-
Notifications
You must be signed in to change notification settings - Fork 1
Expand file tree
/
Copy pathbasic_istream_view.html
More file actions
503 lines (426 loc) · 37 KB
/
Copy pathbasic_istream_view.html
File metadata and controls
503 lines (426 loc) · 37 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
<!doctype html>
<html class="cpprefjp" lang="ja" itemscope="" itemtype="http://schema.org/WebPage">
<head>
<!-- Google tag (gtag.js) -->
<script async src="https://www.googletagmanager.com/gtag/js?id=G-NXNBNVBTJS"></script>
<script>
window.dataLayer = window.dataLayer || [];
function gtag(){dataLayer.push(arguments);}
gtag('js', new Date());
gtag('config', 'G-NXNBNVBTJS');
</script>
<meta charset="UTF-8">
<title>std::ranges::basic_istream_view - cpprefjp C++日本語リファレンス</title>
<meta name="viewport" content="width=device-width,initial-scale=1">
<meta name="keywords" content="
C++,標準ライブラリ,リファレンス,ドキュメント,STL,std,ranges,std::ranges,class template,cpp20,istream_view,wistream_view
">
<meta name="title" content="std::ranges::basic_istream_view - cpprefjp C++日本語リファレンス" />
<meta itemprop="name" content="std::ranges::basic_istream_view - cpprefjp C++日本語リファレンス" />
<meta property="og:title" content="std::ranges::basic_istream_view - cpprefjp C++日本語リファレンス" />
<meta property="og:url" content="https://cpprefjp.github.io/reference/ranges/basic_istream_view.html" />
<meta property="og:site_name" content="cpprefjp - C++日本語リファレンス" />
<meta property="og:type" content="article" />
<meta property="og:description" content="- (1): 入力ストリームから`Val`型の値を読み取る[`view`](view.md)" />
<meta name="twitter:card" content="summary" />
<meta name="twitter:title" content="std::ranges::basic_istream_view - cpprefjp C++日本語リファレンス" />
<meta name="twitter:url" content="https://cpprefjp.github.io/reference/ranges/basic_istream_view.html" />
<meta name="twitter:description" content="- (1): 入力ストリームから`Val`型の値を読み取る[`view`](view.md)" />
<link rel="alternate" type="application/atom+xml" title="Atom" href="https://cpprefjp.github.io/rss.xml" />
<link rel="apple-touch-icon" sizes="180x180" href="../../static/favicons/apple-touch-icon.png?cachebust=f86c46a60db5ac737e5f16bddeeecab4f10ce6b8">
<link rel="icon" type="image/png" sizes="32x32" href="../../static/favicons/favicon-32x32.png?cachebust=f86c46a60db5ac737e5f16bddeeecab4f10ce6b8">
<link rel="icon" type="image/png" sizes="16x16" href="../../static/favicons/favicon-16x16.png?cachebust=f86c46a60db5ac737e5f16bddeeecab4f10ce6b8">
<link rel="manifest" href="../../manifest.json?cachebust=f86c46a60db5ac737e5f16bddeeecab4f10ce6b8">
<meta name="theme-color" content="#f5f8fc">
<link rel="stylesheet" href="../../static/pygments/default.css?cachebust=f86c46a60db5ac737e5f16bddeeecab4f10ce6b8">
<!-- <link rel="stylesheet" href="../../static/css/root.css"> -->
<link href="../../static/kunai/css/kunai-stage-0.css?cachebust=f86c46a60db5ac737e5f16bddeeecab4f10ce6b8" rel="stylesheet">
<link href="../../static/kunai/css/kunai-stage-1.css?cachebust=f86c46a60db5ac737e5f16bddeeecab4f10ce6b8" rel="stylesheet">
<link href="../../static/kunai/css/kunai-stage-2.css?cachebust=f86c46a60db5ac737e5f16bddeeecab4f10ce6b8" rel="stylesheet">
<link href="../../static/kunai/css/kunai-stage-3.css?cachebust=f86c46a60db5ac737e5f16bddeeecab4f10ce6b8" rel="stylesheet">
<script type="text/javascript" src="../../static/kunai/js/kunai-vendor.js?cachebust=f86c46a60db5ac737e5f16bddeeecab4f10ce6b8"></script>
<script type="text/javascript" src="../../static/kunai/js/kunai.js?cachebust=f86c46a60db5ac737e5f16bddeeecab4f10ce6b8"></script>
<script type="text/javascript">
document.addEventListener('DOMContentLoaded', function() {
var kn = new Kunai;
kn.cpprefjp();
});
</script>
</head>
<body>
<header data-kunai-mdinfo="{"meta": {"header": ["ranges"], "namespace": ["std::ranges"], "id-type": ["class template"], "cpp": ["cpp20"], "alias": ["istream_view,wistream_view"]}, "sources": [{"id": "aae7bb1b6bfe643192eb06c1ab5e313d9599ef25", "source": "#include <ranges>\n#include <sstream>\n#include <iostream>\n\nint main() {\n using namespace std;\n auto iss = istringstream{\"1 2 3 4 5\"};\n\n for (int i : views::istream<int>(iss)) {\n cout << i;\n }\n}\n"}], "page_id": ["reference", "ranges", "basic_istream_view"]}">
<nav class="navbar navbar-default" role="navigation">
<div class="container-fluid">
<div class="navbar-header">
<button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar-collapse">
<span class="sr-only">Toggle navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
</button>
<a class="navbar-brand" href="../../index.html">
<div class="title-wrapper clearfix">
<div class="title">cpprefjp - C++日本語リファレンス</div>
</div>
</a>
</div>
<div class="collapse navbar-collapse" id="navbar-collapse">
<ul class="nav navbar-nav navbar-right">
<li>
<div class="google-search">
<script>
(function() {
var cx = '013316413321391058734:ji_u66hl7hq';
var gcse = document.createElement('script');
gcse.type = 'text/javascript';
gcse.async = true;
gcse.src = (document.location.protocol == 'https:' ? 'https:' : 'http:') +
'//www.google.com/cse/cse.js?cx=' + cx;
var s = document.getElementsByTagName('script')[0];
s.parentNode.insertBefore(gcse, s);
})();
</script>
<div class="gcse-search"></div>
</div>
</li>
<li>
<a href="https://github.com/cpprefjp/site">GitHub Project</a>
</li>
</ul>
</div>
</div>
</nav>
</header>
<main id="main" role="main">
<div class="container-fluid">
<div class="row">
<div class="col-sm-9 col-sm-push-3" itemscope itemtype="http://schema.org/Article">
<div class="row">
<div class="col-sm-12 google-search-result">
<gcse:searchresults></gcse:searchresults>
</div>
</div>
<div class="row">
<div class="col-sm-12 content-header">
<ol class="breadcrumb">
<li itemscope itemtype="http://www.schema.org/SiteNavigationElement">
<span>
<a href="../../index.html" itemprop="url">
<i class="fa fa-fw fa-home"></i>
</a>
</span>
</li>
<li itemscope itemtype="http://www.schema.org/SiteNavigationElement">
<span>
<a href="../../reference.html" itemprop="url">
<span itemprop="name">リファレンス</span>
</a>
</span>
</li>
<li itemscope itemtype="http://www.schema.org/SiteNavigationElement">
<span>
<a href="../../reference/ranges.html" itemprop="url">
<span itemprop="name">ranges</span>
</a>
</span>
</li>
<li class="active" itemscope itemtype="http://www.schema.org/SiteNavigationElement">
<span>
<span itemprop="name">basic_istream_view</span>
</span>
</li>
</ol>
<div class="crsearch"></div>
</div>
</div>
<div class="row">
<div class="col-sm-12 edit-button">
<p class="text-right"><small>
最終更新日時:
<time itemprop="datePublished" class="js-local-time"
datetime="2026-09-11T13:06:31+09:00">
2026年09月11日 13時06分31秒 (JST)
</time>
<br/>
<span itemprop="author" itemscope itemtype="http://schema.org/Person">
<span itemprop="name">Akira Takahashi</span>
</span>
が更新
</small></p>
<script>
(function () {
// 最終更新日時を閲覧者のローカルタイムゾーンで表示し直す (issue #53 の正規化)。
// JS が無効な環境ではサーバ生成の JST 表記がそのまま残る。
function pad(n) { return (n < 10 ? '0' : '') + n; }
var els = document.querySelectorAll('time.js-local-time[datetime]');
for (var i = 0; i < els.length; i++) {
var el = els[i];
var d = new Date(el.getAttribute('datetime'));
if (isNaN(d.getTime())) { continue; }
var tz = '';
try {
var parts = new Intl.DateTimeFormat(undefined, { timeZoneName: 'short' }).formatToParts(d);
for (var j = 0; j < parts.length; j++) {
if (parts[j].type === 'timeZoneName') { tz = parts[j].value; break; }
}
} catch (e) {}
el.textContent = d.getFullYear() + '年' + pad(d.getMonth() + 1) + '月' + pad(d.getDate()) + '日 '
+ pad(d.getHours()) + '時' + pad(d.getMinutes()) + '分' + pad(d.getSeconds()) + '秒'
+ (tz ? ' (' + tz + ')' : '');
}
})();
</script>
<p class="text-right">
<a class="history" target="_blank" href="https://github.com/cpprefjp/site/commits/master/reference/ranges/basic_istream_view.md">
<span class="fa fa-fw fa-clock-o fa-flip-horizontal"></span>履歴
</a>
<a class="edit" target="_blank" href="https://github.com/cpprefjp/site/edit/master/reference/ranges/basic_istream_view.md">
<span class="fa fa-fw fa-pencil"></span>編集
</a>
</p>
</div>
</div>
<div class="row">
<div class="col-sm-12 content-body">
<div class="identifier-type">class template</div><div class="header"><ranges></div><h1 itemprop="name"><span class="namespace" title="namespace std::ranges">std::ranges::</span><span class="token">basic_istream_view</span><span class="cpp cpp20" title="C++20で追加">(C++20)</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="o">::</span><span class="nn">ranges</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="c1">// (1)</span>
<span class="w"> </span><span class="k">template</span><span class="o"><</span><span class="n"><a href="../concepts/movable.html">movable</a></span><span class="w"> </span><span class="n">Val</span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">CharT</span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">Traits</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">char_traits</span><span class="o"><</span><span class="n">CharT</span><span class="o">>></span>
<span class="w"> </span><span class="k">requires</span><span class="w"> </span><span class="n"><a href="../concepts/default_initializable.html">default_initializable</a></span><span class="o"><</span><span class="n">Val</span><span class="o">></span><span class="w"> </span><span class="o">&&</span><span class="w"> </span><span class="n"><i>stream-extractable</i></span><span class="o"><</span><span class="n">Val</span><span class="p">,</span><span class="w"> </span><span class="n">CharT</span><span class="p">,</span><span class="w"> </span><span class="n">Traits</span><span class="o">></span>
<span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">basic_istream_view</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="n"><a href="view_interface.html">view_interface</a></span><span class="o"><</span><span class="n">basic_istream_view</span><span class="o"><</span><span class="n">Val</span><span class="p">,</span><span class="w"> </span><span class="n">CharT</span><span class="p">,</span><span class="w"> </span><span class="n">Traits</span><span class="o">>></span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="err">……</span><span class="w"> </span><span class="p">};</span>
<span class="w"> </span><span class="c1">// (2)</span>
<span class="w"> </span><span class="k">template</span><span class="o"><</span><span class="k">class</span><span class="w"> </span><span class="nc">Val</span><span class="o">></span>
<span class="w"> </span><span class="k">using</span><span class="w"> </span><span class="n">istream_view</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">basic_istream_view</span><span class="o"><</span><span class="n">Val</span><span class="p">,</span><span class="w"> </span><span class="kt">char</span><span class="o">></span><span class="p">;</span>
<span class="w"> </span><span class="c1">// (3)</span>
<span class="w"> </span><span class="k">template</span><span class="o"><</span><span class="k">class</span><span class="w"> </span><span class="nc">Val</span><span class="o">></span>
<span class="w"> </span><span class="k">using</span><span class="w"> </span><span class="n">wistream_view</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">basic_istream_view</span><span class="o"><</span><span class="n">Val</span><span class="p">,</span><span class="w"> </span><span class="kt">wchar_t</span><span class="o">></span><span class="p">;</span>
<span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">views</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="c1">// (4)</span>
<span class="w"> </span><span class="k">template</span><span class="o"><</span><span class="k">class</span><span class="w"> </span><span class="nc">T</span><span class="o">></span>
<span class="w"> </span><span class="kr">inline</span><span class="w"> </span><span class="k">constexpr</span><span class="w"> </span><span class="cm">/*unspecified*/</span><span class="w"> </span><span class="n">istream</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="cm">/*unspecified*/</span><span class="p">;</span>
<span class="w"> </span><span class="p">}</span>
<span class="p">}</span>
</code></pre></div>
</p>
<h2>概要</h2>
<ul>
<li>(1): 入力ストリームから<code>Val</code>型の値を読み取る<code><a href="view.html">view</a></code></li>
<li>(2): <code>basic_istream_view</code>の、文字の型を<code>char</code>とするエイリアス</li>
<li>(2): <code>basic_istream_view</code>の、文字の型を<code>wchar_t</code>とするエイリアス</li>
<li>(4): <code>basic_istream_view</code>を生成する<a class="cpprefjp-defined-word" data-desc="プログラム定義型に対するオーバーロードが許されている標準関数名について、中でいい感じにオーバーロード解決して呼び出してくれる関数オブジェクト">カスタマイゼーションポイントオブジェクト</a></li>
</ul>
<p>基本的な挙動は<code><a href="../iterator/istream_iterator.html">istream_iterator</a></code>と同じで、イテレータが作られるときにストリームから値を1つ読み、インクリメントされるときに次の値を読む。
ただし、<code>basic_istream_view</code>の場合、読んだ値はイテレータではなくRangeオブジェクトに保存されている。</p>
<h3>Rangeコンセプト</h3>
<table border="1" bordercolor="#888" style="border-collapse:collapse">
<thead>
<tr>
<th>borrowed</th>
<th>sized</th>
<th>output</th>
<th>input</th>
<th>forward</th>
<th>bidirectional</th>
<th>random_access</th>
<th>contiguous</th>
<th>common</th>
<th>viewable</th>
<th>view</th>
</tr>
</thead>
<tbody>
<tr>
<td></td>
<td></td>
<td></td>
<td>○</td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td>○</td>
<td>○</td>
</tr>
</tbody>
</table>
<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>
<p>説明専用コンセプト<code>stream-extractable</code>を以下のように定義する。</p>
<p><div class="codehilite"><pre><span></span><code><span class="k">template</span><span class="o"><</span><span class="k">class</span><span class="w"> </span><span class="nc">Val</span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">CharT</span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">Traits</span><span class="o">></span>
<span class="k">concept</span><span class="w"> </span><span class="nc">stream</span><span class="o">-</span><span class="n">extractable</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">requires</span><span class="p">(</span><span class="n">basic_istream</span><span class="o"><</span><span class="n">CharT</span><span class="p">,</span><span class="w"> </span><span class="n">Traits</span><span class="o">>&</span><span class="w"> </span><span class="n">is</span><span class="p">,</span><span class="w"> </span><span class="n">Val</span><span class="o">&</span><span class="w"> </span><span class="n">t</span><span class="p">)</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="n">is</span><span class="w"> </span><span class="o">>></span><span class="w"> </span><span class="n">t</span><span class="p">;</span><span class="w"> </span><span class="p">}</span>
</code></pre></div>
</p>
<p>これを用いて、</p>
<ul>
<li><code><a href="../concepts/movable.html">movable</a><Val></code></li>
<li><code><a href="../concepts/default_initializable.html">default_initializable</a><Val></code></li>
<li><code>stream-extractable<Val, CharT, Traits></code></li>
</ul>
<h2>効果</h2>
<ul>
<li>(4): <code>istream<T>(e)</code>の効果は、<code>U</code>を<code>std::remove_reference_t<decltype(e)></code>とするとき、<code>basic_istream_view<T, typename U::char_type, typename U::traits_type>(e);</code>と等しい。</li>
</ul>
<h2>メンバ関数</h2>
<table border="1" bordercolor="#888" style="border-collapse:collapse">
<thead>
<tr>
<th>名前</th>
<th>説明</th>
<th>対応バージョン</th>
</tr>
</thead>
<tbody>
<tr>
<td><code><a href="basic_istream_view/op_constructor.html">(constructor)</a></code></td>
<td>コンストラクタ</td>
<td>C++20</td>
</tr>
<tr>
<td><code><a href="basic_istream_view/begin.html">begin</a></code></td>
<td>ストリームから値を1つ読み、それを指すイテレータを取得する</td>
<td>C++20</td>
</tr>
<tr>
<td><code><a href="basic_istream_view/end.html">end</a></code></td>
<td>番兵を取得する</td>
<td>C++20</td>
</tr>
</tbody>
</table>
<h2>継承しているメンバ関数</h2>
<table border="1" bordercolor="#888" style="border-collapse:collapse">
<thead>
<tr>
<th>名前</th>
<th>説明</th>
<th>対応バージョン</th>
</tr>
</thead>
<tbody>
<tr>
<td><code><a href="view_interface/cbegin.html">cbegin</a></code></td>
<td>定数イテレータを取得する</td>
<td>C++23</td>
</tr>
<tr>
<td><code><a href="view_interface/cend.html">cend</a></code></td>
<td>定数イテレータ（番兵）を取得する</td>
<td>C++23</td>
</tr>
</tbody>
</table>
<h2>備考</h2>
<p>このクラスは、フリースタンディング処理系では使用できない。</p>
<h2>例</h2>
<p><div class="yata" id="aae7bb1b6bfe643192eb06c1ab5e313d9599ef25"><div class="codehilite"><pre><span></span><code><span class="cp">#include <a href="../ranges.html"><ranges></a></span>
<span class="cp">#include <a href="../sstream.html"><sstream></a></span>
<span class="cp">#include <a href="../iostream.html"><iostream></a></span>
<span class="kt">int</span><span class="w"> </span><span class="nf">main</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="k">using</span><span class="w"> </span><span class="k">namespace</span><span class="w"> </span><span class="nn">std</span><span class="p">;</span>
<span class="w"> </span><span class="k">auto</span><span class="w"> </span><span class="n">iss</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">istringstream</span><span class="p">{</span><span class="s">"1 2 3 4 5"</span><span class="p">};</span>
<span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="n"><span style="color:#ff0000">views::istream</span></span><span class="o"><</span><span class="kt">int</span><span class="o">></span><span class="p">(</span><span class="n">iss</span><span class="p">))</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="n">cout</span><span class="w"> </span><span class="o"><<</span><span class="w"> </span><span class="n">i</span><span class="p">;</span>
<span class="w"> </span><span class="p">}</span>
<span class="p">}</span>
</code></pre></div>
</div></p>
<h3>出力</h3>
<p><pre><code>12345
</code></pre></p>
<h2>実装例</h2>
<p><div class="codehilite"><pre><span></span><code><span class="k">namespace</span><span class="w"> </span><span class="nn">std</span><span class="o">::</span><span class="nn">ranges</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="k">template</span><span class="o"><</span><span class="k">class</span><span class="w"> </span><span class="nc">Val</span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">CharT</span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">Traits</span><span class="o">></span>
<span class="w"> </span><span class="k">concept</span><span class="w"> </span><span class="nc">stream_extractable</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">requires</span><span class="p">(</span><span class="n"><a href="../istream/basic_istream.html">basic_istream</a></span><span class="o"><</span><span class="n">CharT</span><span class="p">,</span><span class="w"> </span><span class="n">Traits</span><span class="o">>&</span><span class="w"> </span><span class="n">is</span><span class="p">,</span><span class="w"> </span><span class="n">Val</span><span class="o">&</span><span class="w"> </span><span class="n">t</span><span class="p">)</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="n">is</span><span class="w"> </span><span class="o">>></span><span class="w"> </span><span class="n">t</span><span class="p">;</span><span class="w"> </span><span class="p">};</span>
<span class="w"> </span><span class="k">template</span><span class="o"><</span><span class="n"><a href="../concepts/movable.html">movable</a></span><span class="w"> </span><span class="n">Val</span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">CharT</span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">Traits</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n"><a href="../string/char_traits.html">char_traits</a></span><span class="o"><</span><span class="n">CharT</span><span class="o">>></span>
<span class="w"> </span><span class="k">requires</span><span class="w"> </span><span class="n"><a href="../concepts/default_initializable.html">default_initializable</a></span><span class="o"><</span><span class="n">Val</span><span class="o">></span><span class="w"> </span><span class="o">&&</span><span class="w"> </span><span class="n">stream_extractable</span><span class="o"><</span><span class="n">Val</span><span class="p">,</span><span class="w"> </span><span class="n">CharT</span><span class="p">,</span><span class="w"> </span><span class="n">Traits</span><span class="o">></span>
<span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">basic_istream_view</span><span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="k">public</span><span class="w"> </span><span class="n"><a href="view_interface.html">view_interface</a></span><span class="o"><</span><span class="n">basic_istream_view</span><span class="o"><</span><span class="n">Val</span><span class="p">,</span><span class="w"> </span><span class="n">CharT</span><span class="p">,</span><span class="w"> </span><span class="n">Traits</span><span class="o">>></span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="k">private</span><span class="o">:</span>
<span class="w"> </span><span class="k">template</span><span class="o"><</span><span class="n"><a href="../concepts/movable.html">movable</a></span><span class="w"> </span><span class="n">Val</span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">CharT</span><span class="p">,</span><span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">Traits</span><span class="o">></span>
<span class="w"> </span><span class="k">requires</span><span class="w"> </span><span class="n"><a href="../concepts/default_initializable.html">default_initializable</a></span><span class="o"><</span><span class="n">Val</span><span class="o">></span><span class="w"> </span><span class="o">&&</span><span class="w"> </span><span class="n">stream_extractable</span><span class="o"><</span><span class="n">Val</span><span class="p">,</span><span class="w"> </span><span class="n">CharT</span><span class="p">,</span><span class="w"> </span><span class="n">Traits</span><span class="o">></span>
<span class="w"> </span><span class="k">class</span><span class="w"> </span><span class="nc">iterator</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="k">public</span><span class="o">:</span>
<span class="w"> </span><span class="k">using</span><span class="w"> </span><span class="n">iterator_concept</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n"><a href="../iterator/iterator_tag.html">input_iterator_tag</a></span><span class="p">;</span>
<span class="w"> </span><span class="k">using</span><span class="w"> </span><span class="n">difference_type</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kt">ptrdiff_t</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="n">Val</span><span class="p">;</span>
<span class="w"> </span><span class="k">constexpr</span><span class="w"> </span><span class="k">explicit</span><span class="w"> </span><span class="n">iterator</span><span class="p">(</span><span class="n">basic_istream_view</span><span class="o">&</span><span class="w"> </span><span class="n">parent</span><span class="p">)</span><span class="w"> </span><span class="k">noexcept</span>
<span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="n">parent_</span><span class="p">(</span><span class="n"><a href="../memory/addressof.html">addressof</a></span><span class="p">(</span><span class="n">parent</span><span class="p">))</span>
<span class="w"> </span><span class="p">{}</span>
<span class="w"> </span><span class="n">iterator</span><span class="p">(</span><span class="k">const</span><span class="w"> </span><span class="n">iterator</span><span class="o">&</span><span class="p">)</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">delete</span><span class="p">;</span>
<span class="w"> </span><span class="n">iterator</span><span class="p">(</span><span class="n">iterator</span><span class="o">&&</span><span class="p">)</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">default</span><span class="p">;</span>
<span class="w"> </span><span class="n">iterator</span><span class="o">&</span><span class="w"> </span><span class="k">operator</span><span class="o">=</span><span class="p">(</span><span class="k">const</span><span class="w"> </span><span class="n">iterator</span><span class="o">&</span><span class="p">)</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">delete</span><span class="p">;</span>
<span class="w"> </span><span class="n">iterator</span><span class="o">&</span><span class="w"> </span><span class="k">operator</span><span class="o">=</span><span class="p">(</span><span class="n">iterator</span><span class="o">&&</span><span class="p">)</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">default</span><span class="p">;</span>
<span class="w"> </span><span class="n">iterator</span><span class="o">&</span><span class="w"> </span><span class="k">operator</span><span class="o">++</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="o">*</span><span class="n">parent_</span><span class="o">-></span><span class="n">stream_</span><span class="w"> </span><span class="o">>></span><span class="w"> </span><span class="n">parent_</span><span class="o">-></span><span class="n">value_</span><span class="p">;</span>
<span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="o">*</span><span class="k">this</span><span class="p">;</span>
<span class="w"> </span><span class="p">}</span>
<span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="k">operator</span><span class="o">++</span><span class="p">(</span><span class="kt">int</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="o">++*</span><span class="k">this</span><span class="p">;</span>
<span class="w"> </span><span class="p">}</span>
<span class="w"> </span><span class="n">Val</span><span class="o">&</span><span class="w"> </span><span class="k">operator</span><span class="o">*</span><span class="p">()</span><span class="w"> </span><span class="k">const</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">parent_</span><span class="o">-></span><span class="n">value_</span><span class="p">;</span>
<span class="w"> </span><span class="p">}</span>
<span class="w"> </span><span class="k">friend</span><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="k">operator</span><span class="o">==</span><span class="p">(</span><span class="k">const</span><span class="w"> </span><span class="n">iterator</span><span class="o">&</span><span class="w"> </span><span class="n">x</span><span class="p">,</span><span class="w"> </span><span class="n"><a href="../iterator/default_sentinel_t.html">default_sentinel_t</a></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="o">!*</span><span class="n">x</span><span class="p">.</span><span class="n">parent_</span><span class="o">-></span><span class="n">stream_</span><span class="p">;</span>
<span class="w"> </span><span class="p">}</span>
<span class="w"> </span><span class="k">private</span><span class="o">:</span>
<span class="w"> </span><span class="n">basic_istream_view</span><span class="o">*</span><span class="w"> </span><span class="n">parent_</span><span class="p">;</span>
<span class="w"> </span><span class="p">};</span>
<span class="w"> </span><span class="k">public</span><span class="o">:</span>
<span class="w"> </span><span class="k">constexpr</span><span class="w"> </span><span class="k">explicit</span><span class="w"> </span><span class="n">basic_istream_view</span><span class="p">(</span><span class="n"><a href="../istream/basic_istream.html">basic_istream</a></span><span class="o"><</span><span class="n">CharT</span><span class="p">,</span><span class="w"> </span><span class="n">Traits</span><span class="o">>&</span><span class="w"> </span><span class="n">stream</span><span class="p">)</span>
<span class="w"> </span><span class="o">:</span><span class="w"> </span><span class="n">stream_</span><span class="p">(</span><span class="n"><a href="../memory/addressof.html">addressof</a></span><span class="p">(</span><span class="n">stream</span><span class="p">))</span>
<span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="p">}</span>
<span class="w"> </span><span class="k">constexpr</span><span class="w"> </span><span class="k">auto</span><span class="w"> </span><span class="n">begin</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="o">*</span><span class="n">stream_</span><span class="w"> </span><span class="o">>></span><span class="w"> </span><span class="n">value_</span><span class="p">;</span>
<span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">iterator</span><span class="p">{</span><span class="o">*</span><span class="k">this</span><span class="p">};</span>
<span class="w"> </span><span class="p">}</span>
<span class="w"> </span><span class="k">constexpr</span><span class="w"> </span><span class="n"><a href="../iterator/default_sentinel_t.html">default_sentinel_t</a></span><span class="w"> </span><span class="n">end</span><span class="p">()</span><span class="w"> </span><span class="k">const</span><span class="w"> </span><span class="k">noexcept</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 href="../iterator/default_sentinel_t.html">default_sentinel</a></span><span class="p">;</span>
<span class="w"> </span><span class="p">}</span>
<span class="w"> </span><span class="k">private</span><span class="o">:</span>
<span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="nc">iterator</span><span class="p">;</span>
<span class="w"> </span><span class="n"><a href="../istream/basic_istream.html">basic_istream</a></span><span class="o"><</span><span class="n">CharT</span><span class="p">,</span><span class="w"> </span><span class="n">Traits</span><span class="o">>*</span><span class="w"> </span><span class="n">stream_</span><span class="p">;</span>
<span class="w"> </span><span class="n">Val</span><span class="w"> </span><span class="n">value_</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">Val</span><span class="p">();</span>
<span class="w"> </span><span class="p">};</span>
<span class="p">}</span>
</code></pre></div>
</p>
<h2>バージョン</h2>
<h3>言語</h3>
<ul>
<li>C++20</li>
</ul>
<h3>処理系</h3>
<ul>
<li><a href="../../implementation.html#clang">Clang</a>: 13.0.0 <span aria-label="検証済" role="img" title="検証済">✅</span></li>
<li><a href="../../implementation.html#gcc">GCC</a>: 10.1.0 <span aria-label="検証済" role="img" title="検証済">✅</span></li>
<li><a href="../../implementation.html#visual_cpp">Visual C++</a>: 2019 Update 10 <span aria-label="検証済" role="img" title="検証済">✅</span></li>
</ul>
<h2>関連項目</h2>
<ul>
<li><code><a href="../iterator/istream_iterator.html">istream_iterator</a></code>: ストリームからデータを読み込む入力イテレータ</li>
</ul>
<h2>参照</h2>
<ul>
<li><a href="https://timsong-cpp.github.io/cppwp/n4861/ranges" target="_blank">N4861 24 Ranges library</a></li>
<li><a href="https://techbookfest.org/product/5134506308665344" target="_blank">C++20 ranges</a></li>
</ul></div>
</div>
</div>
</div>
<div id="sidebar" class="col-sm-3 col-sm-pull-9">
</div>
</div>
</div>
</main>
<footer class="footer navbar navbar-default">
<div class="container-fluid">
<p><small>
本サイトの情報は、
<a href="https://creativecommons.org/licenses/by/4.0/deed.ja" rel="nofollow">クリエイティブ・コモンズ 表示 4.0 非移植 ライセンス(CC BY)</a>
の下に提供されています。
</small></p>
</div>
</footer>
</body>
</html>