69 lines
4.7 KiB
HTML
69 lines
4.7 KiB
HTML
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<title>std::pmr::memory_resource::allocate</title>
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<h1 id="firstHeading" class="firstHeading"><span style="font-size:0.7em; line-height:130%">std::pmr::memory_resource::</span>allocate</h1>
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<div id="contentSub"><span class="subpages">< <a href="cpp.html">cpp</a>‎ | <a href="cpp-memory.html">memory</a>‎ | <a href="cpp-memory-memory_resource.html">memory resource</a></span></div>
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<div><span class="mw-geshi cpp source-cpp"><span class="kw4">void</span><span class="sy2">*</span> allocate<span class="br0">(</span><a href="cpp-types-size_t.html"><span class="kw100">std::<span class="me2">size_t</span></span></a> bytes,<br />
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<a href="cpp-types-size_t.html"><span class="kw100">std::<span class="me2">size_t</span></span></a> alignment <span class="sy1">=</span> alignof<span class="br0">(</span><a href="cpp-types-max_align_t.html"><span class="kw104">std::<span class="me2">max_align_t</span></span></a><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span></span></div>
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<td><span class="t-mark-rev t-since-cxx17">(C++17 起)</span><br />
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<span class="t-mark-rev t-until-cxx20">(C++20 前)</span></td>
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<div><span class="mw-geshi cpp source-cpp"><span class="br0">[</span><span class="br0">[</span>nodiscard<span class="br0">]</span><span class="br0">]</span> <span class="kw4">void</span><span class="sy2">*</span> allocate<span class="br0">(</span><a href="cpp-types-size_t.html"><span class="kw100">std::<span class="me2">size_t</span></span></a> bytes,<br />
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<a href="cpp-types-size_t.html"><span class="kw100">std::<span class="me2">size_t</span></span></a> alignment <span class="sy1">=</span> alignof<span class="br0">(</span><a href="cpp-types-max_align_t.html"><span class="kw104">std::<span class="me2">max_align_t</span></span></a><span class="br0">)</span><span class="br0">)</span><span class="sy4">;</span></span></div>
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<td><span class="t-mark-rev t-since-cxx20">(C++20 起)</span></td>
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<p>分配至少有 <code>bytes</code> 字节的存储。若支持这种对齐，则返回的存储对齐到指定的 <code>alignment</code> ，否则对齐到 <span class="t-c"><span class="mw-geshi cpp source-cpp">alignof<span class="br0">(</span><a href="cpp-types-max_align_t.html"><span class="kw104">std::<span class="me2">max_align_t</span></span></a><span class="br0">)</span></span></span> 。</p>
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<p>等价于 <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw1">return</span> do_allocate<span class="br0">(</span>bytes, alignment<span class="br0">)</span><span class="sy4">;</span></span></span> 。</p>
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<h3><span class="mw-headline" id=".E5.BC.82.E5.B8.B8">异常</span></h3>
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<p>若不能取得拥有要求的大小和对齐的存储，则抛出异常。</p>
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<h3><span class="mw-headline" id=".E5.8F.82.E9.98.85">参阅</span></h3>
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<div><a href="cpp-memory-memory_resource-do_allocate.html"><span class="t-lines"><span>do_allocate</span></span></a></div>
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<div><span class="t-lines"><span><span class="t-cmark">[虚]</span></span></span></div>
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<td>分配内存<br />
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<span class="t-mark">(虚私有成员函数)</span></td>
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