class="keyword">this</span>
<span class="special">&amp;&amp;</span> <span class="special">!</span><span class="identifier">rhs</span></code> no effect, otherwise
</li>
<li class="listitem">
if <code class="computeroutput"><span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span>
<span class="special">&amp;&amp;</span> <span class="special">!</span><span class="identifier">rhs</span></code>, destroys the contained value
by calling <code class="computeroutput"><span class="identifier">val</span><span class="special">-&gt;</span><span class="identifier">T</span><span class="special">::~</span><span class="identifier">T</span><span class="special">()</span></code>, otherwise
</li>
<li class="listitem">
if <code class="computeroutput"><span class="special">!*</span><span class="keyword">this</span>
<span class="special">&amp;&amp;</span> <span class="keyword">bool</span><span class="special">(</span><span class="identifier">rhs</span><span class="special">)</span></code>, initializes the contained value
as if direct-initializing an object of type <code class="computeroutput"><span class="identifier">T</span></code>
with <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(*</span><span class="identifier">rhs</span><span class="special">)</span></code>,
otherwise
</li>
<li class="listitem">
(if <code class="computeroutput"><span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span>
<span class="special">&amp;&amp;</span> <span class="keyword">bool</span><span class="special">(</span><span class="identifier">rhs</span><span class="special">)</span></code>) assigns <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(*</span><span class="identifier">rhs</span><span class="special">)</span></code> to the contained value.
</li>
</ul></div>
</li>
<li class="listitem">
<span class="bold"><strong>Throws:</strong></span> Whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="keyword">operator</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&amp;&amp;</span> <span class="special">)</span></code>
or <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span> <span class="special">&amp;&amp;</span>
<span class="special">)</span></code> throws.
<span class="bold"><strong>Postconditions:</strong></span> <code class="computeroutput"><span class="keyword">bool</span><span class="special">(</span><span class="identifier">rhs</span><span class="special">)</span> <span class="special">==</span> <span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span></code>.
</li>
<li class="listitem">
<span class="bold"><strong>Remarks:</strong></span> The expression inside <code class="computeroutput"><span class="keyword">noexcept</span></code> is equivalent to <code class="computeroutput"><span class="identifier">is_nothrow_move_constructible</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;::</span><span class="identifier">value</span> <span class="special">&amp;&amp;</span>
<span class="identifier">is_nothrow_move_assignable</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;::</span><span class="identifier">value</span></code>.
</li>
<li class="listitem">
<span class="bold"><strong>Notes:</strong></span> If both <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> and <code class="computeroutput"><span class="identifier">rhs</span></code>
are initially initialized, <code class="computeroutput"><span class="identifier">T</span></code>'s
<span class="emphasis"><em>move assignment operator</em></span> is used. If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
is initially initialized but <code class="computeroutput"><span class="identifier">rhs</span></code>
is uninitialized, <code class="computeroutput"><span class="identifier">T</span></code>'s
[destructor] is called. If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initially uninitialized but <code class="computeroutput"><span class="identifier">rhs</span></code> is initialized, <code class="computeroutput"><span class="identifier">T</span></code>'s
<span class="emphasis"><em>move constructor</em></span> is called.
</li>
<li class="listitem">
<span class="bold"><strong>Exception Safety:</strong></span> In the event of an
exception, the initialization state of <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is unchanged and its value unspecified
as far as optional is concerned (it is up to <code class="computeroutput"><span class="identifier">T</span></code>'s
<code class="computeroutput"><span class="keyword">operator</span><span class="special">=()</span></code>).
If <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
is initially uninitialized and <code class="computeroutput"><span class="identifier">T</span></code>'s
<span class="emphasis"><em>move constructor</em></span> fails, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is left properly uninitialized.
<span class="bold"><strong>Exception Safety:</strong></span> If any exception is
thrown, the initialization state of <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> and <code class="computeroutput"><span class="identifier">rhs</span></code>
remain unchanged. If an exception is thrown during the call to <code class="computeroutput"><span class="identifier">T</span></code>'s move constructor, the state of
<code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code>
is determined by the exception safety guarantee of <code class="computeroutput"><span class="identifier">T</span></code>'s
move constructor. If an exception is thrown during the call to T's move-assignment,
the state of <code class="computeroutput"><span class="special">**</span><span class="keyword">this</span></code>
and <code class="computeroutput"><span class="special">*</span><span class="identifier">rhs</span></code>
is determined by the exception safety guarantee of T's move assignment.
</li>
<li class="listitem">
<span class="bold"><strong>Example:</strong></span>
@ -1064,6 +1076,8 @@
<span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">U</span><span class="special">&gt;</span> <span class="identifier">opt1</span><span class="special">;</span>
<span class="identifier">opt1</span> <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(</span><span class="identifier">opt0</span><span class="special">)</span> <span class="special">;</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">opt0</span> <span class="special">);</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">opt1</span> <span class="special">)</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="special">*</span><span class="identifier">opt1</span> <span class="special">==</span> <span class="keyword">static_cast</span><span class="special">&lt;</span><span class="identifier">U</span><span class="special">&gt;(</span><span class="identifier">v</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span>
</pre>
</li>
@ -1823,7 +1837,7 @@
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code>
shall meet requirements of <code class="computeroutput"><span class="identifier">EqualityComparable</span></code>.
shall meet requirements of <a href="http://www.sgi.com/tech/stl/EqualityComparable.html" target="_top"><code class="computeroutput"><span class="identifier">EqualityComparable</span></code></a>.
</li>
<li class="listitem">
<span class="bold"><strong>Returns:</strong></span> If both <code class="computeroutput"><span class="identifier">x</span></code>
@ -1833,41 +1847,28 @@
If only <code class="computeroutput"><span class="identifier">x</span></code> or <code class="computeroutput"><span class="identifier">y</span></code> is initialized, <code class="computeroutput"><span class="keyword">false</span></code>.
If both are uninitialized, <code class="computeroutput"><span class="keyword">true</span></code>.
</li>
<li class="listitem">
<span class="bold"><strong>Throws:</strong></span> Nothing.
</li>
<li class="listitem">
<span class="bold"><strong>Notes:</strong></span> Pointers have shallow relational
operators while <code class="computeroutput"><span class="identifier">optional</span></code>
has deep relational operators. Do not use <code class="computeroutput"><span class="keyword">operator</span>
<span class="special">==</span></code> directly in generic code which
expect to be given either an <code class="computeroutput"><span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span></code> or a pointer; use <a href="../../../../../utility/OptionalPointee.html#equal" target="_top"><code class="computeroutput"><span class="identifier">equal_pointees</span><span class="special">()</span></code></a>
has deep relational operators. Do not use <code class="computeroutput"><span class="keyword">operator</span><span class="special">==</span></code> directly in generic code which expect
to be given either an <code class="computeroutput"><span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span></code> or a pointer; use <a href="../../../../../utility/OptionalPointee.html#equal" target="_top"><code class="computeroutput"><span class="identifier">equal_pointees</span><span class="special">()</span></code></a>
instead
</li>
<li class="listitem">
<span class="bold"><strong>Example:</strong></span>
<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">x</span><span class="special">(</span><span class="number">12</span><span class="special">);</span>
<span class="identifier">T</span> <span class="identifier">y</span><span class="special">(</span><span class="number">12</span><span class="special">);</span>
<span class="identifier">T</span> <span class="identifier">z</span><span class="special">(</span><span class="number">21</span><span class="special">);</span>
<span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="identifier">def0</span> <span class="special">;</span>
<span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="identifier">def1</span> <span class="special">;</span>
<span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="identifier">optX</span><span class="special">(</span><span class="identifier">x</span><span class="special">);</span>
<span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="identifier">optY</span><span class="special">(</span><span class="identifier">y</span><span class="special">);</span>
<span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="identifier">optZ</span><span class="special">(</span><span class="identifier">z</span><span class="special">);</span>
<pre class="programlisting"><span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="identifier">oN</span><span class="special">,</span> <span class="identifier">oN_</span><span class="special">;</span>
<span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="identifier">o1</span><span class="special">(</span><span class="identifier">T</span><span class="special">(</span><span class="number">1</span><span class="special">)),</span> <span class="identifier">o1_</span><span class="special">(</span><span class="identifier">T</span><span class="special">(</span><span class="number">1</span><span class="special">));</span>
<span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="identifier">o2</span><span class="special">(</span><span class="identifier">T</span><span class="special">(</span><span class="number">2</span><span class="special">));</span>
<span class="comment">// Identity always hold</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">def0</span> <span class="special">==</span> <span class="identifier">def0</span> <span class="special">);</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">optX</span> <span class="special">==</span> <span class="identifier">optX</span> <span class="special">);</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">oN</span> <span class="special">==</span> <span class="identifier">oN</span> <span class="special">);</span> <span class="comment">// Identity implies equality</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">o1</span> <span class="special">==</span> <span class="identifier">o1</span> <span class="special">);</span> <span class="comment">//</span>
<span class="comment">// Both uninitialized compare equal</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">def0</span> <span class="special">==</span> <span class="identifier">def1</span> <span class="special">);</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">oN</span> <span class="special">==</span> <span class="identifier">oN_</span> <span class="special">);</span> <span class="comment">// Both uninitialized compare equal</span>
<span class="comment">// Only one initialized compare unequal.</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">def0</span> <span class="special">!=</span> <span class="identifier">optX</span> <span class="special">);</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">oN</span> <span class="special">!=</span> <span class="identifier">o1</span> <span class="special">);</span> <span class="comment">// Initialized unequal to initialized.</span>
<span class="comment">// Both initialized compare as (*lhs == *rhs)</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">optX</span> <span class="special">==</span> <span class="identifier">optY</span> <span class="special">)</span> <span class="special">;</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">optX</span> <span class="special">!=</span> <span class="identifier">optZ</span> <span class="special">)</span> <span class="special">;</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">o1</span> <span class="special">==</span> <span class="identifier">o1_</span> <span class="special">);</span> <span class="comment">// Both initialized compare as (*lhs == *rhs)</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">o1</span> <span class="special">!=</span> <span class="identifier">o2</span> <span class="special">);</span> <span class="comment">//</span>
</pre>
</li>
</ul></div>
@ -1881,50 +1882,44 @@
</p></blockquote></div>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<span class="bold"><strong>Requires:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code>
shall meet requirements of <code class="computeroutput"><span class="identifier">LessThanComparable</span></code>.
<span class="bold"><strong>Requires:</strong></span> Expression <code class="computeroutput"><span class="special">*</span><span class="identifier">x</span> <span class="special">&lt;</span> <span class="special">*</span><span class="identifier">y</span></code>
shall be well-formed and its result shall be convertible to <code class="computeroutput"><span class="keyword">bool</span></code>.
</li>
<li class="listitem">
<span class="bold"><strong>Returns:</strong></span> If <code class="computeroutput"><span class="identifier">y</span></code>
is not initialized, <code class="computeroutput"><span class="keyword">false</span></code>.
If <code class="computeroutput"><span class="identifier">y</span></code> is initialized and
<code class="computeroutput"><span class="identifier">x</span></code> is not initialized,
<code class="computeroutput"><span class="keyword">true</span></code>. If both <code class="computeroutput"><span class="identifier">x</span></code> and <code class="computeroutput"><span class="identifier">y</span></code>
are initialized, <code class="computeroutput"><span class="special">(*</span><span class="identifier">x</span>
<span class="special">&lt;</span> <span class="special">*</span><span class="identifier">y</span><span class="special">)</span></code>.
</li>
<li class="listitem">
<span class="bold"><strong>Throws:</strong></span> Nothing.
<span class="bold"><strong>Returns:</strong></span> <code class="computeroutput"><span class="special">(!</span><span class="identifier">y</span><span class="special">)</span> <span class="special">?</span> <span class="keyword">false</span> <span class="special">:</span> <span class="special">(!</span><span class="identifier">x</span><span class="special">)</span> <span class="special">?</span> <span class="keyword">true</span>
<span class="special">:</span> <span class="special">*</span><span class="identifier">x</span> <span class="special">&lt;</span> <span class="special">*</span><span class="identifier">y</span></code>.
</li>
<li class="listitem">
<span class="bold"><strong>Notes:</strong></span> Pointers have shallow relational
operators while <code class="computeroutput"><span class="identifier">optional</span></code>
has deep relational operators. Do not use <code class="computeroutput"><span class="keyword">operator</span>
<span class="special">&lt;</span></code> directly in generic code
which expect to be given either an <code class="computeroutput"><span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span></code> or a pointer; use <a href="../../../../../utility/OptionalPointee.html#less" target="_top"><code class="computeroutput"><span class="identifier">less_pointees</span><span class="special">()</span></code></a>
instead.
has deep relational operators. Do not use <code class="computeroutput"><span class="keyword">operator</span><span class="special">&lt;</span></code> directly in generic code which expect
to be given either an <code class="computeroutput"><span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span></code> or a pointer; use <a href="../../../../../utility/OptionalPointee.html#less" target="_top"><code class="computeroutput"><span class="identifier">less_pointees</span><span class="special">()</span></code></a>
instead. <code class="computeroutput"><span class="identifier">T</span></code> need not be
<a href="http://www.sgi.com/tech/stl/LessThanComparable.html" target="_top"><code class="computeroutput"><span class="identifier">LessThanComparable</span></code></a>. Only single
<code class="computeroutput"><span class="keyword">operator</span><span class="special">&lt;</span></code>
is required. Other relational operations are defined in terms of this
one. If <code class="computeroutput"><span class="identifier">T</span></code>'s <code class="computeroutput"><span class="keyword">operator</span><span class="special">&lt;</span></code>
satisfies the axioms of <a href="http://www.sgi.com/tech/stl/LessThanComparable.html" target="_top"><code class="computeroutput"><span class="identifier">LessThanComparable</span></code></a> (transitivity,
antisymmetry and irreflexivity), <code class="computeroutput"><span class="identifier">optinal</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span></code> is <a href="http://www.sgi.com/tech/stl/LessThanComparable.html" target="_top"><code class="computeroutput"><span class="identifier">LessThanComparable</span></code></a>.
</li>
<li class="listitem">
<span class="bold"><strong>Example:</strong></span>
<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">x</span><span class="special">(</span><span class="number">12</span><span class="special">);</span>
<span class="identifier">T</span> <span class="identifier">y</span><span class="special">(</span><span class="number">34</span><span class="special">);</span>
<span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="identifier">def</span> <span class="special">;</span>
<span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="identifier">optX</span><span class="special">(</span><span class="identifier">x</span><span class="special">);</span>
<span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="identifier">optY</span><span class="special">(</span><span class="identifier">y</span><span class="special">);</span>
<pre class="programlisting"><span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="identifier">oN</span><span class="special">,</span> <span class="identifier">oN_</span><span class="special">;</span>
<span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="identifier">o0</span><span class="special">(</span><span class="identifier">T</span><span class="special">(</span><span class="number">0</span><span class="special">));</span>
<span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="identifier">o1</span><span class="special">(</span><span class="identifier">T</span><span class="special">(</span><span class="number">1</span><span class="special">));</span>
<span class="comment">// Identity always hold</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">def</span> <span class="special">&lt;</span> <span class="identifier">def</span><span class="special">)</span> <span class="special">);</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">optX</span> <span class="special">==</span> <span class="identifier">optX</span> <span class="special">);</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">oN</span> <span class="special">&lt;</span> <span class="identifier">oN</span><span class="special">)</span> <span class="special">);</span> <span class="comment">// Identity implies equivalence</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">o1</span> <span class="special">&lt;</span> <span class="identifier">o1</span><span class="special">)</span> <span class="special">);</span>
<span class="comment">// Both uninitialized compare equal</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">def0</span> <span class="special">==</span> <span class="identifier">def1</span> <span class="special">);</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">oN</span> <span class="special">&lt;</span> <span class="identifier">oN_</span><span class="special">)</span> <span class="special">);</span> <span class="comment">// Two uninitialized are equivalent</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">oN_</span> <span class="special">&lt;</span> <span class="identifier">oN</span><span class="special">)</span> <span class="special">);</span>
<span class="comment">// Only one initialized compare unequal.</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">def0</span> <span class="special">!=</span> <span class="identifier">optX</span> <span class="special">);</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">oN</span> <span class="special">&lt;</span> <span class="identifier">o0</span> <span class="special">);</span> <span class="comment">// Uninitialized is less than initialized</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">o0</span> <span class="special">&lt;</span> <span class="identifier">oN</span><span class="special">)</span> <span class="special">);</span>
<span class="comment">// Both initialized compare as (*lhs == *rhs)</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">optX</span> <span class="special">==</span> <span class="identifier">optY</span> <span class="special">)</span> <span class="special">;</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">optX</span> <span class="special">!=</span> <span class="identifier">optZ</span> <span class="special">)</span> <span class="special">;</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="identifier">o1</span> <span class="special">&lt;</span> <span class="identifier">o2</span> <span class="special">)</span> <span class="special">;</span> <span class="comment">// Two initialized compare as (*lhs &lt; *rhs)</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">o2</span> <span class="special">&lt;</span> <span class="identifier">o1</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span>
<span class="identifier">assert</span> <span class="special">(</span> <span class="special">!(</span><span class="identifier">o2</span> <span class="special">&lt;</span> <span class="identifier">o2</span><span class="special">)</span> <span class="special">)</span> <span class="special">;</span>
</pre>
</li>
</ul></div>
@ -1935,16 +1930,11 @@
<code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span>
<span class="special">!=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">y</span> <span class="special">);</span></code>
</p></blockquote></div>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">
<span class="bold"><strong>Returns: </strong></span> <code class="computeroutput"><span class="special">!(</span>
<span class="identifier">x</span> <span class="special">==</span>
<span class="identifier">y</span> <span class="special">);</span></code>
</li>
<li class="listitem">
<span class="bold"><strong>Throws:</strong></span> Nothing.
</li>
</ul></div>
</li></ul></div>
<p>
<span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span>
</p>
@ -1953,16 +1943,11 @@
<span class="special">&gt;</span> <span class="special">(</span>
<span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">y</span> <span class="special">);</span></code>
</p></blockquote></div>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">
<span class="bold"><strong>Returns: </strong></span> <code class="computeroutput"><span class="special">(</span>
<span class="identifier">y</span> <span class="special">&lt;</span>
<span class="identifier">x</span> <span class="special">);</span></code>
</li>
<li class="listitem">
<span class="bold"><strong>Throws:</strong></span> Nothing.
</li>
</ul></div>
</li></ul></div>
<p>
<span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span>
</p>
@ -1971,16 +1956,11 @@
<span class="special">&lt;=</span> <span class="special">(</span>
<span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">y</span> <span class="special">);</span></code>
</p></blockquote></div>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">
<span class="bold"><strong>Returns: </strong></span> <code class="computeroutput"><span class="special">!(</span>
<span class="identifier">y</span> <span class="special">&lt;</span>
<span class="identifier">x</span> <span class="special">);</span></code>
</li>
<li class="listitem">
<span class="bold"><strong>Throws:</strong></span> Nothing.
</li>
</ul></div>
</li></ul></div>
<p>
<span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span>
</p>
@ -1989,27 +1969,30 @@
<span class="special">&gt;=</span> <span class="special">(</span>
<span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">y</span> <span class="special">);</span></code>
</p></blockquote></div>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">
<span class="bold"><strong>Returns: </strong></span> <code class="computeroutput"><span class="special">!(</span>
<span class="identifier">x</span><span class="special">&lt;</span><span class="identifier">y</span> <span class="special">);</span></code>
</li>
<li class="listitem">
<span class="bold"><strong>Throws:</strong></span> Nothing.
</li>
</ul></div>
<span class="identifier">x</span> <span class="special">&lt;</span>
<span class="identifier">y</span> <span class="special">);</span></code>
</li></ul></div>
<p>
<span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span>
</p>
<a name="reference_operator_compare_equal_optional_none"></a><div class="blockquote"><blockquote class="blockquote"><p>
<code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span>
<span class="special">==</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">none_t</span>
<span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span></code>
</p></blockquote></div>
<div class="blockquote"><blockquote class="blockquote"><p>
<code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span>
<span class="special">==</span> <span class="special">(</span> <span class="identifier">none_t</span><span class="special">,</span> <span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">x</span> <span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span></code>
</p></blockquote></div>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<span class="bold"><strong>Returns:</strong></span> <code class="computeroutput"><span class="special">!</span><span class="identifier">x</span></code>.
</li>
<li class="listitem">
<span class="bold"><strong>Notes:</strong></span> <code class="computeroutput"><span class="identifier">T</span></code>
need not meet requirements of <code class="computeroutput"><span class="identifier">EqualityComparable</span></code>.
need not meet requirements of <a href="http://www.sgi.com/tech/stl/EqualityComparable.html" target="_top"><code class="computeroutput"><span class="identifier">EqualityComparable</span></code></a>.
</li>
</ul></div>
<p>
@ -2020,6 +2003,10 @@
<span class="special">!=</span> <span class="special">(</span> <span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">none_t</span>
<span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span></code>
</p></blockquote></div>
<div class="blockquote"><blockquote class="blockquote"><p>
<code class="computeroutput"><span class="keyword">bool</span> <span class="keyword">operator</span>
<span class="special">!=</span> <span class="special">(</span> <span class="identifier">none_t</span><span class="special">,</span> <span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">x</span> <span class="special">)</span> <span class="keyword">noexcept</span><span class="special">;</span></code>
</p></blockquote></div>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">
<span class="bold"><strong>Returns: </strong></span> <code class="computeroutput"><span class="special">!(</span>
<span class="identifier">x</span> <span class="special">==</span>
@ -2035,12 +2022,37 @@
</p></blockquote></div>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<span class="bold"><strong>Effect:</strong></span> If both <code class="computeroutput"><span class="identifier">x</span></code>
and <code class="computeroutput"><span class="identifier">y</span></code> are initialized,
calls <code class="computeroutput"><span class="identifier">swap</span><span class="special">(*</span><span class="identifier">x</span><span class="special">,*</span><span class="identifier">y</span><span class="special">)</span></code>
using <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">swap</span></code>. If only one is initialized, say
<code class="computeroutput"><span class="identifier">x</span></code>, calls: <code class="computeroutput"><span class="identifier">y</span><span class="special">.</span><span class="identifier">reset</span><span class="special">(*</span><span class="identifier">x</span><span class="special">);</span> <span class="identifier">x</span><span class="special">.</span><span class="identifier">reset</span><span class="special">();</span></code>
If none is initialized, does nothing.
<span class="bold"><strong>Requires:</strong></span> Lvalues of type <code class="computeroutput"><span class="identifier">T</span></code> shall be swappable and <code class="computeroutput"><span class="identifier">T</span></code> shall be <code class="computeroutput"><span class="identifier">MoveConstructible</span></code>.
</li>
<li class="listitem">
<span class="bold"><strong>Effects:</strong></span>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: circle; ">
<li class="listitem">
If <code class="computeroutput"><span class="special">!*</span><span class="keyword">this</span>
<span class="special">&amp;&amp;</span> <span class="special">!</span><span class="identifier">rhs</span></code>, no effect, otherwise
</li>
<li class="listitem">
if <code class="computeroutput"><span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span>
<span class="special">&amp;&amp;</span> <span class="special">!</span><span class="identifier">rhs</span></code>, initializes the contained
value of <code class="computeroutput"><span class="identifier">rhs</span></code> as
if direct-initializing an object of type <code class="computeroutput"><span class="identifier">T</span></code>
with the expression <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(*(*</span><span class="keyword">this</span><span class="special">))</span></code>, followed by <code class="computeroutput"><span class="identifier">val</span><span class="special">-&gt;</span><span class="identifier">T</span><span class="special">::~</span><span class="identifier">T</span><span class="special">()</span></code>, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> does not contain a value and
<code class="computeroutput"><span class="identifier">rhs</span></code> contains a
value, otherwise
</li>
<li class="listitem">
if <code class="computeroutput"><span class="special">!*</span><span class="keyword">this</span>
<span class="special">&amp;&amp;</span> <span class="keyword">bool</span><span class="special">(</span><span class="identifier">rhs</span><span class="special">)</span></code>, initializes the contained value
of <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code>
as if direct-initializing an object of type <code class="computeroutput"><span class="identifier">T</span></code>
with the expression <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(*</span><span class="identifier">rhs</span><span class="special">)</span></code>, followed by <code class="computeroutput"><span class="identifier">rhs</span><span class="special">.</span><span class="identifier">val</span><span class="special">-&gt;</span><span class="identifier">T</span><span class="special">::~</span><span class="identifier">T</span><span class="special">()</span></code>, <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> contains a value and <code class="computeroutput"><span class="identifier">rhs</span></code> does not contain a value,
otherwise
</li>
<li class="listitem">
(if <code class="computeroutput"><span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span>
<span class="special">&amp;&amp;</span> <span class="keyword">bool</span><span class="special">(</span><span class="identifier">rhs</span><span class="special">)</span></code>) calls <code class="computeroutput"><span class="identifier">swap</span><span class="special">(*(*</span><span class="keyword">this</span><span class="special">),</span> <span class="special">*</span><span class="identifier">rhs</span><span class="special">)</span></code>.
</li>
</ul></div>
</li>
<li class="listitem">
<span class="bold"><strong>Postconditions:</strong></span> The states of <code class="computeroutput"><span class="identifier">x</span></code> and <code class="computeroutput"><span class="identifier">y</span></code>
@ -2052,17 +2064,6 @@
throws. If only one is initialized, whatever <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span> <span class="special">(</span> <span class="identifier">T</span><span class="special">&amp;&amp;</span> <span class="special">)</span></code>
throws.
</li>
<li class="listitem">
<span class="bold"><strong>Notes:</strong></span> If both are initialized, <code class="computeroutput"><span class="identifier">swap</span><span class="special">(</span><span class="identifier">T</span><span class="special">&amp;,</span><span class="identifier">T</span><span class="special">&amp;)</span></code>
is used unqualified but with <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">swap</span></code>
introduced in scope. If only one is initialized, <code class="computeroutput"><span class="identifier">T</span><span class="special">::~</span><span class="identifier">T</span><span class="special">()</span></code> and <code class="computeroutput"><span class="identifier">T</span><span class="special">::</span><span class="identifier">T</span><span class="special">(</span> <span class="identifier">T</span><span class="special">&amp;&amp;</span> <span class="special">)</span></code>
is called.
</li>
<li class="listitem">
<span class="bold"><strong>Exception Safety:</strong></span> If both are initialized,
this operation has the exception safety guarantees of <code class="computeroutput"><span class="identifier">swap</span><span class="special">(</span><span class="identifier">T</span><span class="special">&amp;,</span><span class="identifier">T</span><span class="special">&amp;)</span></code>. If only one is initialized, it
has the same basic guarantee as <code class="computeroutput"><span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;::</span><span class="keyword">operator</span><span class="special">=</span> <span class="special">(</span> <span class="identifier">T</span><span class="special">&amp;&amp;</span> <span class="special">)</span></code>.
</li>
<li class="listitem">
<span class="bold"><strong>Example:</strong></span>
<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">x</span><span class="special">(</span><span class="number">12</span><span class="special">);</span>