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Merged
akrzemi1 merged 1 commit into from
Jul 17, 2014
Merged

rvalue ref overloads do not return by value #6

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21 changes: 7 additions & 14 deletions doc/20_reference.qbk
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Expand Up @@ -73,13 +73,11 @@

T const& operator *() const& ; ``[link reference_optional_operator_asterisk __GO_TO__]``
T& operator *() & ; ``[link reference_optional_operator_asterisk __GO_TO__]``
T operator *() && ; ``[link reference_optional_operator_asterisk_move __GO_TO__]``
T operator *() const&& ; ``[link reference_optional_operator_asterisk_move __GO_TO__]``
T&& operator *() && ; ``[link reference_optional_operator_asterisk_move __GO_TO__]``

T const& value() const& ; ``[link reference_optional_value __GO_TO__]``
T& value() & ; ``[link reference_optional_value __GO_TO__]``
T value() && ; ``[link reference_optional_value_move __GO_TO__]``
T value() const&& ; ``[link reference_optional_value_move __GO_TO__]``
T&& value() && ; ``[link reference_optional_value_move __GO_TO__]``

template<class U> T value_or( U && v ) const& ; ``[link reference_optional_value_or __GO_TO__]``
template<class U> T value_or( U && v ) && ; ``[link reference_optional_value_or_move __GO_TO__]``
Expand Down Expand Up @@ -864,25 +862,22 @@ __SPACE__

[#reference_optional_operator_asterisk_move]

[: `T optional<T` ['(not a ref)]`>::operator*() &&;`]
[: `T optional<T` ['(not a ref)]`>::operator*() const&&;`]
[: `T&& optional<T` ['(not a ref)]`>::operator*() &&;`]

* [*Requires:] `*this` contains a value.
* [*Effects:] Equivalent to `return std::move(*val);`.
* [*Remarks:] If `T` is not __MOVE_CONSTRUCTIBLE__, the program is ill-formed.
* [*Notes:] The requirement is asserted via `BOOST_ASSERT()`. On GCC compiler the second overload is not present, as this compiler incorrectly implements binding of references to const prvalues. On compilers that do not support ref-qualifiers on member functions both these overloads are not present.
* [*Notes:] The requirement is asserted via `BOOST_ASSERT()`. On compilers that do not support ref-qualifiers on member functions this overload is not present.

__SPACE__

[: `T & optional<T&>::operator*() const& ;`]
[: `T & optional<T&>::operator*() & ;`]
[: `T & optional<T&>::operator*() && ;`]
[: `T & optional<T&>::operator*() const&& ;`]

* [*Requires: ] `*this` is initialized
* [*Returns:] [_The] reference contained.
* [*Throws:] Nothing.
* [*Notes:] The requirement is asserted via `BOOST_ASSERT()`. On GCC compiler the fourth overload is not present, as this compiler incorrectly implements binding of references to const prvalues. On compilers that do not support ref-qualifiers on member functions these four overloads are replaced with the classical two: a `const` and non-`const` member functions.
* [*Notes:] The requirement is asserted via `BOOST_ASSERT()`. On compilers that do not support ref-qualifiers on member functions these three overloads are replaced with the classical two: a `const` and non-`const` member functions.
* [*Example:]
``
T v ;
Expand Down Expand Up @@ -922,12 +917,10 @@ __SPACE__

[#reference_optional_value_move]

[: `T optional<T>::value() && ;`]
[: `T optional<T>::value() const&& ;`]
[: `T&& optional<T>::value() && ;`]

* [*Effects:] Equivalent to `return bool(*this) ? std::move(*val) : throw bad_optional_access();`.
* [*Remarks:] If `T` is not __MOVE_CONSTRUCTIBLE__, the program is ill-formed.
* [*Notes:] On GCC compiler the second overload is not present, as this compiler incorrectly implements binding of references to const prvalues. On compilers that do not support ref-qualifiers on member functions both these overloads are not present.
* [*Notes:] On compilers that do not support ref-qualifiers on member functions this overload is not present.

__SPACE__

Expand Down
50 changes: 11 additions & 39 deletions doc/html/boost_optional/reference/detailed_semantics.html
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Expand Up @@ -1334,12 +1334,8 @@ <h5>
<span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span>
</p>
<a name="reference_optional_operator_asterisk_move"></a><div class="blockquote"><blockquote class="blockquote"><p>
<code class="computeroutput"><span class="identifier">T</span> <span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span></code>
<span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">&gt;::</span><span class="keyword">operator</span><span class="special">*()</span> <span class="special">&amp;&amp;;</span></code>
</p></blockquote></div>
<div class="blockquote"><blockquote class="blockquote"><p>
<code class="computeroutput"><span class="identifier">T</span> <span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span></code>
<span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">&gt;::</span><span class="keyword">operator</span><span class="special">*()</span> <span class="keyword">const</span><span class="special">&amp;&amp;;</span></code>
<code class="computeroutput"><span class="identifier">T</span><span class="special">&amp;&amp;</span>
<span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span></code> <span class="emphasis"><em>(not a ref)</em></span><code class="computeroutput"><span class="special">&gt;::</span><span class="keyword">operator</span><span class="special">*()</span> <span class="special">&amp;&amp;;</span></code>
</p></blockquote></div>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
Expand All @@ -1348,18 +1344,11 @@ <h5>
<li class="listitem">
<span class="bold"><strong>Effects:</strong></span> Equivalent to <code class="computeroutput"><span class="keyword">return</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">move</span><span class="special">(*</span><span class="identifier">val</span><span class="special">);</span></code>.
</li>
<li class="listitem">
<span class="bold"><strong>Remarks:</strong></span> If <code class="computeroutput"><span class="identifier">T</span></code>
is not <code class="computeroutput"><span class="identifier">MoveConstructible</span></code>,
the program is ill-formed.
</li>
<li class="listitem">
<span class="bold"><strong>Notes:</strong></span> The requirement is asserted via
<code class="computeroutput"><span class="identifier">BOOST_ASSERT</span><span class="special">()</span></code>.
On GCC compiler the second overload is not present, as this compiler
incorrectly implements binding of references to const prvalues. On compilers
that do not support ref-qualifiers on member functions both these overloads
are not present.
On compilers that do not support ref-qualifiers on member functions this
overload is not present.
</li>
</ul></div>
<p>
Expand All @@ -1377,11 +1366,6 @@ <h5>
<code class="computeroutput"><span class="identifier">T</span> <span class="special">&amp;</span>
<span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&amp;&gt;::</span><span class="keyword">operator</span><span class="special">*()</span> <span class="special">&amp;&amp;</span> <span class="special">;</span></code>
</p></blockquote></div>
<div class="blockquote"><blockquote class="blockquote"><p>
<code class="computeroutput"><span class="identifier">T</span> <span class="special">&amp;</span>
<span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&amp;&gt;::</span><span class="keyword">operator</span><span class="special">*()</span> <span class="keyword">const</span><span class="special">&amp;&amp;</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>Requires: </strong></span> <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span></code> is initialized
Expand All @@ -1396,11 +1380,9 @@ <h5>
<li class="listitem">
<span class="bold"><strong>Notes:</strong></span> The requirement is asserted via
<code class="computeroutput"><span class="identifier">BOOST_ASSERT</span><span class="special">()</span></code>.
On GCC compiler the fourth overload is not present, as this compiler
incorrectly implements binding of references to const prvalues. On compilers
that do not support ref-qualifiers on member functions these four overloads
are replaced with the classical two: a <code class="computeroutput"><span class="keyword">const</span></code>
and non-<code class="computeroutput"><span class="keyword">const</span></code> member functions.
On compilers that do not support ref-qualifiers on member functions these
three overloads are replaced with the classical two: a <code class="computeroutput"><span class="keyword">const</span></code> and non-<code class="computeroutput"><span class="keyword">const</span></code>
member functions.
</li>
<li class="listitem">
<span class="bold"><strong>Example:</strong></span>
Expand Down Expand Up @@ -1454,27 +1436,17 @@ <h5>
<span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span>
</p>
<a name="reference_optional_value_move"></a><div class="blockquote"><blockquote class="blockquote"><p>
<code class="computeroutput"><span class="identifier">T</span> <span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;::</span><span class="identifier">value</span><span class="special">()</span> <span class="special">&amp;&amp;</span>
<span class="special">;</span></code>
</p></blockquote></div>
<div class="blockquote"><blockquote class="blockquote"><p>
<code class="computeroutput"><span class="identifier">T</span> <span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;::</span><span class="identifier">value</span><span class="special">()</span> <span class="keyword">const</span><span class="special">&amp;&amp;</span> <span class="special">;</span></code>
<code class="computeroutput"><span class="identifier">T</span><span class="special">&amp;&amp;</span>
<span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;::</span><span class="identifier">value</span><span class="special">()</span> <span class="special">&amp;&amp;</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>Effects:</strong></span> Equivalent to <code class="computeroutput"><span class="keyword">return</span> <span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</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">val</span><span class="special">)</span> <span class="special">:</span> <span class="keyword">throw</span>
<span class="identifier">bad_optional_access</span><span class="special">();</span></code>.
</li>
<li class="listitem">
<span class="bold"><strong>Remarks:</strong></span> If <code class="computeroutput"><span class="identifier">T</span></code>
is not <code class="computeroutput"><span class="identifier">MoveConstructible</span></code>,
the program is ill-formed.
</li>
<li class="listitem">
<span class="bold"><strong>Notes:</strong></span> On GCC compiler the second overload
is not present, as this compiler incorrectly implements binding of references
to const prvalues. On compilers that do not support ref-qualifiers on
member functions both these overloads are not present.
<span class="bold"><strong>Notes:</strong></span> On compilers that do not support
ref-qualifiers on member functions this overload is not present.
</li>
</ul></div>
<p>
Expand Down
2 changes: 1 addition & 1 deletion doc/html/index.html
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Expand Up @@ -133,7 +133,7 @@ <h4>
</div>
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"><p><small>Last revised: June 27, 2014 at 22:17:04 GMT</small></p></td>
<td align="left"><p><small>Last revised: July 10, 2014 at 11:41:49 GMT</small></p></td>
<td align="right"><div class="copyright-footer"></div></td>
</tr></table>
<hr>
Expand Down
6 changes: 2 additions & 4 deletions doc/html/optional/reference.html
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Expand Up @@ -97,13 +97,11 @@

<span class="identifier">T</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="keyword">operator</span> <span class="special">*()</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="special">;</span> <a class="link" href="../boost_optional/reference/detailed_semantics.html#reference_optional_operator_asterisk"><span class="inlinemediaobject"><img src="../images/callouts/R.png" alt="R"></span></a>
<span class="identifier">T</span><span class="special">&amp;</span> <span class="keyword">operator</span> <span class="special">*()</span> <span class="special">&amp;</span> <span class="special">;</span> <a class="link" href="../boost_optional/reference/detailed_semantics.html#reference_optional_operator_asterisk"><span class="inlinemediaobject"><img src="../images/callouts/R.png" alt="R"></span></a>
<span class="identifier">T</span> <span class="keyword">operator</span> <span class="special">*()</span> <span class="special">&amp;&amp;</span> <span class="special">;</span> <a class="link" href="../boost_optional/reference/detailed_semantics.html#reference_optional_operator_asterisk_move"><span class="inlinemediaobject"><img src="../images/callouts/R.png" alt="R"></span></a>
<span class="identifier">T</span> <span class="keyword">operator</span> <span class="special">*()</span> <span class="keyword">const</span><span class="special">&amp;&amp;</span> <span class="special">;</span> <a class="link" href="../boost_optional/reference/detailed_semantics.html#reference_optional_operator_asterisk_move"><span class="inlinemediaobject"><img src="../images/callouts/R.png" alt="R"></span></a>
<span class="identifier">T</span><span class="special">&amp;&amp;</span> <span class="keyword">operator</span> <span class="special">*()</span> <span class="special">&amp;&amp;</span> <span class="special">;</span> <a class="link" href="../boost_optional/reference/detailed_semantics.html#reference_optional_operator_asterisk_move"><span class="inlinemediaobject"><img src="../images/callouts/R.png" alt="R"></span></a>

<span class="identifier">T</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">value</span><span class="special">()</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="special">;</span> <a class="link" href="../boost_optional/reference/detailed_semantics.html#reference_optional_value"><span class="inlinemediaobject"><img src="../images/callouts/R.png" alt="R"></span></a>
<span class="identifier">T</span><span class="special">&amp;</span> <span class="identifier">value</span><span class="special">()</span> <span class="special">&amp;</span> <span class="special">;</span> <a class="link" href="../boost_optional/reference/detailed_semantics.html#reference_optional_value"><span class="inlinemediaobject"><img src="../images/callouts/R.png" alt="R"></span></a>
<span class="identifier">T</span> <span class="identifier">value</span><span class="special">()</span> <span class="special">&amp;&amp;</span> <span class="special">;</span> <a class="link" href="../boost_optional/reference/detailed_semantics.html#reference_optional_value_move"><span class="inlinemediaobject"><img src="../images/callouts/R.png" alt="R"></span></a>
<span class="identifier">T</span> <span class="identifier">value</span><span class="special">()</span> <span class="keyword">const</span><span class="special">&amp;&amp;</span> <span class="special">;</span> <a class="link" href="../boost_optional/reference/detailed_semantics.html#reference_optional_value_move"><span class="inlinemediaobject"><img src="../images/callouts/R.png" alt="R"></span></a>
<span class="identifier">T</span><span class="special">&amp;&amp;</span> <span class="identifier">value</span><span class="special">()</span> <span class="special">&amp;&amp;</span> <span class="special">;</span> <a class="link" href="../boost_optional/reference/detailed_semantics.html#reference_optional_value_move"><span class="inlinemediaobject"><img src="../images/callouts/R.png" alt="R"></span></a>

<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">U</span><span class="special">&gt;</span> <span class="identifier">T</span> <span class="identifier">value_or</span><span class="special">(</span> <span class="identifier">U</span> <span class="special">&amp;&amp;</span> <span class="identifier">v</span> <span class="special">)</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="special">;</span> <a class="link" href="../boost_optional/reference/detailed_semantics.html#reference_optional_value_or"><span class="inlinemediaobject"><img src="../images/callouts/R.png" alt="R"></span></a>
<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">U</span><span class="special">&gt;</span> <span class="identifier">T</span> <span class="identifier">value_or</span><span class="special">(</span> <span class="identifier">U</span> <span class="special">&amp;&amp;</span> <span class="identifier">v</span> <span class="special">)</span> <span class="special">&amp;&amp;</span> <span class="special">;</span> <a class="link" href="../boost_optional/reference/detailed_semantics.html#reference_optional_value_or_move"><span class="inlinemediaobject"><img src="../images/callouts/R.png" alt="R"></span></a>
Expand Down
20 changes: 4 additions & 16 deletions include/boost/optional/optional.hpp
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Expand Up @@ -1005,12 +1005,9 @@ class optional : public optional_detail::optional_base<T>
// the behaviour is UNDEFINED
// No-throw
#ifndef BOOST_NO_CXX11_REF_QUALIFIERS
reference_const_type operator *() const& { return this->get() ; }
reference_type operator *() & { return this->get() ; }
value_type operator *() && { return boost::move(this->get()) ; }
#ifdef BOOST_CLANG
value_type operator *() const&& { return boost::move(this->get()) ; }
#endif
reference_const_type operator *() const& { return this->get() ; }
reference_type operator *() & { return this->get() ; }
reference_type_of_temporary_wrapper operator *() && { return boost::move(this->get()) ; }
#else
reference_const_type operator *() const { return this->get() ; }
reference_type operator *() { return this->get() ; }
Expand All @@ -1033,22 +1030,13 @@ class optional : public optional_detail::optional_base<T>
throw_exception(bad_optional_access());
}

value_type value() &&
{
if (this->is_initialized())
return boost::move(this->get()) ;
else
throw_exception(bad_optional_access());
}
#ifdef BOOST_CLANG
value_type value() const&&
reference_type_of_temporary_wrapper value() &&
{
if (this->is_initialized())
return boost::move(this->get()) ;
else
throw_exception(bad_optional_access());
}
#endif

#else
reference_const_type value() const
Expand Down