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Andrzej Krzemienski
2014-06-16 14:26:22 +02:00
parent 04b9080612 9edf2ddac1
commit a158b85bd6
12 changed files with 132 additions and 54 deletions
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5
doc/00_optional.qbk
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@ -26,8 +26,9 @@ Distributed under the Boost Software License, Version 1.0.
[def __BOOST_TUPLE__ [@../../../tuple/index.html Boost.Tuple]]
[def __BOOST_TRIBOOL__ [@../../../../doc/html/tribool.html boost::tribool]]
[def __OPTIONAL_POINTEE__ [@../../../utility/OptionalPointee.html OptionalPointee]]
[def __COPY_CONSTRUCTIBLE__ [@../../../utility/CopyConstructible.html Copy Constructible]]
[def __OPTIONAL_POINTEE__ [@../../../utility/OptionalPointee.html `OptionalPointee`]]
[def __COPY_CONSTRUCTIBLE__ [@../../../utility/CopyConstructible.html `CopyConstructible`]]
[def __MOVE_CONSTRUCTIBLE__ `MoveConstructible`]
[def __FUNCTION_EQUAL_POINTEES__ [@../../../utility/OptionalPointee.html#equal `equal_pointees()`]]
[def __FUNCTION_LESS_POINTEES__ [@../../../utility/OptionalPointee.html#less `less_pointees()`]]

8
doc/18_type_requirements.qbk
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@ -13,12 +13,12 @@ But this is practically useless. In order for `optional<T>` to be able to do any
optional<T> o;
o.emplace("T", "ctor", "params");
If `T` is `MoveConstructible`, `optional<T>` is also `MoveConstructible` and can be easily initialized from an rvalue of type `T` and be passed by value:
If `T` is __MOVE_CONSTRUCTIBLE__, `optional<T>` is also __MOVE_CONSTRUCTIBLE__ and can be easily initialized from an rvalue of type `T` and be passed by value:
optional<T> o = make_T();
optional<T> p = optional<T>();
If `T` is `CopyConstructible`, `optional<T>` is also `CopyConstructible` and can be easily initialized from an lvalue of type `T`:
If `T` is __COPY_CONSTRUCTIBLE__, `optional<T>` is also __COPY_CONSTRUCTIBLE__ and can be easily initialized from an lvalue of type `T`:
T v = make_T();
optional<T> o = v;
@ -29,9 +29,9 @@ If `T` is not `MoveAssignable`, it is still possible to reset the value of `opti
optional<const T> o = make_T();
o.emplace(make_another_T());
If `T` is `Moveable` (both `MoveConstructible` and `MoveAssignable`) then `optional<T>` is also `Moveable` and additionally can be constructed and assigned from an rvalue of type `T`.
If `T` is `Moveable` (both __MOVE_CONSTRUCTIBLE__ and `MoveAssignable`) then `optional<T>` is also `Moveable` and additionally can be constructed and assigned from an rvalue of type `T`.
Similarly, if `T` is `Copyable` (both `CopyConstructible` and `CopyAssignable`) then `optional<T>` is also `Copyable` and additionally can be constructed and assigned from an lvalue of type `T`.
Similarly, if `T` is `Copyable` (both __COPY_CONSTRUCTIBLE__ and `CopyAssignable`) then `optional<T>` is also `Copyable` and additionally can be constructed and assigned from an lvalue of type `T`.
`T` ['is not] required to be __SGI_DEFAULT_CONSTRUCTIBLE__.

25
doc/20_reference.qbk
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@ -80,12 +80,12 @@
T&& value() && ; ``[link reference_optional_value __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 __GO_TO__]``
template<class U> T value_or( U && v ) && ; ``[link reference_optional_value_or_move __GO_TO__]``
T const* get_ptr() const ; ``[link reference_optional_get_ptr __GO_TO__]``
T* get_ptr() ; ``[link reference_optional_get_ptr __GO_TO__]``
explicit operator bool() const ; ``[link reference_optional_operator_bool __GO_TO__]``
explicit operator bool() const noexcept ; ``[link reference_optional_operator_bool __GO_TO__]``
bool operator!() const noexcept ; ``[link reference_optional_operator_not __GO_TO__]``
@ -761,7 +761,7 @@ __SPACE__
of type `T` with `std::forward<Args>(args)...`.
* [*Postconditions: ] `*this` is [_initialized].
* [*Throws:] Whatever the selected `T`'s constructor throws.
* [*Notes:] `T` need not be `MoveConstructible` or `MoveAssignable`. On compilers that do not support variadic templates, the signature falls back to single-argument: `template<class Arg> void emplace(Arg&& arg)`. On compilers that do not support rvalue references, the signature falls back to two overloads: taking `const` and non-`const` lvalue reference.
* [*Notes:] `T` need not be __MOVE_CONSTRUCTIBLE__ or `MoveAssignable`. On compilers that do not support variadic templates, the signature falls back to single-argument: `template<class Arg> void emplace(Arg&& arg)`. On compilers that do not support rvalue references, the signature falls back to two overloads: taking `const` and non-`const` lvalue reference.
* [*Exception Safety:] If an exception is thrown during the initialization of `T`, `*this` is ['uninitialized].
* [*Example:]
``
@ -906,12 +906,22 @@ __SPACE__
[#reference_optional_value_or]
[: `template<class U> T optional<T>::value_or(U && v) const& ;`]
* [*Requires:] `T` is __COPY_CONSTRUCTIBLE__ and `U &&` is convertible to `T`.
* [*Returns:] `bool(*this) ? **this : static_cast<T>(forward<U>(v))`.
* [*Throws:] Any exception thrown by the selected constructor of `T`.
* [*Notes:] On compilers that do not support ref-qualifiers on member functions this overload is replaced with the `const`-qualified member function. On compilers without rvalue reference support the type of `v` becomes `U const&`.
__SPACE__
[#reference_optional_value_or_move]
[: `template<class U> T optional<T>::value_or(U && v) && ;`]
* [*Requires:] `T` is CopyConstructible.
* [*Returns:] First overload: `bool(*this) ? **this : static_cast<T>(forward<U>(v))`. second overload: `bool(*this) ? std::move(**this) : static_cast<T>(forward<U>(v))`.
* [*Requires:] `T` is __MOVE_CONSTRUCTIBLE__ and `U &&` is convertible to `T`.
* [*Returns:] `bool(*this) ? std::move(**this) : static_cast<T>(forward<U>(v))`.
* [*Throws:] Any exception thrown by the selected constructor of `T`.
* [*Notes:] 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. On compilers without rvalue reference support the type of `v` becomes `U const&`.
* [*Notes:] On compilers that do not support ref-qualifiers on member functions this overload is replaced with the classical non-`const`-qualified member function. On compilers without rvalue reference support the type of `v` becomes `U const&`.
__SPACE__
@ -989,10 +999,9 @@ __SPACE__
[#reference_optional_operator_bool]
[: `explicit optional<T>::operator bool() const ;`]
[: `explicit optional<T>::operator bool() const noexcept ;`]
* [*Returns:] `get_ptr() != 0`.
* [*Throws:] Nothing.
* [*Notes:] On compilers that do not support explicit conversion operators this falls back to safe-bool idiom.
* [*Example:]
``

52
doc/html/boost_optional/reference/detailed_semantics.html
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@ -1400,19 +1400,14 @@
<span class="keyword">const</span><span class="special">&amp;</span>
<span class="special">;</span></code>
</p></blockquote></div>
<div class="blockquote"><blockquote class="blockquote"><p>
<code class="computeroutput"><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">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;::</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></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="identifier">T</span></code>
is CopyConstructible.
is <a href="../../../../../utility/CopyConstructible.html" target="_top"><code class="computeroutput"><span class="identifier">CopyConstructible</span></code></a> and <code class="computeroutput"><span class="identifier">U</span> <span class="special">&amp;&amp;</span></code>
is convertible to <code class="computeroutput"><span class="identifier">T</span></code>.
</li>
<li class="listitem">
<span class="bold"><strong>Returns:</strong></span> First overload: <code class="computeroutput"><span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span> <span class="special">?</span> <span class="special">**</span><span class="keyword">this</span>
<span class="special">:</span> <span class="keyword">static_cast</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;(</span><span class="identifier">forward</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></code>. second overload: <code class="computeroutput"><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="keyword">this</span><span class="special">)</span> <span class="special">:</span> <span class="keyword">static_cast</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;(</span><span class="identifier">forward</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></code>.
<span class="bold"><strong>Returns:</strong></span> <code class="computeroutput"><span class="keyword">bool</span><span class="special">(*</span><span class="keyword">this</span><span class="special">)</span> <span class="special">?</span> <span class="special">**</span><span class="keyword">this</span> <span class="special">:</span> <span class="keyword">static_cast</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;(</span><span class="identifier">forward</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></code>.
</li>
<li class="listitem">
<span class="bold"><strong>Throws:</strong></span> Any exception thrown by the
@ -1420,13 +1415,42 @@
</li>
<li class="listitem">
<span class="bold"><strong>Notes:</strong></span> 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.
ref-qualifiers on member functions this overload is replaced with the
<code class="computeroutput"><span class="keyword">const</span></code>-qualified member function.
On compilers without rvalue reference support the type of <code class="computeroutput"><span class="identifier">v</span></code> becomes <code class="computeroutput"><span class="identifier">U</span>
<span class="keyword">const</span><span class="special">&amp;</span></code>.
</li>
</ul></div>
<p>
<span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span>
</p>
<a name="reference_optional_value_or_move"></a><div class="blockquote"><blockquote class="blockquote"><p>
<code class="computeroutput"><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">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;::</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></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="identifier">T</span></code>
is <code class="computeroutput"><span class="identifier">MoveConstructible</span></code>
and <code class="computeroutput"><span class="identifier">U</span> <span class="special">&amp;&amp;</span></code>
is convertible to <code class="computeroutput"><span class="identifier">T</span></code>.
</li>
<li class="listitem">
<span class="bold"><strong>Returns:</strong></span> <code class="computeroutput"><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="keyword">this</span><span class="special">)</span> <span class="special">:</span> <span class="keyword">static_cast</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;(</span><span class="identifier">forward</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></code>.
</li>
<li class="listitem">
<span class="bold"><strong>Throws:</strong></span> Any exception thrown by the
selected constructor of <code class="computeroutput"><span class="identifier">T</span></code>.
</li>
<li class="listitem">
<span class="bold"><strong>Notes:</strong></span> On compilers that do not support
ref-qualifiers on member functions this overload is replaced with the
classical non-<code class="computeroutput"><span class="keyword">const</span></code>-qualified
member function. On compilers without rvalue reference support the type
of <code class="computeroutput"><span class="identifier">v</span></code> becomes <code class="computeroutput"><span class="identifier">U</span> <span class="keyword">const</span><span class="special">&amp;</span></code>.
</li>
</ul></div>
<p>
<span class="inlinemediaobject"><img src="../../images/space.png" alt="space"></span>
</p>
@ -1572,15 +1596,13 @@
<a name="reference_optional_operator_bool"></a><div class="blockquote"><blockquote class="blockquote"><p>
<code class="computeroutput"><span class="keyword">explicit</span> <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="keyword">bool</span><span class="special">()</span>
<span class="keyword">const</span> <span class="special">;</span></code>
<span class="keyword">const</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="identifier">get_ptr</span><span class="special">()</span> <span class="special">!=</span> <span class="number">0</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> On compilers that do not support
explicit conversion operators this falls back to safe-bool idiom.

11
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@ -98,10 +98,11 @@
</p>
<p>
Such a <span class="emphasis"><em>de facto</em></span> idiom for referring to optional objects
can be formalized in the form of a concept: the <a href="../../../../../../utility/OptionalPointee.html" target="_top">OptionalPointee</a>
concept. This concept captures the syntactic usage of operators <code class="computeroutput"><span class="special">*</span></code>, <code class="computeroutput"><span class="special">-&gt;</span></code>
and contextual conversion to <code class="computeroutput"><span class="keyword">bool</span></code>
to convey the notion of optionality.
can be formalized in the form of a concept: the <a href="../../../../../../utility/OptionalPointee.html" target="_top"><code class="computeroutput"><span class="identifier">OptionalPointee</span></code></a> concept. This
concept captures the syntactic usage of operators <code class="computeroutput"><span class="special">*</span></code>,
<code class="computeroutput"><span class="special">-&gt;</span></code> and contextual conversion
to <code class="computeroutput"><span class="keyword">bool</span></code> to convey the notion
of optionality.
</p>
<p>
However, pointers are good to <span class="underline">refer</span>
@ -127,7 +128,7 @@
this semantics, so are inappropriate for the initialization and transport
of optional values, yet are quite convenient for handling the access to
the possible undefined value because of the idiomatic aid present in the
<a href="../../../../../../utility/OptionalPointee.html" target="_top">OptionalPointee</a>
<a href="../../../../../../utility/OptionalPointee.html" target="_top"><code class="computeroutput"><span class="identifier">OptionalPointee</span></code></a>
concept incarnated by pointers.
</p>
<h6>

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@ -31,9 +31,9 @@
One of the typical problems with wrappers and containers is that their interfaces
usually provide an operation to initialize or assign the contained object
as a copy of some other object. This not only requires the underlying type
to be <a href="../../../../../utility/CopyConstructible.html" target="_top">Copy Constructible</a>,
but also requires the existence of a fully constructed object, often temporary,
just to follow the copy from:
to be <a href="../../../../../utility/CopyConstructible.html" target="_top"><code class="computeroutput"><span class="identifier">CopyConstructible</span></code></a>, but also requires
the existence of a fully constructed object, often temporary, just to follow
the copy from:
</p>
<pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">X</span>
<span class="special">{</span>

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@ -60,10 +60,9 @@
<span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="identifier">p</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>
</pre>
<p>
If <code class="computeroutput"><span class="identifier">T</span></code> is <code class="computeroutput"><span class="identifier">CopyConstructible</span></code>,
<code class="computeroutput"><span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span></code> is
also <code class="computeroutput"><span class="identifier">CopyConstructible</span></code> and
can be easily initialized from an lvalue of type <code class="computeroutput"><span class="identifier">T</span></code>:
If <code class="computeroutput"><span class="identifier">T</span></code> is <a href="../../../../../utility/CopyConstructible.html" target="_top"><code class="computeroutput"><span class="identifier">CopyConstructible</span></code></a>, <code class="computeroutput"><span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span></code> is
also <a href="../../../../../utility/CopyConstructible.html" target="_top"><code class="computeroutput"><span class="identifier">CopyConstructible</span></code></a>
and can be easily initialized from an lvalue of type <code class="computeroutput"><span class="identifier">T</span></code>:
</p>
<pre class="programlisting"><span class="identifier">T</span> <span class="identifier">v</span> <span class="special">=</span> <span class="identifier">make_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="identifier">o</span> <span class="special">=</span> <span class="identifier">v</span><span class="special">;</span>
@ -85,10 +84,8 @@
can be constructed and assigned from an rvalue of type <code class="computeroutput"><span class="identifier">T</span></code>.
</p>
<p>
Similarly, if <code class="computeroutput"><span class="identifier">T</span></code> is <code class="computeroutput"><span class="identifier">Copyable</span></code> (both <code class="computeroutput"><span class="identifier">CopyConstructible</span></code>
and <code class="computeroutput"><span class="identifier">CopyAssignable</span></code>) then
<code class="computeroutput"><span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span></code> is
also <code class="computeroutput"><span class="identifier">Copyable</span></code> and additionally
Similarly, if <code class="computeroutput"><span class="identifier">T</span></code> is <code class="computeroutput"><span class="identifier">Copyable</span></code> (both <a href="../../../../../utility/CopyConstructible.html" target="_top"><code class="computeroutput"><span class="identifier">CopyConstructible</span></code></a> and <code class="computeroutput"><span class="identifier">CopyAssignable</span></code>) then <code class="computeroutput"><span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span></code>
is also <code class="computeroutput"><span class="identifier">Copyable</span></code> and additionally
can be constructed and assigned from an lvalue of type <code class="computeroutput"><span class="identifier">T</span></code>.
</p>
<p>

2
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@ -133,7 +133,7 @@
</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 08, 2014 at 18:14:37 GMT</small></p></td>
<td align="left"><p><small>Last revised: June 16, 2014 at 12:04:51 GMT</small></p></td>
<td align="right"><div class="copyright-footer"></div></td>
</tr></table>
<hr>

4
doc/html/optional/reference.html
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@ -104,12 +104,12 @@
<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"><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"><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>
<span class="identifier">T</span> <span class="keyword">const</span><span class="special">*</span> <span class="identifier">get_ptr</span><span class="special">()</span> <span class="keyword">const</span> <span class="special">;</span> <a class="link" href="../boost_optional/reference/detailed_semantics.html#reference_optional_get_ptr"><span class="inlinemediaobject"><img src="../images/callouts/R.png" alt="R"></span></a>
<span class="identifier">T</span><span class="special">*</span> <span class="identifier">get_ptr</span><span class="special">()</span> <span class="special">;</span> <a class="link" href="../boost_optional/reference/detailed_semantics.html#reference_optional_get_ptr"><span class="inlinemediaobject"><img src="../images/callouts/R.png" alt="R"></span></a>
<span class="keyword">explicit</span> <span class="keyword">operator</span> <span class="keyword">bool</span><span class="special">()</span> <span class="keyword">const</span> <span class="special">;</span> <a class="link" href="../boost_optional/reference/detailed_semantics.html#reference_optional_operator_bool"><span class="inlinemediaobject"><img src="../images/callouts/R.png" alt="R"></span></a>
<span class="keyword">explicit</span> <span class="keyword">operator</span> <span class="keyword">bool</span><span class="special">()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span> <span class="special">;</span> <a class="link" href="../boost_optional/reference/detailed_semantics.html#reference_optional_operator_bool"><span class="inlinemediaobject"><img src="../images/callouts/R.png" alt="R"></span></a>
<span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">!()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span> <span class="special">;</span> <a class="link" href="../boost_optional/reference/detailed_semantics.html#reference_optional_operator_not"><span class="inlinemediaobject"><img src="../images/callouts/R.png" alt="R"></span></a>

27
include/boost/optional/optional.hpp
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@ -23,6 +23,7 @@
#include <boost/config.hpp>
#include <boost/assert.hpp>
#include <boost/core/explicit_operator_bool.hpp>
#include <boost/optional/bad_optional_access.hpp>
#include <boost/static_assert.hpp>
#include <boost/throw_exception.hpp>
@ -34,6 +35,7 @@
#include <boost/type_traits/remove_reference.hpp>
#include <boost/type_traits/decay.hpp>
#include <boost/type_traits/is_base_of.hpp>
#include <boost/type_traits/is_convertible.hpp>
#include <boost/type_traits/is_lvalue_reference.hpp>
#include <boost/type_traits/is_nothrow_move_assignable.hpp>
#include <boost/type_traits/is_nothrow_move_constructible.hpp>
@ -49,7 +51,7 @@
#include <boost/utility/addressof.hpp>
#include <boost/utility/compare_pointees.hpp>
#include <boost/utility/enable_if.hpp>
#include <boost/utility/explicit_operator_bool.hpp>
#include <boost/utility/in_place_factory.hpp>
#include <boost/utility/swap.hpp>
@ -1059,23 +1061,36 @@ class optional : public optional_detail::optional_base<T>
#ifndef BOOST_NO_CXX11_REF_QUALIFIERS
template <class U>
value_type value_or ( U&& v ) const&
{ return this->is_initialized() ? get() : static_cast<value_type>(boost::forward<U>(v)); }
{
BOOST_STATIC_ASSERT((is_convertible<U&&, value_type>::value));
return this->is_initialized() ? get() : static_cast<value_type>(boost::forward<U>(v));
}
template <class U>
value_type value_or ( U&& v ) &&
{ return this->is_initialized() ? boost::move(get()) : static_cast<value_type>(boost::forward<U>(v)); }
{
BOOST_STATIC_ASSERT((is_convertible<U&&, value_type>::value));
return this->is_initialized() ? boost::move(get()) : static_cast<value_type>(boost::forward<U>(v));
}
#elif !defined BOOST_NO_CXX11_RVALUE_REFERENCES
template <class U>
value_type value_or ( U&& v ) const
{ return this->is_initialized() ? get() : static_cast<value_type>(boost::forward<U>(v)); }
{
BOOST_STATIC_ASSERT((is_convertible<U&&, value_type>::value));
return this->is_initialized() ? get() : static_cast<value_type>(boost::forward<U>(v));
}
#else
template <class U>
value_type value_or ( U const& v ) const { return this->is_initialized() ? get() : static_cast<value_type>(v); }
value_type value_or ( U const& v ) const
{
BOOST_STATIC_ASSERT((is_convertible<U const&, value_type>::value));
return this->is_initialized() ? get() : static_cast<value_type>(v);
}
#endif
bool operator!() const BOOST_NOEXCEPT { return !this->is_initialized() ; }
BOOST_EXPLICIT_OPERATOR_BOOL()
BOOST_EXPLICIT_OPERATOR_BOOL_NOEXCEPT()
} ;
#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES

1
test/Jamfile.v2
View File

@ -41,5 +41,6 @@ import testing ;
[ compile-fail optional_test_ref_fail_init_from_Urefref.cpp ]
[ compile-fail optional_test_ref_fail_assign_from_Trefref.cpp ]
[ compile-fail optional_test_ref_fail_assign_from_Urefref.cpp ]
[ compile-fail optional_test_fail_explicit_convert_in_value_or.cpp ]
;
}

32
test/optional_test_fail_explicit_convert_in_value_or.cpp Normal file
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@ -0,0 +1,32 @@
// Copyright (C) 2014, Andrzej Krzemienski.
//
// Use, modification, and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// See http://www.boost.org/lib/optional for documentation.
//
// You are welcome to contact the author at:
// akrzemi1@gmail.com
//
#include "boost/optional.hpp"
//
// THIS TEST SHOULD FAIL TO COMPILE
//
struct U
{};
struct T
{
explicit T(U const&) {}
};
void test_implicit_conversion_to_bool()
{
boost::optional<T> opt;
opt.value_or(U());
}