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<header data-kunai-mdinfo="{"meta": {"header": ["numeric"], "namespace": ["std"], "id-type": ["function template"]}, "sources": [{"id": "e2c19572467c6008d00435417863ec8296824daa", "source": "#include <iostream>\n#include <numeric>\n#include <vector>\n\ntemplate <class Range>\nvoid print(const Range& r)\n{\n for(const auto& x : r)\n std::cout << x << \" --> \";\n std::cout << \"end\" << std::endl;\n}\n\nint main()\n{\n std::vector<double> v = {0.0, 0.2, 0.4, 0.6, 0.8};\n std::vector<double> diffs(v.size());\n\n // (1) : operator-()\u3092\u4f7f\u7528\u3057\u3066\u3001\u96a3\u63a5\u8981\u7d20\u306e\u5dee\u3092\u8a08\u7b97\u3059\u308b\n std::adjacent_difference(v.cbegin(), v.cend(), diffs.begin());\n print(diffs);\n\n // (2) : \u6700\u5f8c\u306e\u5f15\u6570\u3068\u3057\u3066\u4e0e\u3048\u305f\u4efb\u610f\u306e2\u9805\u6f14\u7b97\u95a2\u6570\u306b\u3088\u3063\u3066\u3001\n // \u96a3\u63a5\u8981\u7d20\u306e\u5dee\u3092\u8a08\u7b97\u3059\u308b\n std::adjacent_difference(v.cbegin(), v.cend(), diffs.begin(),\n [](double a, double b) {\n return a*a - b*b; // 2\u70b9\u9593\u306e\u8ddd\u96e2\u306e\u8a08\u7b97\n });\n print(diffs);\n}\n"}], "page_id": ["reference", "numeric", "adjacent_difference"]}">
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最終更新日時(UTC):
<span itemprop="datePublished" content="2022-12-28T02:13:14">
2022年12月28日 02時13分14秒
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<span itemprop="author" itemscope itemtype="http://schema.org/Person">
<span itemprop="name">Akira Takahashi</span>
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<div class="identifier-type">function template</div><div class="header"><numeric></div><h1 itemprop="name"><span class="namespace" title="namespace std">std::</span><span class="token">adjacent_difference</span></h1>
<div itemprop="articleBody"><p><div class="codehilite"><pre><span></span><code><span class="k">namespace</span><span class="w"> </span><span class="nn">std</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="k">template</span><span class="w"> </span><span class="o"><</span><span class="k">class</span><span class="w"> </span><span class="nc">InputIterator</span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">OutputIterator</span><span class="o">></span>
<span class="w"> </span><span class="n">OutputIterator</span>
<span class="w"> </span><span class="n">adjacent_difference</span><span class="p">(</span><span class="n">InputIterator</span><span class="w"> </span><span class="n">first</span><span class="p">,</span>
<span class="w"> </span><span class="n">InputIterator</span><span class="w"> </span><span class="n">last</span><span class="p">,</span>
<span class="w"> </span><span class="n">OutputIterator</span><span class="w"> </span><span class="n">result</span><span class="p">);</span><span class="w"> </span><span class="c1">// (1) C++03</span>
<span class="w"> </span><span class="k">template</span><span class="w"> </span><span class="o"><</span><span class="k">class</span><span class="w"> </span><span class="nc">InputIterator</span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">OutputIterator</span><span class="o">></span>
<span class="w"> </span><span class="k">constexpr</span><span class="w"> </span><span class="n">OutputIterator</span>
<span class="w"> </span><span class="n">adjacent_difference</span><span class="p">(</span><span class="n">InputIterator</span><span class="w"> </span><span class="n">first</span><span class="p">,</span>
<span class="w"> </span><span class="n">InputIterator</span><span class="w"> </span><span class="n">last</span><span class="p">,</span>
<span class="w"> </span><span class="n">OutputIterator</span><span class="w"> </span><span class="n">result</span><span class="p">);</span><span class="w"> </span><span class="c1">// (1) C++20</span>
<span class="w"> </span><span class="k">template</span><span class="w"> </span><span class="o"><</span><span class="k">class</span><span class="w"> </span><span class="nc">InputIterator</span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">OutputIterator</span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">BinaryOperation</span><span class="o">></span>
<span class="w"> </span><span class="n">OutputIterator</span>
<span class="w"> </span><span class="n">adjacent_difference</span><span class="p">(</span><span class="n">InputIterator</span><span class="w"> </span><span class="n">first</span><span class="p">,</span>
<span class="w"> </span><span class="n">InputIterator</span><span class="w"> </span><span class="n">last</span><span class="p">,</span>
<span class="w"> </span><span class="n">OutputIterator</span><span class="w"> </span><span class="n">result</span><span class="p">,</span>
<span class="w"> </span><span class="n">BinaryOperation</span><span class="w"> </span><span class="n">binary_op</span><span class="p">);</span><span class="w"> </span><span class="c1">// (2) C++03</span>
<span class="w"> </span><span class="k">template</span><span class="w"> </span><span class="o"><</span><span class="k">class</span><span class="w"> </span><span class="nc">InputIterator</span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">OutputIterator</span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">BinaryOperation</span><span class="o">></span>
<span class="w"> </span><span class="k">constexpr</span><span class="w"> </span><span class="n">OutputIterator</span>
<span class="w"> </span><span class="n">adjacent_difference</span><span class="p">(</span><span class="n">InputIterator</span><span class="w"> </span><span class="n">first</span><span class="p">,</span>
<span class="w"> </span><span class="n">InputIterator</span><span class="w"> </span><span class="n">last</span><span class="p">,</span>
<span class="w"> </span><span class="n">OutputIterator</span><span class="w"> </span><span class="n">result</span><span class="p">,</span>
<span class="w"> </span><span class="n">BinaryOperation</span><span class="w"> </span><span class="n">binary_op</span><span class="p">);</span><span class="w"> </span><span class="c1">// (2) C++20</span>
<span class="w"> </span><span class="k">template</span><span class="w"> </span><span class="o"><</span><span class="k">class</span><span class="w"> </span><span class="nc"><a href="../execution/execution/execution_policy.html">ExecutionPolicy</a></span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">ForwardIterator1</span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">ForwardIterator2</span><span class="o">></span>
<span class="w"> </span><span class="n">ForwardIterator2</span>
<span class="w"> </span><span class="n">adjacent_difference</span><span class="p">(</span><span class="n"><a href="../execution/execution/execution_policy.html">ExecutionPolicy</a></span><span class="o">&&</span><span class="w"> </span><span class="n">exec</span><span class="p">,</span>
<span class="w"> </span><span class="n">ForwardIterator1</span><span class="w"> </span><span class="n">first</span><span class="p">,</span>
<span class="w"> </span><span class="n">ForwardIterator1</span><span class="w"> </span><span class="n">last</span><span class="p">,</span>
<span class="w"> </span><span class="n">ForwardIterator2</span><span class="w"> </span><span class="n">result</span><span class="p">);</span><span class="w"> </span><span class="c1">// (3) C++17</span>
<span class="w"> </span><span class="k">template</span><span class="w"> </span><span class="o"><</span><span class="k">class</span><span class="w"> </span><span class="nc"><a href="../execution/execution/execution_policy.html">ExecutionPolicy</a></span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">ForwardIterator1</span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">ForwardIterator2</span><span class="p">,</span>
<span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">BinaryOperation</span><span class="o">></span>
<span class="w"> </span><span class="n">ForwardIterator2</span>
<span class="w"> </span><span class="n">adjacent_difference</span><span class="p">(</span><span class="n"><a href="../execution/execution/execution_policy.html">ExecutionPolicy</a></span><span class="o">&&</span><span class="w"> </span><span class="n">exec</span><span class="p">,</span>
<span class="w"> </span><span class="n">ForwardIterator1</span><span class="w"> </span><span class="n">first</span><span class="p">,</span>
<span class="w"> </span><span class="n">ForwardIterator1</span><span class="w"> </span><span class="n">last</span><span class="p">,</span>
<span class="w"> </span><span class="n">ForwardIterator2</span><span class="w"> </span><span class="n">result</span><span class="p">,</span>
<span class="w"> </span><span class="n">BinaryOperation</span><span class="w"> </span><span class="n">binary_op</span><span class="p">);</span><span class="w"> </span><span class="c1">// (4) C++17</span>
<span class="p">}</span>
</code></pre></div>
</p>
<h2>概要</h2>
<p>隣接する要素間の差を計算する。</p>
<p>この関数に与えられた<a class="cpprefjp-defined-word" data-desc="2つのイテレータで表現される半開区間を表す。C++20からイテレータと番兵で異なる型であっても指定可能になる">イテレータ範囲</a><code>[first, last)</code>を<code>r</code>として、その範囲の隣接する要素同士の差を、<code>{r[0], r[1] - r[0], r[2] - r[1], r[3] - r[2], r[4] - r[3]}</code>のように演算して求められた新たな範囲を返す。</p>
<ul>
<li>(1), (3) : 各隣接要素<code>a</code>と<code>b</code>を<code>operator-(b, a)</code>で減算した結果を、<code>result</code>出力イテレータに書き込む</li>
<li>(2), (4) : 各隣接要素<code>a</code>と<code>b</code>を<code>binary_op(b, a)</code>で減算した結果を、<code>result</code>出力イテレータに書き込む</li>
</ul>
<h2>要件</h2>
<ul>
<li>(2) :<ul>
<li>C++03まで : 関数オブジェクト<code>binary_op</code>の呼び出しは、副作用を起こしてはならない</li>
<li>C++11から : 関数オブジェクト<code>binary_op</code>の呼び出しが、<a class="cpprefjp-defined-word" data-desc="2つのイテレータで表現される半開区間を表す。C++20からイテレータと番兵で異なる型であっても指定可能になる">イテレータ範囲</a><code>[first, last]</code>および<a class="cpprefjp-defined-word" data-desc="2つのイテレータで表現される半開区間を表す。C++20からイテレータと番兵で異なる型であっても指定可能になる">イテレータ範囲</a><code>[result, result + (last - first)]</code>の要素変更、イテレータの無効化をしてはならない</li>
</ul>
</li>
<li>(3), (4) :<ul>
<li><a class="cpprefjp-defined-word" data-desc="2つのイテレータで表現される半開区間を表す。C++20からイテレータと番兵で異なる型であっても指定可能になる">イテレータ範囲</a><code>[first, last)</code>と<a class="cpprefjp-defined-word" data-desc="2つのイテレータで表現される半開区間を表す。C++20からイテレータと番兵で異なる型であっても指定可能になる">イテレータ範囲</a><code>[result, result + (last - first))</code>は重なってはならない</li>
</ul>
</li>
</ul>
<h2><a class="cpprefjp-defined-word" data-desc="関数等の意味論を構成する要素の1つ。Constraints。関数であればオーバーロード解決に参加するための条件、それ以外であれば受け付ける型の条件">テンプレートパラメータ制約</a></h2>
<ul>
<li>(1) :<ul>
<li>C++11から : <code>InputIterator</code>が指す値の型が、<a href="../type_traits/is_move_assignable.html">ムーブ代入可能</a>であり、<code>*first</code>で初期化でき、<code>result</code>出力イテレータに書き込めること</li>
<li>C++11からC++17まで : <code>InputIterator</code>が指す値の型のオブジェクト<code>a</code>と<code>b</code>において、式<code>b - a</code>の結果が<code>result</code>出力イテレータに書き込めること</li>
<li>C++20から : <code>InputIterator</code>が指す値の型のオブジェクト<code>a</code>と<code>b</code>において、式<code>b - <a href="../utility/move.html">std::move</a>(a)</code>の結果が<code>result</code>出力イテレータに書き込めること</li>
</ul>
</li>
<li>(2) <ul>
<li>C++11から : <code>InputIterator</code>が指す値の型が、<a href="../type_traits/is_move_assignable.html">ムーブ代入可能</a>であり、<code>*first</code>で初期化でき、<code>result</code>出力イテレータに書き込めること</li>
<li>C++11からC++17まで : <code>InputIterator</code>が指す値の型のオブジェクト<code>a</code>と<code>b</code>において、式<code>binary_op(b, a)</code>の結果が<code>result</code>出力イテレータに書き込めること</li>
<li>C++20から : <code>InputIterator</code>が指す値の型のオブジェクト<code>a</code>と<code>b</code>において、式<code>binary_op(b, <a href="../utility/move.html">std::move</a>(a))</code>の結果が<code>result</code>出力イテレータに書き込めること</li>
</ul>
</li>
<li>(3) :<ul>
<li><code>ForwardIterator1</code>が指す値の型が、<a href="../type_traits/is_move_assignable.html">ムーブ代入可能</a>であり、<code>*first</code>で初期化でき、<code>ForwardIterator2</code>が指す値の型に対して代入できること</li>
<li><code>ForwardIterator1</code>が指す値の型のオブジェクト<code>a</code>と<code>b</code>において、式<code>b - a</code>の結果が、<code>ForwardIterator2</code>が指す値の型に対して代入できること</li>
</ul>
</li>
<li>(4) :<ul>
<li><code>ForwardIterator1</code>が指す値の型が、<a href="../type_traits/is_move_assignable.html">ムーブ代入可能</a>であり、<code>*first</code>で初期化でき、<code>ForwardIterator2</code>が指す値の型に対して代入できること</li>
<li><code>ForwardIterator1</code>が指す値の型のオブジェクト<code>a</code>と<code>b</code>において、式<code>binary_op(b, a)</code>の結果が、<code>ForwardIterator2</code>が指す値の型に対して代入できること</li>
</ul>
</li>
</ul>
<h2>効果</h2>
<ul>
<li>(1), (2) : 非空の<a class="cpprefjp-defined-word" data-desc="2つのイテレータで表現される半開区間を表す。C++20からイテレータと番兵で異なる型であっても指定可能になる">イテレータ範囲</a><code>[first, last)</code>について、<ol>
<li><code>*result = *first</code>で結果の初期値を書き込む。<code>acc = *first</code>としてひとつ前の位置の値を保持する</li>
<li><a class="cpprefjp-defined-word" data-desc="2つのイテレータで表現される半開区間を表す。C++20からイテレータと番兵で異なる型であっても指定可能になる">イテレータ範囲</a><code>[first + 1, last)</code>の各イテレータを<code>i</code>、そのイテレータが指す値を<code>val</code>として定義する
3.<ul>
<li>C++17 : (1)であれば<code>val - acc</code>、(2)であれば<code>binary_op(val, acc)</code>で隣接値を求めて、その結果を<code>*result</code>に代入する</li>
<li>C++20 : (1)であれば<code>val - <a href="../utility/move.html">std::move</a>(acc)</code>、(2)であれば<code>binary_op(val, <a href="../utility/move.html">std::move</a>d(acc))</code>で隣接値を求めて、その結果を<code>*result</code>に代入する</li>
</ul>
</li>
<li><code>val</code>を<code>acc</code>にムーブ代入し、ひとつ前の位置の値を更新する</li>
</ol>
</li>
<li>(3), (4) : 非空の<a class="cpprefjp-defined-word" data-desc="2つのイテレータで表現される半開区間を表す。C++20からイテレータと番兵で異なる型であっても指定可能になる">イテレータ範囲</a><code>[first, last)</code>について、<ol>
<li><code>*result = *first</code>で結果の初期値を代入する</li>
<li>インデックス範囲<code>[1, last - first - 1]</code>のそれぞれの値<code>d</code>として定義する</li>
<li>(3)であれば<code>val = *(first + d) - *(first + d - 1)</code>、(4)であれば<code>val = binary_op(*(first + d), *(first + d - 1))</code>として、隣接値を求める</li>
<li><code>*(result + d) = val</code>で各隣接値を出力する</li>
</ol>
</li>
</ul>
<h2><a class="cpprefjp-defined-word" data-desc="関数呼び出し式の評価結果となるオブジェクト・値">戻り値</a></h2>
<p><div class="codehilite"><pre><span></span><code><span class="n">result</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="p">(</span><span class="n">last</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="n">first</span><span class="p">)</span>
</code></pre></div>
</p>
<h2><a class="cpprefjp-defined-word" data-desc="関数等の意味論を構成する要素の1つ。Complexity。関数が使うアルゴリズムの空間計算量・時間計算量">計算量</a></h2>
<p>ちょうど<code>(last - first) - 1</code>回の2項演算を適用する</p>
<h2>備考</h2>
<ul>
<li>(1), (2) : <code>result</code>は<code>first</code>と同値になるだろう</li>
</ul>
<h2>例</h2>
<p><div class="yata" id="e2c19572467c6008d00435417863ec8296824daa"><div class="codehilite"><pre><span></span><code><span class="cp">#include <a href="../iostream.html"><iostream></a></span>
<span class="cp">#include <a href="../numeric.html"><numeric></a></span>
<span class="cp">#include <a href="../vector.html"><vector></a></span>
<span class="k">template</span><span class="w"> </span><span class="o"><</span><span class="k">class</span><span class="w"> </span><span class="nc">Range</span><span class="o">></span>
<span class="kt">void</span><span class="w"> </span><span class="n">print</span><span class="p">(</span><span class="k">const</span><span class="w"> </span><span class="n">Range</span><span class="o">&</span><span class="w"> </span><span class="n">r</span><span class="p">)</span>
<span class="p">{</span>
<span class="w"> </span><span class="k">for</span><span class="p">(</span><span class="k">const</span><span class="w"> </span><span class="k">auto</span><span class="o">&</span><span class="w"> </span><span class="n">x</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="n">r</span><span class="p">)</span>
<span class="w"> </span><span class="n"><a href="../iostream/cout.html">std::cout</a></span><span class="w"> </span><span class="o"><<</span><span class="w"> </span><span class="n">x</span><span class="w"> </span><span class="o"><<</span><span class="w"> </span><span class="s">" --> "</span><span class="p">;</span>
<span class="w"> </span><span class="n"><a href="../iostream/cout.html">std::cout</a></span><span class="w"> </span><span class="o"><<</span><span class="w"> </span><span class="s">"end"</span><span class="w"> </span><span class="o"><<</span><span class="w"> </span><span class="n"><a href="../ostream/endl.html">std::endl</a></span><span class="p">;</span>
<span class="p">}</span>
<span class="kt">int</span><span class="w"> </span><span class="n">main</span><span class="p">()</span>
<span class="p">{</span>
<span class="w"> </span><span class="n"><a href="../vector/vector.html">std::vector</a></span><span class="o"><</span><span class="kt">double</span><span class="o">></span><span class="w"> </span><span class="n">v</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">{</span><span class="mf">0.0</span><span class="p">,</span><span class="w"> </span><span class="mf">0.2</span><span class="p">,</span><span class="w"> </span><span class="mf">0.4</span><span class="p">,</span><span class="w"> </span><span class="mf">0.6</span><span class="p">,</span><span class="w"> </span><span class="mf">0.8</span><span class="p">};</span>
<span class="w"> </span><span class="n"><a href="../vector/vector.html">std::vector</a></span><span class="o"><</span><span class="kt">double</span><span class="o">></span><span class="w"> </span><span class="n">diffs</span><span class="p">(</span><span class="n"><a href="../vector/vector/size.html">v.size()</a></span><span class="p">);</span>
<span class="w"> </span><span class="c1">// (1) : operator-()を使用して、隣接要素の差を計算する</span>
<span class="w"> </span><span class="n"><span style="color:#ff0000">std::adjacent_difference</span></span><span class="p">(</span><span class="n">v</span><span class="p">.</span><span class="n">cbegin</span><span class="p">(),</span><span class="w"> </span><span class="n">v</span><span class="p">.</span><span class="n">cend</span><span class="p">(),</span><span class="w"> </span><span class="n"><a href="../vector/vector/begin.html">diffs.begin()</a></span><span class="p">);</span>
<span class="w"> </span><span class="n">print</span><span class="p">(</span><span class="n">diffs</span><span class="p">);</span>
<span class="w"> </span><span class="c1">// (2) : 最後の引数として与えた任意の2項演算関数によって、</span>
<span class="w"> </span><span class="c1">// 隣接要素の差を計算する</span>
<span class="w"> </span><span class="n"><span style="color:#ff0000">std::adjacent_difference</span></span><span class="p">(</span><span class="n">v</span><span class="p">.</span><span class="n">cbegin</span><span class="p">(),</span><span class="w"> </span><span class="n">v</span><span class="p">.</span><span class="n">cend</span><span class="p">(),</span><span class="w"> </span><span class="n"><a href="../vector/vector/begin.html">diffs.begin()</a></span><span class="p">,</span>
<span class="w"> </span><span class="p">[](</span><span class="kt">double</span><span class="w"> </span><span class="n">a</span><span class="p">,</span><span class="w"> </span><span class="kt">double</span><span class="w"> </span><span class="n">b</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">a</span><span class="o">*</span><span class="n">a</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="n">b</span><span class="o">*</span><span class="n">b</span><span class="p">;</span><span class="w"> </span><span class="c1">// 2点間の距離の計算</span>
<span class="w"> </span><span class="p">});</span>
<span class="w"> </span><span class="n">print</span><span class="p">(</span><span class="n">diffs</span><span class="p">);</span>
<span class="p">}</span>
</code></pre></div>
</div></p>
<h3>出力</h3>
<p><pre><code>0 --> 0.2 --> 0.2 --> 0.2 --> 0.2 --> end
0 --> 0.04 --> 0.12 --> 0.2 --> 0.28 --> end
</code></pre></p>
<h2>実装例</h2>
<p><div class="codehilite"><pre><span></span><code><span class="cp">#include <a href="../iterator.html"><iterator></a></span>
<span class="cp">#include <a href="../functional.html"><functional></a></span>
<span class="c1">// (2)</span>
<span class="k">template</span><span class="w"> </span><span class="o"><</span><span class="k">class</span><span class="w"> </span><span class="nc">InputIterator</span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">OutputIterator</span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">BinaryOperation</span><span class="o">></span>
<span class="n">OutputIterator</span><span class="w"> </span><span class="n">adjacent_difference</span><span class="p">(</span><span class="n">InputIterator</span><span class="w"> </span><span class="n">first</span><span class="p">,</span>
<span class="w"> </span><span class="n">InputIterator</span><span class="w"> </span><span class="n">last</span><span class="p">,</span>
<span class="w"> </span><span class="n">OutputIterator</span><span class="w"> </span><span class="n">result</span><span class="p">,</span>
<span class="w"> </span><span class="n">BinaryOperation</span><span class="w"> </span><span class="n">binary_op</span><span class="p">)</span>
<span class="p">{</span>
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">first</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="n">last</span><span class="p">)</span>
<span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">result</span><span class="p">;</span>
<span class="w"> </span><span class="k">using</span><span class="w"> </span><span class="n">value_type</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">typename</span><span class="w"> </span><span class="nc"><a href="../iterator/iterator_traits.html">std::iterator_traits</a></span><span class="o"><</span><span class="n">InputIterator</span><span class="o">>::</span><span class="n">value_type</span><span class="p">;</span>
<span class="w"> </span><span class="n">value_type</span><span class="w"> </span><span class="n">acc</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="o">*</span><span class="n">first</span><span class="p">;</span>
<span class="w"> </span><span class="o">*</span><span class="n">result</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">acc</span><span class="p">;</span>
<span class="w"> </span><span class="o">++</span><span class="n">result</span><span class="p">;</span>
<span class="w"> </span><span class="o">++</span><span class="n">first</span><span class="p">;</span>
<span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="n">first</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="n">last</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="n">value_type</span><span class="w"> </span><span class="n">val</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="o">*</span><span class="n">first</span><span class="p">;</span>
<span class="w"> </span><span class="o">*</span><span class="n">result</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">binary_op</span><span class="p">(</span><span class="n">val</span><span class="p">,</span><span class="w"> </span><span class="n"><a href="../utility/move.html">std::move</a></span><span class="p">(</span><span class="n">acc</span><span class="p">));</span>
<span class="w"> </span><span class="n">acc</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n"><a href="../utility/move.html">std::move</a></span><span class="p">(</span><span class="n">val</span><span class="p">);</span>
<span class="w"> </span><span class="o">++</span><span class="n">result</span><span class="p">;</span>
<span class="w"> </span><span class="o">++</span><span class="n">first</span><span class="p">;</span>
<span class="w"> </span><span class="p">}</span>
<span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">result</span><span class="p">;</span>
<span class="p">}</span>
<span class="c1">// (1)</span>
<span class="k">template</span><span class="w"> </span><span class="o"><</span><span class="k">class</span><span class="w"> </span><span class="nc">InputIterator</span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">OutputIterator</span><span class="o">></span>
<span class="n">OutputIterator</span><span class="w"> </span><span class="n">adjacent_difference</span><span class="p">(</span><span class="n">InputIterator</span><span class="w"> </span><span class="n">first</span><span class="p">,</span><span class="w"> </span><span class="n">InputIterator</span><span class="w"> </span><span class="n">last</span><span class="p">,</span><span class="w"> </span><span class="n">OutputIterator</span><span class="w"> </span><span class="n">result</span><span class="p">)</span>
<span class="p">{</span>
<span class="w"> </span><span class="k">using</span><span class="w"> </span><span class="n">value_type</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">typename</span><span class="w"> </span><span class="nc"><a href="../iterator/iterator_traits.html">std::iterator_traits</a></span><span class="o"><</span><span class="n">InputIterator</span><span class="o">>::</span><span class="n">value_type</span><span class="p">;</span>
<span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">adjacent_difference</span><span class="p">(</span><span class="n">first</span><span class="p">,</span><span class="w"> </span><span class="n">last</span><span class="p">,</span><span class="w"> </span><span class="n">result</span><span class="p">,</span><span class="w"> </span><span class="n"><a href="../functional/minus.html">std::minus</a></span><span class="o"><</span><span class="n">value_type</span><span class="o">></span><span class="p">());</span>
<span class="p">}</span>
</code></pre></div>
</p>
<h2>参照</h2>
<ul>
<li><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0467r2.html" target="_blank">P0467R2 Iterator Concerns for Parallel Algorithms</a></li>
<li><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0623r0.html" target="_blank">P0623R0 Final C++17 Parallel Algorithms Fixes</a></li>
<li><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0616r0.pdf" target="_blank">P0616R0 De-pessimize legacy <code><numeric></code> algorithms with <code>std::move</code></a></li>
<li><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2019/p1645r1.html" target="_blank">P1645R1 <code>constexpr</code> for <code><numeric></code> algorithms</a><ul>
<li>C++20で、並列バージョン以外の数値計算アルゴリズムが<code>constexpr</code>対応した</li>
</ul>
</li>
</ul></div>
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