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boost-devel-doc-1.60.0-6.1.mga6.noarch.rpm

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<div class="section">
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="align.tutorial"></a><a class="link" href="tutorial.html" title="Tutorial">Tutorial</a>
</h2></div></div></div>
<div class="toc"><dl class="toc">
<dt><span class="section"><a href="tutorial.html#align.tutorial.align">align</a></span></dt>
<dt><span class="section"><a href="tutorial.html#align.tutorial.aligned_alloc">aligned_alloc and aligned_free</a></span></dt>
<dt><span class="section"><a href="tutorial.html#align.tutorial.aligned_allocator">aligned_allocator</a></span></dt>
<dt><span class="section"><a href="tutorial.html#align.tutorial.aligned_allocator_adaptor">aligned_allocator_adaptor</a></span></dt>
<dt><span class="section"><a href="tutorial.html#align.tutorial.aligned_delete">aligned_delete</a></span></dt>
<dt><span class="section"><a href="tutorial.html#align.tutorial.alignment_of">alignment_of</a></span></dt>
<dt><span class="section"><a href="tutorial.html#align.tutorial.assume_aligned">assume_aligned</a></span></dt>
<dt><span class="section"><a href="tutorial.html#align.tutorial.is_aligned">is_aligned</a></span></dt>
</dl></div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="align.tutorial.align"></a><a class="link" href="tutorial.html#align.tutorial.align" title="align">align</a>
</h3></div></div></div>
<p>
        The alignment function can be used to find the first address of a given alignment
        value within a given buffer of a given size. It adjusts the pointer provided,
        returns that value, and decreases space by the amount advanced, if the alignment
        succeeds, provided sufficient space in the buffer. Otherwise it yields a
        null pointer to indicate failure due to insufficient space.
      </p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">align</span><span class="special">/</span><span class="identifier">align</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">align</span><span class="special">/</span><span class="identifier">alignment_of</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="keyword">new</span><span class="special">&gt;</span>

<span class="keyword">struct</span> <span class="keyword">alignas</span><span class="special">(</span><span class="number">16</span><span class="special">)</span> <span class="identifier">type</span> <span class="special">{</span>
    <span class="keyword">float</span> <span class="identifier">data</span><span class="special">[</span><span class="number">4</span><span class="special">];</span>
<span class="special">};</span>

<span class="keyword">void</span> <span class="identifier">use</span><span class="special">(</span><span class="keyword">void</span><span class="special">*</span> <span class="identifier">ptr</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">size</span><span class="special">)</span>
<span class="special">{</span>
    <span class="keyword">auto</span> <span class="identifier">p</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">alignment</span><span class="special">::</span><span class="identifier">align</span><span class="special">(</span><span class="number">16</span><span class="special">,</span> <span class="keyword">sizeof</span><span class="special">(</span><span class="identifier">type</span><span class="special">),</span> <span class="identifier">ptr</span><span class="special">,</span> <span class="identifier">size</span><span class="special">);</span>
    <span class="keyword">if</span> <span class="special">(</span><span class="identifier">p</span><span class="special">)</span> <span class="special">{</span>
        <span class="keyword">auto</span> <span class="identifier">q</span> <span class="special">=</span> <span class="special">::</span><span class="keyword">new</span><span class="special">(</span><span class="identifier">p</span><span class="special">)</span> <span class="identifier">type</span><span class="special">;</span>
        <span class="identifier">q</span><span class="special">-&gt;~</span><span class="identifier">type</span><span class="special">();</span>
    <span class="special">}</span>
<span class="special">}</span>

<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
<span class="special">{</span>
    <span class="keyword">char</span> <span class="identifier">c</span><span class="special">[</span><span class="number">64</span><span class="special">];</span>
    <span class="identifier">use</span><span class="special">(</span><span class="identifier">c</span><span class="special">,</span> <span class="keyword">sizeof</span> <span class="identifier">c</span><span class="special">);</span>
<span class="special">}</span>
</pre>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="align.tutorial.aligned_alloc"></a><a class="link" href="tutorial.html#align.tutorial.aligned_alloc" title="aligned_alloc and aligned_free">aligned_alloc and aligned_free</a>
</h3></div></div></div>
<p>
        Consider these functions alignment enabled versions of <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">malloc</span></code>,
        <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">free</span></code> or <code class="computeroutput"><span class="special">::</span><span class="keyword">operator</span> <span class="keyword">new</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">no_throw_t</span><span class="special">&amp;)</span></code>, <code class="computeroutput"><span class="special">::</span><span class="keyword">operator</span> <span class="keyword">delete</span><span class="special">(</span><span class="keyword">void</span><span class="special">*)</span></code>.
        The aligned allocation function allocates space with the specified size and
        alignment. The aligned deallocation function can then deallocate this space.
      </p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">align</span><span class="special">/</span><span class="identifier">aligned_alloc</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>

<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
<span class="special">{</span>
    <span class="keyword">void</span><span class="special">*</span> <span class="identifier">p</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">alignment</span><span class="special">::</span><span class="identifier">aligned_alloc</span><span class="special">(</span><span class="number">16</span><span class="special">,</span> <span class="number">100</span><span class="special">);</span>
    <span class="keyword">if</span> <span class="special">(</span><span class="identifier">p</span><span class="special">)</span> <span class="special">{</span>
        <span class="identifier">boost</span><span class="special">::</span><span class="identifier">alignment</span><span class="special">::</span><span class="identifier">aligned_free</span><span class="special">(</span><span class="identifier">p</span><span class="special">);</span>
    <span class="special">}</span>
<span class="special">}</span>
</pre>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="align.tutorial.aligned_allocator"></a><a class="link" href="tutorial.html#align.tutorial.aligned_allocator" title="aligned_allocator">aligned_allocator</a>
</h3></div></div></div>
<p>
        Consider this class template a superior version of the default allocator,
        <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">allocator</span></code>, because it can be used with
        types that are over-aligned.
      </p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">align</span><span class="special">/</span><span class="identifier">aligned_allocator</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">vector</span><span class="special">&gt;</span>

<span class="keyword">struct</span> <span class="keyword">alignas</span><span class="special">(</span><span class="number">16</span><span class="special">)</span> <span class="identifier">type</span> <span class="special">{</span>
    <span class="keyword">float</span> <span class="identifier">data</span><span class="special">[</span><span class="number">4</span><span class="special">];</span>
<span class="special">};</span>

<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
<span class="special">{</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special">&lt;</span><span class="identifier">type</span><span class="special">,</span>
        <span class="identifier">boost</span><span class="special">::</span><span class="identifier">alignment</span><span class="special">::</span><span class="identifier">aligned_allocator</span><span class="special">&lt;</span><span class="identifier">type</span><span class="special">&gt;</span> <span class="special">&gt;</span> <span class="identifier">v</span><span class="special">;</span>
    <span class="identifier">v</span><span class="special">.</span><span class="identifier">emplace_back</span><span class="special">();</span>
<span class="special">}</span>
</pre>
<p>
        The optional template parameter of this class allows specifying a minimum
        alignment to use for allocations. The default minimum alignment is 1.
      </p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">align</span><span class="special">/</span><span class="identifier">aligned_allocator</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">vector</span><span class="special">&gt;</span>

<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
<span class="special">{</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special">&lt;</span><span class="keyword">char</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">alignment</span><span class="special">::</span>
        <span class="identifier">aligned_allocator</span><span class="special">&lt;</span><span class="keyword">char</span><span class="special">,</span> <span class="number">16</span><span class="special">&gt;</span> <span class="special">&gt;</span> <span class="identifier">v</span><span class="special">;</span>
    <span class="identifier">v</span><span class="special">.</span><span class="identifier">emplace_back</span><span class="special">();</span>
<span class="special">}</span>
</pre>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="align.tutorial.aligned_allocator_adaptor"></a><a class="link" href="tutorial.html#align.tutorial.aligned_allocator_adaptor" title="aligned_allocator_adaptor">aligned_allocator_adaptor</a>
</h3></div></div></div>
<p>
        This class template can turn any existing allocator type, C++11 or C++03,
        stateful or stateless, into one that supports types which are over-aligned.
      </p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">align</span><span class="special">/</span><span class="identifier">aligned_allocator_adaptor</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">vector</span><span class="special">&gt;</span>

<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Allocator</span><span class="special">&gt;</span>
<span class="keyword">class</span> <span class="identifier">utility</span> <span class="special">{</span>
<span class="keyword">public</span><span class="special">:</span>
    <span class="keyword">void</span> <span class="identifier">add</span><span class="special">()</span> <span class="special">{</span>
        <span class="identifier">v</span><span class="special">.</span><span class="identifier">emplace_back</span><span class="special">();</span>
    <span class="special">}</span>
<span class="keyword">private</span><span class="special">:</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">alignment</span><span class="special">::</span>
        <span class="identifier">aligned_allocator_adaptor</span><span class="special">&lt;</span><span class="identifier">Allocator</span><span class="special">&gt;</span> <span class="special">&gt;</span> <span class="identifier">v</span><span class="special">;</span>
<span class="special">};</span>

<span class="keyword">struct</span> <span class="keyword">alignas</span><span class="special">(</span><span class="number">16</span><span class="special">)</span> <span class="identifier">type</span> <span class="special">{</span>
    <span class="keyword">float</span> <span class="identifier">data</span><span class="special">[</span><span class="number">4</span><span class="special">];</span>
<span class="special">};</span>

<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
<span class="special">{</span>
    <span class="identifier">utility</span><span class="special">&lt;</span><span class="identifier">type</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">allocator</span><span class="special">&lt;</span><span class="identifier">type</span><span class="special">&gt;</span> <span class="special">&gt;</span> <span class="identifier">u</span><span class="special">;</span>
    <span class="identifier">u</span><span class="special">.</span><span class="identifier">add</span><span class="special">();</span>
<span class="special">}</span>
</pre>
<p>
        The optional template parameter of this class allows specifying a minimum
        alignment to use for allocations. The default minimum alignment is 1.
      </p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">align</span><span class="special">/</span><span class="identifier">aligned_allocator_adaptor</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">vector</span><span class="special">&gt;</span>

<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">Allocator</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">Alignment</span><span class="special">&gt;</span>
<span class="keyword">class</span> <span class="identifier">utility</span> <span class="special">{</span>
<span class="keyword">public</span><span class="special">:</span>
    <span class="keyword">void</span> <span class="identifier">add</span><span class="special">()</span> <span class="special">{</span>
        <span class="identifier">v</span><span class="special">.</span><span class="identifier">v</span><span class="special">.</span><span class="identifier">emplace_back</span><span class="special">();</span>
    <span class="special">}</span>
<span class="keyword">private</span><span class="special">:</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">alignment</span><span class="special">::</span>
        <span class="identifier">aligned_allocator_adaptor</span><span class="special">&lt;</span><span class="identifier">Allocator</span><span class="special">,</span> <span class="identifier">Alignment</span><span class="special">&gt;</span> <span class="special">&gt;</span> <span class="identifier">v</span><span class="special">;</span>
<span class="special">};</span>

<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
<span class="special">{</span>
    <span class="identifier">utility</span><span class="special">&lt;</span><span class="keyword">char</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">allocator</span><span class="special">&lt;</span><span class="keyword">char</span><span class="special">&gt;,</span> <span class="number">16</span><span class="special">&gt;</span> <span class="identifier">u</span><span class="special">;</span>
    <span class="identifier">u</span><span class="special">.</span><span class="identifier">add</span><span class="special">();</span>
<span class="special">}</span>
</pre>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="align.tutorial.aligned_delete"></a><a class="link" href="tutorial.html#align.tutorial.aligned_delete" title="aligned_delete">aligned_delete</a>
</h3></div></div></div>
<p>
        Consider this class an alignment aware version of the class template <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">default_delete</span></code>.
        It is a deleter that destroys the object and then deallocates space using
        our aligned deallocation function. It should be used with constructed objects
        that were allocated with our aligned allocation function and is useful with
        deleter enabled types like <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span></code>.
      </p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">align</span><span class="special">/</span><span class="identifier">aligned_delete</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">memory</span><span class="special">&gt;</span>

<span class="keyword">struct</span> <span class="keyword">alignas</span><span class="special">(</span><span class="number">16</span><span class="special">)</span> <span class="identifier">type</span> <span class="special">{</span>
    <span class="keyword">float</span> <span class="identifier">data</span><span class="special">[</span><span class="number">4</span><span class="special">];</span>
<span class="special">};</span>

<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
<span class="special">{</span>
    <span class="keyword">void</span><span class="special">*</span> <span class="identifier">p</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">alignment</span><span class="special">::</span><span class="identifier">aligned_alloc</span><span class="special">(</span><span class="number">16</span><span class="special">,</span> <span class="keyword">sizeof</span><span class="special">(</span><span class="identifier">type</span><span class="special">));</span>
    <span class="keyword">if</span> <span class="special">(</span><span class="identifier">p</span><span class="special">)</span> <span class="special">{</span>
       <span class="identifier">type</span><span class="special">*</span> <span class="identifier">q</span> <span class="special">=</span> <span class="special">::</span><span class="keyword">new</span><span class="special">(</span><span class="identifier">p</span><span class="special">)</span> <span class="identifier">type</span><span class="special">;</span>
       <span class="identifier">std</span><span class="special">::</span><span class="identifier">unique_ptr</span><span class="special">&lt;</span><span class="identifier">type</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">alignment</span><span class="special">::</span><span class="identifier">aligned_delete</span><span class="special">&gt;(</span><span class="identifier">q</span><span class="special">);</span>
    <span class="special">}</span>
<span class="special">}</span>
</pre>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="align.tutorial.alignment_of"></a><a class="link" href="tutorial.html#align.tutorial.alignment_of" title="alignment_of">alignment_of</a>
</h3></div></div></div>
<p>
        This type trait can be used to query the alignment requirement of a type
        at compile time.
      </p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">align</span><span class="special">/</span><span class="identifier">alignment_of</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">type_traits</span><span class="special">&gt;</span>

<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span>
<span class="keyword">class</span> <span class="identifier">utility</span> <span class="special">{</span>
<span class="keyword">public</span><span class="special">:</span>
    <span class="keyword">void</span> <span class="identifier">construct</span><span class="special">()</span> <span class="special">{</span>
        <span class="keyword">void</span><span class="special">*</span> <span class="identifier">p</span> <span class="special">=</span> <span class="special">&amp;</span><span class="identifier">v</span><span class="special">;</span>
        <span class="special">::</span><span class="keyword">new</span><span class="special">(</span><span class="identifier">p</span><span class="special">)</span> <span class="identifier">T</span><span class="special">();</span>
    <span class="special">}</span>
<span class="keyword">private</span><span class="special">:</span>
    <span class="identifier">std</span><span class="special">::</span><span class="identifier">aligned_storage_t</span><span class="special">&lt;</span><span class="keyword">sizeof</span><span class="special">(</span><span class="identifier">T</span><span class="special">),</span>
        <span class="identifier">boost</span><span class="special">::</span><span class="identifier">alignment</span><span class="special">::</span><span class="identifier">alignment_of</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;::</span><span class="identifier">value</span><span class="special">&gt;</span> <span class="identifier">v</span><span class="special">;</span>
<span class="special">};</span>

<span class="keyword">struct</span> <span class="keyword">alignas</span><span class="special">(</span><span class="number">16</span><span class="special">)</span> <span class="identifier">type</span> <span class="special">{</span>
    <span class="keyword">float</span> <span class="identifier">data</span><span class="special">[</span><span class="number">4</span><span class="special">];</span>
<span class="special">};</span>

<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
<span class="special">{</span>
    <span class="identifier">utility</span><span class="special">&lt;</span><span class="identifier">type</span><span class="special">&gt;</span> <span class="identifier">u</span><span class="special">;</span>
    <span class="identifier">u</span><span class="special">.</span><span class="identifier">construct</span><span class="special">();</span>
<span class="special">}</span>
</pre>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="align.tutorial.assume_aligned"></a><a class="link" href="tutorial.html#align.tutorial.assume_aligned" title="assume_aligned">assume_aligned</a>
</h3></div></div></div>
<p>
        This macro is used to notify the compiler of a given pointer variable's alignment.
        It is useful for guide optimizing compilers into vectorizing or applying
        other compiler specific, alignment related optimizations.
      </p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">align</span><span class="special">/</span><span class="identifier">assume_aligned</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>

<span class="keyword">void</span> <span class="identifier">use</span><span class="special">(</span><span class="keyword">double</span><span class="special">*</span> <span class="identifier">array</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">size</span><span class="special">)</span>
<span class="special">{</span>
    <span class="identifier">BOOST_ALIGN_ASSUME_ALIGNED</span><span class="special">(</span><span class="identifier">array</span><span class="special">,</span> <span class="number">16</span><span class="special">);</span>
    <span class="keyword">for</span> <span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">i</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> <span class="identifier">i</span> <span class="special">&lt;</span> <span class="identifier">size</span><span class="special">;</span> <span class="identifier">i</span><span class="special">++)</span> <span class="special">{</span>
        <span class="identifier">array</span><span class="special">[</span><span class="identifier">i</span><span class="special">]++;</span>
    <span class="special">}</span>
<span class="special">}</span>

<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
<span class="special">{</span>
    <span class="keyword">alignas</span><span class="special">(</span><span class="number">16</span><span class="special">)</span> <span class="keyword">double</span> <span class="identifier">d</span><span class="special">[</span><span class="number">4</span><span class="special">]</span> <span class="special">{</span> <span class="special">};</span>
    <span class="identifier">use</span><span class="special">(</span><span class="identifier">d</span><span class="special">,</span> <span class="number">4</span><span class="special">);</span>
<span class="special">}</span>
</pre>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="align.tutorial.is_aligned"></a><a class="link" href="tutorial.html#align.tutorial.is_aligned" title="is_aligned">is_aligned</a>
</h3></div></div></div>
<p>
        This function is used to compare the alignment of a pointer. It is useful
        in assertions that validate a pointer value is aligned on a given boundary.
      </p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">align</span><span class="special">/</span><span class="identifier">is_aligned</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">cassert</span><span class="special">&gt;</span>

<span class="keyword">void</span> <span class="identifier">use</span><span class="special">(</span><span class="keyword">void</span><span class="special">*</span> <span class="identifier">ptr</span><span class="special">)</span>
<span class="special">{</span>
    <span class="identifier">assert</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">alignment</span><span class="special">::</span><span class="identifier">is_aligned</span><span class="special">(</span><span class="identifier">ptr</span><span class="special">,</span> <span class="number">16</span><span class="special">));</span>
<span class="special">}</span>

<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
<span class="special">{</span>
    <span class="keyword">alignas</span><span class="special">(</span><span class="number">16</span><span class="special">)</span> <span class="keyword">char</span> <span class="identifier">c</span><span class="special">[</span><span class="number">64</span><span class="special">];</span>
    <span class="identifier">use</span><span class="special">(</span><span class="identifier">c</span><span class="special">);</span>
<span class="special">}</span>
</pre>
</div>
</div>
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<td align="right"><div class="copyright-footer">Copyright &#169; 2014, 2015 Glen Joseph Fernandes<p>
        Distributed under the Boost Software License, Version 1.0.
      </p>
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