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href="oper_1_3_39_11_2_6_1_1_1_3.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 25</div> 26<div class="refentry"> 27<a name="boost.stl_interfaces.v1.view_interface"></a><div class="titlepage"></div> 28<div class="refnamediv"> 29<h2><span class="refentrytitle">Struct template view_interface</span></h2> 30<p>boost::stl_interfaces::v1::view_interface</p> 31</div> 32<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> 33<div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: <<a class="link" href="../../../stl_interfaces/reference.html#header.boost.stl_interfaces.view_interface_hpp" title="Header <boost/stl_interfaces/view_interface.hpp>">boost/stl_interfaces/view_interface.hpp</a>> 34 35</span><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Derived<span class="special">,</span> <span class="identifier">element_layout</span> Contiguity<span class="special">></span> 36<span class="keyword">struct</span> <a class="link" href="view_interface.html" title="Struct template view_interface">view_interface</a> <span class="special">{</span> 37 38 <span class="comment">// <a class="link" href="view_interface.html#id-1_3_39_11_2_6_1_1_1_1_3-bb">public member functions</a></span> 39 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">></span> 40 <span class="keyword">constexpr</span> <span class="keyword">auto</span> 41 <a class="link" href="view_interface.html#id-1_3_39_11_2_6_1_1_1_1_3_1-bb"><span class="identifier">empty</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">==</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">end</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span> 42 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">></span> 43 <span class="keyword">constexpr</span> <span class="keyword">auto</span> 44 <a class="link" href="view_interface.html#id-1_3_39_11_2_6_1_1_1_1_3_2-bb"><span class="identifier">empty</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="keyword">const</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">==</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="keyword">const</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">end</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span> 45 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">,</span> 46 <span class="keyword">typename</span> R <span class="special">=</span> <span class="keyword">decltype</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span><span class="identifier">D</span> <span class="special">&</span><span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">empty</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">></span> 47 <span class="keyword">explicit</span> <span class="keyword">constexpr</span> 48 <a class="link" href="view_interface.html#id-1_3_39_11_2_6_1_1_1_1_3_3-bb"><span class="keyword">operator</span> <span class="keyword">bool</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">empty</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span> 49 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">,</span> 50 <span class="keyword">typename</span> R <span class="special">=</span> <span class="keyword">decltype</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span><span class="identifier">D</span> <span class="keyword">const</span> <span class="special">&</span><span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">empty</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">></span> 51 <span class="keyword">explicit</span> <span class="keyword">constexpr</span> 52 <a class="link" href="view_interface.html#id-1_3_39_11_2_6_1_1_1_1_3_4-bb"><span class="keyword">operator</span> <span class="keyword">bool</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="keyword">const</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">empty</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span> 53 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">,</span> <span class="identifier">element_layout</span> C <span class="special">=</span> <span class="identifier">Contiguity</span><span class="special">,</span> 54 <span class="keyword">typename</span> Enable <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">enable_if_t</span><span class="special"><</span><span class="identifier">C</span> <span class="special">==</span> <span class="identifier">element_layout</span><span class="special">::</span><span class="identifier">contiguous</span><span class="special">></span> <span class="special">></span> 55 <span class="keyword">constexpr</span> <span class="keyword">auto</span> <a class="link" href="view_interface.html#id-1_3_39_11_2_6_1_1_1_1_3_5-bb"><span class="identifier">data</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span> 56 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">,</span> <span class="identifier">element_layout</span> C <span class="special">=</span> <span class="identifier">Contiguity</span><span class="special">,</span> 57 <span class="keyword">typename</span> Enable <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">enable_if_t</span><span class="special"><</span><span class="identifier">C</span> <span class="special">==</span> <span class="identifier">element_layout</span><span class="special">::</span><span class="identifier">contiguous</span><span class="special">></span> <span class="special">></span> 58 <span class="keyword">constexpr</span> <span class="keyword">auto</span> 59 <a class="link" href="view_interface.html#id-1_3_39_11_2_6_1_1_1_1_3_6-bb"><span class="identifier">data</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="keyword">const</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span> 60 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">></span> 61 <span class="keyword">constexpr</span> <span class="keyword">auto</span> 62 <a class="link" href="view_interface.html#id-1_3_39_11_2_6_1_1_1_1_3_7-bb"><span class="identifier">size</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">end</span><span class="special">(</span><span class="special">)</span> <span class="special">-</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span> 63 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">></span> 64 <span class="keyword">constexpr</span> <span class="keyword">auto</span> 65 <a class="link" href="view_interface.html#id-1_3_39_11_2_6_1_1_1_1_3_8-bb"><span class="identifier">size</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="keyword">const</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">end</span><span class="special">(</span><span class="special">)</span> <span class="special">-</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="keyword">const</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span> 66 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">></span> 67 <span class="keyword">constexpr</span> <span class="keyword">auto</span> <a class="link" href="view_interface.html#id-1_3_39_11_2_6_1_1_1_1_3_9-bb"><span class="identifier">front</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="special">*</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span> 68 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">></span> 69 <span class="keyword">constexpr</span> <span class="keyword">auto</span> 70 <a class="link" href="view_interface.html#id-1_3_39_11_2_6_1_1_1_1_3_10-bb"><span class="identifier">front</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="special">*</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="keyword">const</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span> 71 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">,</span> 72 <span class="keyword">typename</span> Enable <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">enable_if_t</span><span class="special"><</span> <a class="link" href="v1_dtl/decrementable_sentinel.html" title="Struct template decrementable_sentinel">v1_dtl::decrementable_sentinel</a><span class="special"><</span><span class="identifier">D</span><span class="special">></span><span class="special">::</span><span class="identifier">value</span> <span class="special">&&</span> <span class="identifier">v1_dtl</span><span class="special">::</span><span class="identifier">common_range</span><span class="special"><</span><span class="identifier">D</span><span class="special">></span><span class="special">::</span><span class="identifier">value</span><span class="special">></span> <span class="special">></span> 73 <span class="keyword">constexpr</span> <span class="keyword">auto</span> 74 <a class="link" href="view_interface.html#id-1_3_39_11_2_6_1_1_1_1_3_11-bb"><span class="identifier">back</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="special">*</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">prev</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">end</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span> 75 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">,</span> 76 <span class="keyword">typename</span> Enable <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">enable_if_t</span><span class="special"><</span> <a class="link" href="v1_dtl/decrementable_sentinel.html" title="Struct template decrementable_sentinel">v1_dtl::decrementable_sentinel</a><span class="special"><</span><span class="identifier">D</span><span class="special">></span><span class="special">::</span><span class="identifier">value</span> <span class="special">&&</span> <span class="identifier">v1_dtl</span><span class="special">::</span><span class="identifier">common_range</span><span class="special"><</span><span class="identifier">D</span><span class="special">></span><span class="special">::</span><span class="identifier">value</span><span class="special">></span> <span class="special">></span> 77 <span class="keyword">constexpr</span> <span class="keyword">auto</span> 78 <a class="link" href="view_interface.html#id-1_3_39_11_2_6_1_1_1_1_3_12-bb"><span class="identifier">back</span></a><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="special">*</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">prev</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="keyword">const</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">end</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span> 79 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">></span> 80 <span class="keyword">constexpr</span> <span class="keyword">auto</span> 81 <a class="link" href="view_interface.html#id-1_3_39_11_2_6_1_1_1_1_3_13-bb"><span class="keyword">operator</span><span class="special">[</span><span class="special">]</span></a><span class="special">(</span><span class="identifier">v1_dtl</span><span class="special">::</span><span class="identifier">range_difference_t</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">></span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">[</span><span class="identifier">n</span><span class="special">]</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span> 82 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">></span> 83 <span class="keyword">constexpr</span> <span class="keyword">auto</span> 84 <a class="link" href="view_interface.html#id-1_3_39_11_2_6_1_1_1_1_3_14-bb"><span class="keyword">operator</span><span class="special">[</span><span class="special">]</span></a><span class="special">(</span><span class="identifier">v1_dtl</span><span class="special">::</span><span class="identifier">range_difference_t</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">></span><span class="special">)</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="keyword">const</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">[</span><span class="identifier">n</span><span class="special">]</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span> 85<span class="special">}</span><span class="special">;</span></pre></div> 86<div class="refsect1"> 87<a name="id-1.3.39.11.2.6.3.4"></a><h2>Description</h2> 88<p>A CRTP template that one may derive from to make it easier to define <code class="computeroutput">std::ranges::view</code>-like types with a container-like interface. This is a pre-C++20 version of C++20's <code class="computeroutput"><a class="link" href="view_interface.html" title="Struct template view_interface">view_interface</a></code> (see [view.interface] in the C++ standard).</p> 89<p>The template parameter <code class="computeroutput">D</code> for <code class="computeroutput"><a class="link" href="view_interface.html" title="Struct template view_interface">view_interface</a></code> may be an incomplete type. Before any member of the resulting specialization of <code class="computeroutput"><a class="link" href="view_interface.html" title="Struct template view_interface">view_interface</a></code> other than special member functions is referenced, <code class="computeroutput">D</code> shall be complete, and model both <code class="computeroutput">std::derived_from<<a class="link" href="view_interface.html" title="Struct template view_interface">view_interface</a><D>></code> and <code class="computeroutput">std::view</code>. </p> 90<div class="refsect2"> 91<a name="id-1.3.39.11.2.6.3.4.4"></a><h3> 92<a name="id-1_3_39_11_2_6_1_1_1_1_3-bb"></a><code class="computeroutput">view_interface</code> public member functions</h3> 93<div class="orderedlist"><ol class="orderedlist" type="1"> 94<li class="listitem"><pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">></span> 95 <span class="keyword">constexpr</span> <span class="keyword">auto</span> 96 <a name="id-1_3_39_11_2_6_1_1_1_1_3_1-bb"></a><span class="identifier">empty</span><span class="special">(</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">==</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">end</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span></pre></li> 97<li class="listitem"><pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">></span> 98 <span class="keyword">constexpr</span> <span class="keyword">auto</span> 99 <a name="id-1_3_39_11_2_6_1_1_1_1_3_2-bb"></a><span class="identifier">empty</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="keyword">const</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">==</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="keyword">const</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">end</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span></pre></li> 100<li class="listitem"><pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">,</span> 101 <span class="keyword">typename</span> R <span class="special">=</span> <span class="keyword">decltype</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span><span class="identifier">D</span> <span class="special">&</span><span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">empty</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">></span> 102 <span class="keyword">explicit</span> <span class="keyword">constexpr</span> 103 <a name="id-1_3_39_11_2_6_1_1_1_1_3_3-bb"></a><span class="keyword">operator</span> <span class="keyword">bool</span><span class="special">(</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">empty</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span></pre></li> 104<li class="listitem"><pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">,</span> 105 <span class="keyword">typename</span> R <span class="special">=</span> <span class="keyword">decltype</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span><span class="identifier">D</span> <span class="keyword">const</span> <span class="special">&</span><span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">empty</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">></span> 106 <span class="keyword">explicit</span> <span class="keyword">constexpr</span> 107 <a name="id-1_3_39_11_2_6_1_1_1_1_3_4-bb"></a><span class="keyword">operator</span> <span class="keyword">bool</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="keyword">const</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">empty</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span></pre></li> 108<li class="listitem"><pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">,</span> <span class="identifier">element_layout</span> C <span class="special">=</span> <span class="identifier">Contiguity</span><span class="special">,</span> 109 <span class="keyword">typename</span> Enable <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">enable_if_t</span><span class="special"><</span><span class="identifier">C</span> <span class="special">==</span> <span class="identifier">element_layout</span><span class="special">::</span><span class="identifier">contiguous</span><span class="special">></span> <span class="special">></span> 110 <span class="keyword">constexpr</span> <span class="keyword">auto</span> <a name="id-1_3_39_11_2_6_1_1_1_1_3_5-bb"></a><span class="identifier">data</span><span class="special">(</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span></pre></li> 111<li class="listitem"><pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">,</span> <span class="identifier">element_layout</span> C <span class="special">=</span> <span class="identifier">Contiguity</span><span class="special">,</span> 112 <span class="keyword">typename</span> Enable <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">enable_if_t</span><span class="special"><</span><span class="identifier">C</span> <span class="special">==</span> <span class="identifier">element_layout</span><span class="special">::</span><span class="identifier">contiguous</span><span class="special">></span> <span class="special">></span> 113 <span class="keyword">constexpr</span> <span class="keyword">auto</span> 114 <a name="id-1_3_39_11_2_6_1_1_1_1_3_6-bb"></a><span class="identifier">data</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="keyword">const</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span></pre></li> 115<li class="listitem"><pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">></span> 116 <span class="keyword">constexpr</span> <span class="keyword">auto</span> 117 <a name="id-1_3_39_11_2_6_1_1_1_1_3_7-bb"></a><span class="identifier">size</span><span class="special">(</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">end</span><span class="special">(</span><span class="special">)</span> <span class="special">-</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span></pre></li> 118<li class="listitem"><pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">></span> 119 <span class="keyword">constexpr</span> <span class="keyword">auto</span> 120 <a name="id-1_3_39_11_2_6_1_1_1_1_3_8-bb"></a><span class="identifier">size</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="keyword">const</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">end</span><span class="special">(</span><span class="special">)</span> <span class="special">-</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="keyword">const</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span></pre></li> 121<li class="listitem"><pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">></span> 122 <span class="keyword">constexpr</span> <span class="keyword">auto</span> <a name="id-1_3_39_11_2_6_1_1_1_1_3_9-bb"></a><span class="identifier">front</span><span class="special">(</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="special">*</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span></pre></li> 123<li class="listitem"><pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">></span> 124 <span class="keyword">constexpr</span> <span class="keyword">auto</span> 125 <a name="id-1_3_39_11_2_6_1_1_1_1_3_10-bb"></a><span class="identifier">front</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="special">*</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="keyword">const</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span></pre></li> 126<li class="listitem"><pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">,</span> 127 <span class="keyword">typename</span> Enable <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">enable_if_t</span><span class="special"><</span> <a class="link" href="v1_dtl/decrementable_sentinel.html" title="Struct template decrementable_sentinel">v1_dtl::decrementable_sentinel</a><span class="special"><</span><span class="identifier">D</span><span class="special">></span><span class="special">::</span><span class="identifier">value</span> <span class="special">&&</span> <span class="identifier">v1_dtl</span><span class="special">::</span><span class="identifier">common_range</span><span class="special"><</span><span class="identifier">D</span><span class="special">></span><span class="special">::</span><span class="identifier">value</span><span class="special">></span> <span class="special">></span> 128 <span class="keyword">constexpr</span> <span class="keyword">auto</span> 129 <a name="id-1_3_39_11_2_6_1_1_1_1_3_11-bb"></a><span class="identifier">back</span><span class="special">(</span><span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="special">*</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">prev</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">end</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span></pre></li> 130<li class="listitem"><pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">,</span> 131 <span class="keyword">typename</span> Enable <span class="special">=</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">enable_if_t</span><span class="special"><</span> <a class="link" href="v1_dtl/decrementable_sentinel.html" title="Struct template decrementable_sentinel">v1_dtl::decrementable_sentinel</a><span class="special"><</span><span class="identifier">D</span><span class="special">></span><span class="special">::</span><span class="identifier">value</span> <span class="special">&&</span> <span class="identifier">v1_dtl</span><span class="special">::</span><span class="identifier">common_range</span><span class="special"><</span><span class="identifier">D</span><span class="special">></span><span class="special">::</span><span class="identifier">value</span><span class="special">></span> <span class="special">></span> 132 <span class="keyword">constexpr</span> <span class="keyword">auto</span> 133 <a name="id-1_3_39_11_2_6_1_1_1_1_3_12-bb"></a><span class="identifier">back</span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="special">*</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">prev</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="keyword">const</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">end</span><span class="special">(</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span></pre></li> 134<li class="listitem"><pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">></span> 135 <span class="keyword">constexpr</span> <span class="keyword">auto</span> 136 <a name="id-1_3_39_11_2_6_1_1_1_1_3_13-bb"></a><span class="keyword">operator</span><span class="special">[</span><span class="special">]</span><span class="special">(</span><span class="identifier">v1_dtl</span><span class="special">::</span><span class="identifier">range_difference_t</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">></span> n<span class="special">)</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">[</span><span class="identifier">n</span><span class="special">]</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span></pre></li> 137<li class="listitem"><pre class="literallayout"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> D <span class="special">=</span> <span class="identifier">Derived</span><span class="special">></span> 138 <span class="keyword">constexpr</span> <span class="keyword">auto</span> 139 <a name="id-1_3_39_11_2_6_1_1_1_1_3_14-bb"></a><span class="keyword">operator</span><span class="special">[</span><span class="special">]</span><span class="special">(</span><span class="identifier">v1_dtl</span><span class="special">::</span><span class="identifier">range_difference_t</span><span class="special"><</span> <span class="identifier">D</span> <span class="special">></span> n<span class="special">)</span> <span class="keyword">const</span> <span class="keyword">noexcept</span><span class="special">(</span><span class="keyword">noexcept</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">declval</span><span class="special"><</span> <span class="identifier">D</span> <span class="keyword">const</span> <span class="special">&</span> <span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">[</span><span class="identifier">n</span><span class="special">]</span><span class="special">)</span><span class="special">)</span><span class="special">)</span><span class="special">;</span></pre></li> 140</ol></div> 141</div> 142</div> 143</div> 144<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 145<td align="left"></td> 146<td align="right"><div class="copyright-footer">Copyright © 2019 T. Zachary Laine<p> 147 Distributed under the Boost Software License, Version 1.0. (See accompanying 148 file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) 149 </p> 150</div></td> 151</tr></table> 152<hr> 153<div class="spirit-nav"> 154<a accesskey="p" href="oper_1_3_39_11_2_5_1_1_1_9.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../../stl_interfaces/reference.html#header.boost.stl_interfaces.view_interface_hpp"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../index.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="oper_1_3_39_11_2_6_1_1_1_3.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 155</div> 156</body> 157</html> 158
