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
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
|
<!DOCTYPE html>
<html lang="en" dir="ltr" class="client-nojs">
<head>
<title>Template parameters and template arguments - cppreference.com</title>
<meta charset="UTF-8" />
<meta name="generator" content="MediaWiki 1.21.2" />
<link rel="alternate" type="application/x-wiki" title="Edit" href="http://en.cppreference.com/mwiki/index.php?title=cpp/language/template_parameters&action=edit" />
<link rel="edit" title="Edit" href="http://en.cppreference.com/mwiki/index.php?title=cpp/language/template_parameters&action=edit" />
<link rel="shortcut icon" href="../../../favicon.ico" />
<link rel="search" type="application/opensearchdescription+xml" href="../../../mwiki/opensearch_desc.php" title="cppreference.com (en)" />
<link rel="EditURI" type="application/rsd+xml" href="http://en.cppreference.com/mwiki/api.php?action=rsd" />
<link rel="alternate" type="application/atom+xml" title="cppreference.com Atom feed" href="http://en.cppreference.com/mwiki/index.php?title=Special:RecentChanges&feed=atom" />
<link rel="stylesheet" href="../../../mwiki/load.php%3Fdebug=false&lang=en&modules=ext.gadget.ColiruCompiler%257Cext.rtlcite%257Cmediawiki.legacy.commonPrint%252Cshared%257Cskins.cppreference2&only=styles&skin=cppreference2&*.css" />
<meta name="ResourceLoaderDynamicStyles" content="" />
<link rel="stylesheet" href="../../../mwiki/load.php%3Fdebug=false&lang=en&modules=site&only=styles&skin=cppreference2&*.css" />
<style>a:lang(ar),a:lang(ckb),a:lang(fa),a:lang(kk-arab),a:lang(mzn),a:lang(ps),a:lang(ur){text-decoration:none}#toc{display:none}.editsection{display:none}
/* cache key: mwiki1-mwiki_en_:resourceloader:filter:minify-css:7:472787eddcf4605d11de8c7ef047234f */</style>
<script src="../../../mwiki/load.php%3Fdebug=false&lang=en&modules=startup&only=scripts&skin=cppreference2&*"></script>
<script>if(window.mw){
mw.config.set({"wgCanonicalNamespace":"","wgCanonicalSpecialPageName":false,"wgNamespaceNumber":0,"wgPageName":"cpp/language/template_parameters","wgTitle":"cpp/language/template parameters","wgCurRevisionId":81843,"wgArticleId":13162,"wgIsArticle":true,"wgAction":"view","wgUserName":null,"wgUserGroups":["*"],"wgCategories":["Todo with reason"],"wgBreakFrames":false,"wgPageContentLanguage":"en","wgSeparatorTransformTable":["",""],"wgDigitTransformTable":["",""],"wgDefaultDateFormat":"dmy","wgMonthNames":["","January","February","March","April","May","June","July","August","September","October","November","December"],"wgMonthNamesShort":["","Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"],"wgRelevantPageName":"cpp/language/template_parameters","wgRestrictionEdit":[],"wgRestrictionMove":[]});
}</script><script>if(window.mw){
mw.loader.implement("user.options",function(){mw.user.options.set({"ccmeonemails":0,"cols":80,"date":"default","diffonly":0,"disablemail":0,"disablesuggest":0,"editfont":"default","editondblclick":0,"editsection":0,"editsectiononrightclick":0,"enotifminoredits":0,"enotifrevealaddr":0,"enotifusertalkpages":1,"enotifwatchlistpages":0,"extendwatchlist":0,"externaldiff":0,"externaleditor":0,"fancysig":0,"forceeditsummary":0,"gender":"unknown","hideminor":0,"hidepatrolled":0,"imagesize":2,"justify":0,"math":1,"minordefault":0,"newpageshidepatrolled":0,"nocache":0,"noconvertlink":0,"norollbackdiff":0,"numberheadings":0,"previewonfirst":0,"previewontop":1,"quickbar":5,"rcdays":7,"rclimit":50,"rememberpassword":0,"rows":25,"searchlimit":20,"showhiddencats":0,"showjumplinks":1,"shownumberswatching":1,"showtoc":0,"showtoolbar":1,"skin":"cppreference2","stubthreshold":0,"thumbsize":2,"underline":2,"uselivepreview":0,"usenewrc":0,"watchcreations":0,"watchdefault":0,"watchdeletion":0,
"watchlistdays":3,"watchlisthideanons":0,"watchlisthidebots":0,"watchlisthideliu":0,"watchlisthideminor":0,"watchlisthideown":0,"watchlisthidepatrolled":0,"watchmoves":0,"wllimit":250,"variant":"en","language":"en","searchNs0":true,"searchNs1":false,"searchNs2":false,"searchNs3":false,"searchNs4":false,"searchNs5":false,"searchNs6":false,"searchNs7":false,"searchNs8":false,"searchNs9":false,"searchNs10":false,"searchNs11":false,"searchNs12":false,"searchNs13":false,"searchNs14":false,"searchNs15":false,"gadget-ColiruCompiler":1});;},{},{});mw.loader.implement("user.tokens",function(){mw.user.tokens.set({"editToken":"+\\","patrolToken":false,"watchToken":false});;},{},{});
/* cache key: mwiki1-mwiki_en_:resourceloader:filter:minify-js:7:ca03345b1e2c4d90a25d968753a73b92 */
}</script>
<script>if(window.mw){
mw.loader.load(["mediawiki.page.startup","mediawiki.legacy.wikibits","mediawiki.legacy.ajax"]);
}</script>
<style type="text/css">/*<![CDATA[*/
.source-cpp {line-height: normal;}
.source-cpp li, .source-cpp pre {
line-height: normal; border: 0px none white;
}
/**
* GeSHi Dynamically Generated Stylesheet
* --------------------------------------
* Dynamically generated stylesheet for cpp
* CSS class: source-cpp, CSS id:
* GeSHi (C) 2004 - 2007 Nigel McNie, 2007 - 2008 Benny Baumann
* (http://qbnz.com/highlighter/ and http://geshi.org/)
* --------------------------------------
*/
.cpp.source-cpp .de1, .cpp.source-cpp .de2 {font: normal normal 1em/1.2em monospace; margin:0; padding:0; background:none; vertical-align:top;}
.cpp.source-cpp {font-family:monospace;}
.cpp.source-cpp .imp {font-weight: bold; color: red;}
.cpp.source-cpp li, .cpp.source-cpp .li1 {font-weight: normal; vertical-align:top;}
.cpp.source-cpp .ln {width:1px;text-align:right;margin:0;padding:0 2px;vertical-align:top;}
.cpp.source-cpp .li2 {font-weight: bold; vertical-align:top;}
.cpp.source-cpp .kw1 {color: #0000dd;}
.cpp.source-cpp .kw2 {color: #0000ff;}
.cpp.source-cpp .kw3 {color: #0000dd;}
.cpp.source-cpp .kw4 {color: #0000ff;}
.cpp.source-cpp .co1 {color: #909090;}
.cpp.source-cpp .co2 {color: #339900;}
.cpp.source-cpp .coMULTI {color: #ff0000; font-style: italic;}
.cpp.source-cpp .es0 {color: #008000; font-weight: bold;}
.cpp.source-cpp .es1 {color: #008000; font-weight: bold;}
.cpp.source-cpp .es2 {color: #008000; font-weight: bold;}
.cpp.source-cpp .es3 {color: #008000; font-weight: bold;}
.cpp.source-cpp .es4 {color: #008000; font-weight: bold;}
.cpp.source-cpp .es5 {color: #008000; font-weight: bold;}
.cpp.source-cpp .br0 {color: #008000;}
.cpp.source-cpp .sy0 {color: #008000;}
.cpp.source-cpp .sy1 {color: #000080;}
.cpp.source-cpp .sy2 {color: #000040;}
.cpp.source-cpp .sy3 {color: #000040;}
.cpp.source-cpp .sy4 {color: #008080;}
.cpp.source-cpp .st0 {color: #008000;}
.cpp.source-cpp .nu0 {color: #000080;}
.cpp.source-cpp .nu6 {color: #000080;}
.cpp.source-cpp .nu8 {color: #000080;}
.cpp.source-cpp .nu12 {color: #000080;}
.cpp.source-cpp .nu16 {color:#000080;}
.cpp.source-cpp .nu17 {color:#000080;}
.cpp.source-cpp .nu18 {color:#000080;}
.cpp.source-cpp .nu19 {color:#000080;}
.cpp.source-cpp .ln-xtra, .cpp.source-cpp li.ln-xtra, .cpp.source-cpp div.ln-xtra {background-color: #ffc;}
.cpp.source-cpp span.xtra { display:block; }
/*]]>*/
</style><style type="text/css">/*<![CDATA[*/
.source-text {line-height: normal;}
.source-text li, .source-text pre {
line-height: normal; border: 0px none white;
}
/**
* GeSHi Dynamically Generated Stylesheet
* --------------------------------------
* Dynamically generated stylesheet for text
* CSS class: source-text, CSS id:
* GeSHi (C) 2004 - 2007 Nigel McNie, 2007 - 2008 Benny Baumann
* (http://qbnz.com/highlighter/ and http://geshi.org/)
* --------------------------------------
*/
.text.source-text .de1, .text.source-text .de2 {font: normal normal 1em/1.2em monospace; margin:0; padding:0; background:none; vertical-align:top;}
.text.source-text {font-family:monospace;}
.text.source-text .imp {font-weight: bold; color: red;}
.text.source-text li, .text.source-text .li1 {font-weight: normal; vertical-align:top;}
.text.source-text .ln {width:1px;text-align:right;margin:0;padding:0 2px;vertical-align:top;}
.text.source-text .li2 {font-weight: bold; vertical-align:top;}
.text.source-text .ln-xtra, .text.source-text li.ln-xtra, .text.source-text div.ln-xtra {background-color: #ffc;}
.text.source-text span.xtra { display:block; }
/*]]>*/
</style><!--[if lt IE 7]><style type="text/css">body{behavior:url("/mwiki/skins/cppreference2/csshover.min.htc")}</style><![endif]--></head>
<body class="mediawiki ltr sitedir-ltr ns-0 ns-subject page-cpp_language_template_parameters skin-cppreference2 action-view cpp-navbar">
<!-- header -->
<div id="mw-head" class="noprint">
<div id="cpp-head-first-base">
<div id="cpp-head-first">
<h5><a href="../../../index.html">
cppreference.com </a></h5>
<div id="cpp-head-search">
<!-- 0 -->
<div id="p-search">
<h5><label for="searchInput">Search</label></h5>
<form action="http://en.cppreference.com/mwiki/index.php" id="searchform">
<input type='hidden' name="title" value="Special:Search"/>
<div id="simpleSearch">
<input name="search" title="Search cppreference.com [f]" accesskey="f" id="searchInput" /> <button type="submit" name="button" title="Search the pages for this text" id="searchButton"><img src="../../../mwiki/skins/cppreference2/images/search-ltr.png%3F303" alt="Search" /></button> </div>
</form>
</div>
<!-- /0 -->
</div>
<div id="cpp-head-personal">
<!-- 0 -->
<div id="p-personal" class="">
<span id="pt-createaccount"><a href="http://en.cppreference.com/mwiki/index.php?title=Special:UserLogin&returnto=cpp%2Flanguage%2Ftemplate+parameters&type=signup">Create account</a></span> <div class="menu">
<ul>
<li id="pt-login"><a href="http://en.cppreference.com/mwiki/index.php?title=Special:UserLogin&returnto=cpp%2Flanguage%2Ftemplate+parameters" title="You are encouraged to log in; however, it is not mandatory [o]" accesskey="o">Log in</a></li> </ul>
</div>
</div>
<!-- /0 -->
</div>
</div>
</div>
<div id="cpp-head-second-base">
<div id="cpp-head-second">
<div id="cpp-head-tools-left">
<!-- 0 -->
<div id="p-namespaces" class="vectorTabs">
<h5>Namespaces</h5>
<ul>
<li id="ca-nstab-main" class="selected"><span><a href="template_parameters.html" title="View the content page [c]" accesskey="c">Page</a></span></li>
<li id="ca-talk" class="new"><span><a href="http://en.cppreference.com/mwiki/index.php?title=Talk:cpp/language/template_parameters&action=edit&redlink=1" title="Discussion about the content page [t]" accesskey="t">Discussion</a></span></li>
</ul>
</div>
<!-- /0 -->
<!-- 1 -->
<div id="p-variants" class="vectorMenu emptyPortlet">
<h5><span>Variants</span><a href="template_parameters.html#"></a></h5>
<div class="menu">
<ul>
</ul>
</div>
</div>
<!-- /1 -->
</div>
<div id="cpp-head-tools-right">
<!-- 0 -->
<div id="p-views" class="vectorTabs">
<h5>Views</h5>
<ul>
<li id="ca-view" class="selected"><span><a href="template_parameters.html" >View</a></span></li>
<li id="ca-edit"><span><a href="http://en.cppreference.com/mwiki/index.php?title=cpp/language/template_parameters&action=edit" title="You can edit this page. Please use the preview button before saving [e]" accesskey="e">Edit</a></span></li>
<li id="ca-history" class="collapsible"><span><a href="http://en.cppreference.com/mwiki/index.php?title=cpp/language/template_parameters&action=history" title="Past revisions of this page [h]" accesskey="h">History</a></span></li>
</ul>
</div>
<!-- /0 -->
<!-- 1 -->
<div id="p-cactions" class="vectorMenu emptyPortlet">
<h5><span>Actions</span><a href="template_parameters.html#"></a></h5>
<div class="menu">
<ul>
</ul>
</div>
</div>
<!-- /1 -->
</div>
</div>
</div>
</div>
<!-- /header -->
<!-- content -->
<div id="cpp-content-base">
<div id="content">
<a id="top"></a>
<div id="mw-js-message" style="display:none;"></div>
<!-- firstHeading -->
<h1 id="firstHeading" class="firstHeading">Template parameters and template arguments</h1>
<!-- /firstHeading -->
<!-- bodyContent -->
<div id="bodyContent">
<!-- tagline -->
<div id="siteSub">From cppreference.com</div>
<!-- /tagline -->
<!-- subtitle -->
<div id="contentSub"><span class="subpages">< <a href="../../cpp.html" title="cpp">cpp</a>‎ | <a href="../language.1.html" title="cpp/language">language</a></span></div>
<!-- /subtitle -->
<!-- bodycontent -->
<div id="mw-content-text" lang="en" dir="ltr" class="mw-content-ltr"><div class="t-navbar" style=""><div class="t-navbar-sep"> </div><div class="t-navbar-head"><a href="../../cpp.html" title="cpp"> C++</a><div class="t-navbar-menu"><div><div><table class="t-nv-begin" cellpadding="0" style="line-height:1.1em;">
<tr class="t-nv"><td colspan="5"> <a href="../language.1.html" title="cpp/language"> Language</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../header.html" title="cpp/header"> Standard library headers</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../concept.html" title="cpp/concept"> Concepts</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../utility.html" title="cpp/utility"> Utilities library</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../string.html" title="cpp/string"> Strings library</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../container.html" title="cpp/container"> Containers library</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../algorithm.html" title="cpp/algorithm"> Algorithms library</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../iterator.html" title="cpp/iterator"> Iterators library</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../numeric.html" title="cpp/numeric"> Numerics library</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../io.html" title="cpp/io"> Input/output library</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../locale.html" title="cpp/locale"> Localizations library</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../regex.html" title="cpp/regex"> Regular expressions library</a> <span class="t-mark-rev t-since-cxx11">(C++11)</span> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../atomic.html" title="cpp/atomic"> Atomic operations library</a> <span class="t-mark-rev t-since-cxx11">(C++11)</span> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../thread.html" title="cpp/thread"> Thread support library</a> <span class="t-mark-rev t-since-cxx11">(C++11)</span> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../experimental.html" title="cpp/experimental"> Technical Specifications</a> </td></tr>
</table></div><div><span class="editsection noprint plainlinks" title="Edit this template"><a rel="nofollow" class="external text" href="http://en.cppreference.com/mwiki/index.php?title=Template:cpp/navbar_content&action=edit">[edit]</a></span></div></div></div></div><div class="t-navbar-sep"> </div><div class="t-navbar-head"><a href="../language.1.html" title="cpp/language"> C++ language</a></div><div class="t-navbar-sep"> </div><div class="t-navbar-head"><a href="templates.html" title="cpp/language/templates"> Templates</a><div class="t-navbar-menu"><div><div style="display:inline-block">
<div><table class="t-nv-begin" cellpadding="0" style="">
<tr class="t-nv"><td colspan="5"> <strong class="selflink"> parameters and arguments</strong> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="class_template.html" title="cpp/language/class template"> class templates</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="function_template.html" title="cpp/language/function template"> function templates</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="member_template.html" title="cpp/language/member template"> class member templates</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="variable_template.html" title="cpp/language/variable template"> variable templates</a><span class="t-mark-rev t-since-cxx14">(C++14)</span></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="template_argument_deduction.html" title="cpp/language/template argument deduction"> template argument deduction</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="template_specialization.html" title="cpp/language/template specialization"> explicit (full) specialization</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="partial_specialization.html" title="cpp/language/partial specialization"> partial specialization</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="dependent_name.html" title="cpp/language/dependent name"> dependent names</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="parameter_pack.html" title="cpp/language/parameter pack"> parameter packs</a><span class="t-mark-rev t-since-cxx11">(C++11)</span></td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="sizeof....html" title="cpp/language/sizeof..."><span class="t-lines"><span>sizeof...</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-cxx11">(C++11)</span></span></span></div></div></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="fold.html" title="cpp/language/fold"> fold-expressions</a><span class="t-mark-rev t-since-cxx17">(C++17)</span></td></tr>
<tr class="t-nv"><td colspan="5"> <a href="sfinae.html" title="cpp/language/sfinae"> SFINAE</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="concepts.html" title="cpp/language/constraints"> Constraints and concepts</a><span class="t-mark-rev t-since-concepts-ts t-mark-ts">(concepts TS)</span> </td></tr>
</table></div>
</div><div><span class="editsection noprint plainlinks" title="Edit this template"><a rel="nofollow" class="external text" href="http://en.cppreference.com/mwiki/index.php?title=Template:cpp/language/templates/navbar_content&action=edit">[edit]</a></span></div></div></div></div><div class="t-navbar-sep"> </div></div>
<p>Every <a href="templates.html" title="cpp/language/templates">template</a> is parametrized by one or more template parameters, indicated in the <span class="t-spar">parameter-list</span> of the template declaration syntax:
</p>
<table class="t-sdsc-begin">
<tr>
<td colspan="10" class="t-sdsc-sep">
</td></tr>
<tr class="t-sdsc">
<td> <code><b>template</b></code> <code><b><</b></code> <span class="t-spar">parameter-list</span> <code><b>></b></code> <span class="t-spar">declaration</span>
</td>
<td> (1)
</td>
<td class="t-sdsc-nopad">
</td></tr>
<tr>
<td colspan="10" class="t-sdsc-sep">
</td></tr></table>
<p>Each parameter in <span class="t-spar">parameter-list</span> may be:
</p>
<ul><li> a non-type template parameter;
</li><li> a type template parameter;
</li><li> a template template parameter.
</li></ul>
<table id="toc" class="toc"><tr><td><div id="toctitle"><h2>Contents</h2></div>
<ul>
<li class="toclevel-1 tocsection-1"><a href="template_parameters.html#Non-type_template_parameter"><span class="tocnumber">1</span> <span class="toctext">Non-type template parameter</span></a></li>
<li class="toclevel-1 tocsection-2"><a href="template_parameters.html#Type_template_parameter"><span class="tocnumber">2</span> <span class="toctext">Type template parameter</span></a></li>
<li class="toclevel-1 tocsection-3"><a href="template_parameters.html#Template_template_parameter"><span class="tocnumber">3</span> <span class="toctext">Template template parameter</span></a></li>
<li class="toclevel-1 tocsection-4"><a href="template_parameters.html#Template_arguments"><span class="tocnumber">4</span> <span class="toctext">Template arguments</span></a>
<ul>
<li class="toclevel-2 tocsection-5"><a href="template_parameters.html#Template_non-type_arguments"><span class="tocnumber">4.1</span> <span class="toctext">Template non-type arguments</span></a></li>
<li class="toclevel-2 tocsection-6"><a href="template_parameters.html#Template_type_arguments"><span class="tocnumber">4.2</span> <span class="toctext">Template type arguments</span></a></li>
<li class="toclevel-2 tocsection-7"><a href="template_parameters.html#Template_template_arguments"><span class="tocnumber">4.3</span> <span class="toctext">Template template arguments</span></a></li>
<li class="toclevel-2 tocsection-8"><a href="template_parameters.html#Default_template_arguments"><span class="tocnumber">4.4</span> <span class="toctext">Default template arguments</span></a></li>
</ul>
</li>
<li class="toclevel-1 tocsection-9"><a href="template_parameters.html#Examples"><span class="tocnumber">5</span> <span class="toctext">Examples</span></a>
<ul>
<li class="toclevel-2 tocsection-10"><a href="template_parameters.html#Non-type_template_parameters"><span class="tocnumber">5.1</span> <span class="toctext">Non-type template parameters</span></a></li>
</ul>
</li>
</ul>
</td></tr></table>
<h4><span class="editsection">[<a href="http://en.cppreference.com/mwiki/index.php?title=cpp/language/template_parameters&action=edit&section=1" title="Edit section: Non-type template parameter">edit</a>]</span> <span class="mw-headline" id="Non-type_template_parameter">Non-type template parameter</span></h4>
<table class="t-sdsc-begin">
<tr>
<td colspan="10" class="t-sdsc-sep">
</td></tr>
<tr class="t-sdsc">
<td> <span class="t-spar">type</span> <span class="t-spar">name</span><span class="t-mark">(optional)</span>
</td>
<td> (1)
</td>
<td class="t-sdsc-nopad">
</td></tr>
<tr>
<td colspan="10" class="t-sdsc-sep">
</td></tr>
<tr class="t-sdsc">
<td> <span class="t-spar">type</span> <span class="t-spar">name</span><span class="t-mark">(optional)</span> <code><b>= </b></code> <span class="t-spar">default</span>
</td>
<td> (2)
</td>
<td class="t-sdsc-nopad">
</td></tr>
<tr>
<td colspan="10" class="t-sdsc-sep">
</td></tr>
<tr class="t-sdsc">
<td> <span class="t-spar">type</span> <code><b>...</b></code> <span class="t-spar">name</span><span class="t-mark">(optional)</span>
</td>
<td> (3)
</td>
<td> <span class="t-mark-rev t-since-cxx11">(since C++11)</span>
</td></tr>
<tr>
<td colspan="10" class="t-sdsc-sep">
</td></tr></table>
<div class="t-li1"><span class="t-li">1)</span> A non-type template parameter with an optional name.</div>
<div class="t-li1"><span class="t-li">2)</span> A non-type template parameter with an optional name and a default value.</div>
<div class="t-li1"><span class="t-li">3)</span> A non-type template <a href="parameter_pack.html" title="cpp/language/parameter pack">parameter pack</a> with an optional name.</div>
<p><span class="t-spar">type</span> is one of the following types (optionally cv-qualified, the qualifiers are ignored):
</p>
<ul><li> <span class="t-lc"><a href="../types/nullptr_t.html" title="cpp/types/nullptr t">std::nullptr_t</a></span> <span class="t-mark-rev t-since-cxx11">(since C++11)</span>;
</li><li> <a href="type-id.html" title="cpp/language/type">integral type</a>;
</li><li> <a href="reference.html#lvalue_references" title="cpp/language/reference">lvalue reference type</a> (to object or to function);
</li><li> <a href="pointer.html" title="cpp/language/pointer">pointer type</a> (to object or to function);
</li><li> <a href="pointer.html#pointers_to_data_members" title="cpp/language/pointer">pointer to member type</a> (to member object or to member function);
</li><li> <a href="enum.html" title="cpp/language/enum">enumeration type</a>.
</li></ul>
<p>Array and function types may be written in a template declaration, but they are automatically replaced by pointer to object and pointer to function as appropriate.
</p><p>When the name of a non-type template parameter is used in an expression within the body of the class template, it is an unmodifiable <a href="value_category.html" title="cpp/language/value category">prvalue</a> unless its type was an lvalue reference type.
</p><p>A template parameter of the form <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw1">class</span> Foo</span></span> is not an unnamed non-type template parameter of type <code>Foo</code>, even if otherwise <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw1">class</span> Foo</span></span> is an <a href="elaborated_type_specifier.html" title="cpp/language/elaborated type specifier">elaborated type specifier</a> and <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="kw1">class</span> Foo x<span class="sy4">;</span></span></span> declares <code>x</code> to be of type <code>Foo</code>.
</p>
<h4><span class="editsection">[<a href="http://en.cppreference.com/mwiki/index.php?title=cpp/language/template_parameters&action=edit&section=2" title="Edit section: Type template parameter">edit</a>]</span> <span class="mw-headline" id="Type_template_parameter">Type template parameter</span></h4>
<table class="t-sdsc-begin">
<tr>
<td colspan="10" class="t-sdsc-sep">
</td></tr>
<tr class="t-sdsc">
<td> <code><b>typename</b></code> <span class="t-spar">name</span><span class="t-mark">(optional)</span>
</td>
<td> (1)
</td>
<td class="t-sdsc-nopad">
</td></tr>
<tr>
<td colspan="10" class="t-sdsc-sep">
</td></tr>
<tr class="t-sdsc">
<td> <code><b>class</b></code> <span class="t-spar">name</span><span class="t-mark">(optional)</span>
</td>
<td> (2)
</td>
<td class="t-sdsc-nopad">
</td></tr>
<tr>
<td colspan="10" class="t-sdsc-sep">
</td></tr>
<tr class="t-sdsc">
<td> <code><b>typename|class</b></code> <span class="t-spar">name</span><span class="t-mark">(optional)</span> <code><b>= </b></code> <span class="t-spar">default</span>
</td>
<td> (3)
</td>
<td class="t-sdsc-nopad">
</td></tr>
<tr>
<td colspan="10" class="t-sdsc-sep">
</td></tr>
<tr class="t-sdsc">
<td> <code><b>typename|class</b></code> <code><b>...</b></code> <span class="t-spar">name</span><span class="t-mark">(optional)</span>
</td>
<td> (4)
</td>
<td> <span class="t-mark-rev t-since-cxx11">(since C++11)</span>
</td></tr>
<tr>
<td colspan="10" class="t-sdsc-sep">
</td></tr></table>
<div class="t-li1"><span class="t-li">1)</span> A type template parameter with an optional name.</div>
<div class="t-li1"><span class="t-li">2)</span> Exactly the same as 1).</div>
<div class="t-li1"><span class="t-li">3)</span> A type template parameter with an optional name and a default.</div>
<div class="t-li1"><span class="t-li">4)</span> A type template <a href="parameter_pack.html" title="cpp/language/parameter pack">parameter pack</a> with an optional name.</div>
<p>In the body of the template declaration, the name of a type parameter is a typedef-name which aliases the type supplied when the template is instantiated.
</p><p>There is no difference between the keywords <code><b>class</b></code> and <code><b>typename</b></code> in a type template parameter declaration.
</p>
<h4><span class="editsection">[<a href="http://en.cppreference.com/mwiki/index.php?title=cpp/language/template_parameters&action=edit&section=3" title="Edit section: Template template parameter">edit</a>]</span> <span class="mw-headline" id="Template_template_parameter">Template template parameter</span></h4>
<table class="t-sdsc-begin">
<tr>
<td colspan="10" class="t-sdsc-sep">
</td></tr>
<tr class="t-sdsc">
<td> <code><b>template</b></code> <code><b><</b></code> <span class="t-spar">parameter-list</span> <code><b>></b></code> <code><b>typename<span class="t-mark-rev t-since-cxx17">(C++17)</span>|class</b></code> <span class="t-spar">name</span><span class="t-mark">(optional)</span>
</td>
<td> (1)
</td>
<td class="t-sdsc-nopad">
</td></tr>
<tr>
<td colspan="10" class="t-sdsc-sep">
</td></tr>
<tr class="t-sdsc">
<td> <code><b>template</b></code> <code><b><</b></code> <span class="t-spar">parameter-list</span> <code><b>></b></code> <code><b>typename<span class="t-mark-rev t-since-cxx17">(C++17)</span>|class</b></code> <span class="t-spar">name</span><span class="t-mark">(optional)</span> <code><b>=</b></code> <span class="t-spar">default</span>
</td>
<td> (2)
</td>
<td class="t-sdsc-nopad">
</td></tr>
<tr>
<td colspan="10" class="t-sdsc-sep">
</td></tr>
<tr class="t-sdsc">
<td> <code><b>template</b></code> <code><b><</b></code> <span class="t-spar">parameter-list</span> <code><b>></b></code> <code><b>typename<span class="t-mark-rev t-since-cxx17">(C++17)</span>|class</b></code> <code><b>...</b></code> <span class="t-spar">name</span><span class="t-mark">(optional)</span>
</td>
<td> (3)
</td>
<td> <span class="t-mark-rev t-since-cxx11">(since C++11)</span>
</td></tr>
<tr>
<td colspan="10" class="t-sdsc-sep">
</td></tr></table>
<div class="t-li1"><span class="t-li">1)</span> A template template parameter with an optional name.</div>
<div class="t-li1"><span class="t-li">2)</span> A template template parameter with an optional name and a default.</div>
<div class="t-li1"><span class="t-li">3)</span> A template template <a href="parameter_pack.html" title="cpp/language/parameter pack">parameter pack</a> with an optional name.</div>
<table class="t-rev-begin">
<tr class="t-rev t-until-cxx17"><td>
<p>Unlike type template parameter declaration, template template parameter declaration can only use the keyword <code><b>class</b></code> and not <code><b>typename</b></code>.
</p>
</td>
<td><span class="t-mark-rev t-until-cxx17">(until C++17)</span></td></tr>
</table>
<p>In the body of the template declaration, the name of this parameter is a template-name (and needs arguments to be instantiated).
</p>
<div dir="ltr" class="mw-geshi" style="text-align: left;"><div class="cpp source-cpp"><pre class="de1"><span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span> T<span class="sy1">></span> <span class="kw1">class</span> my_array <span class="br0">{</span><span class="br0">}</span><span class="sy4">;</span>
 
<span class="co1">// two type template parameters and one template template parameter:</span>
<span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span> K, <span class="kw1">typename</span> V, <span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span><span class="sy1">></span> <span class="kw1">typename</span> C <span class="sy1">=</span> my_array<span class="sy1">></span>
<span class="kw1">class</span> Map
<span class="br0">{</span>
C<span class="sy1"><</span>K<span class="sy1">></span> key<span class="sy4">;</span>
C<span class="sy1"><</span>V<span class="sy1">></span> value<span class="sy4">;</span>
<span class="br0">}</span><span class="sy4">;</span></pre></div></div>
<h3><span class="editsection">[<a href="http://en.cppreference.com/mwiki/index.php?title=cpp/language/template_parameters&action=edit&section=4" title="Edit section: Template arguments">edit</a>]</span> <span class="mw-headline" id="Template_arguments">Template arguments</span></h3>
<p>In order for a template to be instantiated, every template parameter (type, non-type, or template) must be replaced by a corresponding template argument. For <a href="class_template.html" title="cpp/language/class template">class templates</a>, the arguments are either explicitly provided or defaulted. For <a href="function_template.html" title="cpp/language/function template">function templates</a>, the arguments are explicitly provided, defaulted, or <a href="template_argument_deduction.html" title="cpp/language/template argument deduction">deduced from context</a>.
</p><p>If an argument can be interpreted as a both a <a href="type-id.html" title="cpp/language/type-id" class="mw-redirect">type-id</a> and an expression, it is always interpreted as a type-id, even if the corresponding template parameter is non-type:
</p>
<div dir="ltr" class="mw-geshi" style="text-align: left;"><div class="cpp source-cpp"><pre class="de1"><span class="kw1">template</span><span class="sy1"><</span><span class="kw1">class</span> T<span class="sy1">></span> <span class="kw4">void</span> f<span class="br0">(</span><span class="br0">)</span><span class="sy4">;</span> <span class="co1">// #1</span>
<span class="kw1">template</span><span class="sy1"><</span><span class="kw4">int</span> I<span class="sy1">></span> <span class="kw4">void</span> f<span class="br0">(</span><span class="br0">)</span><span class="sy4">;</span> <span class="co1">// #2</span>
<span class="kw4">void</span> g<span class="br0">(</span><span class="br0">)</span> <span class="br0">{</span>
f<span class="sy1"><</span><span class="kw4">int</span><span class="br0">(</span><span class="br0">)</span><span class="sy1">></span><span class="br0">(</span><span class="br0">)</span><span class="sy4">;</span> <span class="co1">// "int()" is both a type and an expression,</span>
<span class="co1">// calls #1 because it is interpreted as a type</span>
<span class="br0">}</span></pre></div></div>
<h4><span class="editsection">[<a href="http://en.cppreference.com/mwiki/index.php?title=cpp/language/template_parameters&action=edit&section=5" title="Edit section: Template non-type arguments">edit</a>]</span> <span class="mw-headline" id="Template_non-type_arguments">Template non-type arguments</span></h4>
<p>The following limitations apply when instantiating templates that have non-type template parameters:
</p>
<table class="t-rev-begin">
<tr class="t-rev t-until-cxx17"><td>
<ul><li> For integral and arithmetic types, the template argument provided during instantiation must be a <a href="constant_expression.html" title="cpp/language/constant expression">converted constant expression</a> of the template parameter's type (so certain implicit conversion applies).
</li><li> For pointers to objects, the template arguments have to designate the address of an object with static <a href="storage_duration.html" title="cpp/language/storage duration">storage duration</a> and a <a href="storage_duration.html#Linkage" title="cpp/language/storage duration">linkage</a> (either internal or external), or a constant expression that evaluates to the appropriate null pointer or <span class="t-lc"><a href="../types/nullptr_t.html" title="cpp/types/nullptr t">std::nullptr_t</a></span> value.
</li><li> For pointers to functions, the valid arguments are pointers to functions with linkage (or constant expressions that evaluate to null pointer values).
</li><li> For lvalue reference parameters, the argument provided at instantiation cannot be a temporary, an unnamed lvalue, or a named lvalue with no linkage (in other words, the argument must have linkage).
</li><li> For pointers to members, the argument has to be a pointer to member expressed as <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="sy3">&</span>Class<span class="sy4">::</span><span class="me2">Member</span></span></span> or a constant expression that evaluates to null pointer or <span class="t-lc"><a href="../types/nullptr_t.html" title="cpp/types/nullptr t">std::nullptr_t</a></span> value.
</li></ul>
<p>In particular, this implies that string literals, addresses of array elements, and addresses of non-static members cannot be used as template arguments to instantiate templates whose corresponding non-type template parameters are pointers to objects.
</p>
</td>
<td><span class="t-mark-rev t-until-cxx17">(until C++17)</span></td></tr>
<tr class="t-rev t-since-cxx17"><td>
<p>The template argument that can be used with a non-type template parameter can be any <a href="constant_expression.html" title="cpp/language/constant expression">converted constant expression</a> of the type of the template parameter.
</p>
<div dir="ltr" class="mw-geshi" style="text-align: left;"><div class="cpp source-cpp"><pre class="de1"><span class="kw1">template</span><span class="sy1"><</span><span class="kw4">const</span> <span class="kw4">int</span><span class="sy2">*</span> pci<span class="sy1">></span> <span class="kw1">struct</span> X <span class="br0">{</span><span class="br0">}</span><span class="sy4">;</span>
<span class="kw4">int</span> ai<span class="br0">[</span><span class="nu0">10</span><span class="br0">]</span><span class="sy4">;</span>
X<span class="sy1"><</span>ai<span class="sy1">></span> xi<span class="sy4">;</span> <span class="co1">// ok: array to pointer conversion and cv-qualification conversion</span>
 
<span class="kw1">struct</span> Y <span class="br0">{</span><span class="br0">}</span><span class="sy4">;</span>
<span class="kw1">template</span><span class="sy1"><</span><span class="kw4">const</span> Y<span class="sy3">&</span> b<span class="sy1">></span> <span class="kw1">struct</span> Z <span class="br0">{</span><span class="br0">}</span><span class="sy4">;</span>
Y y<span class="sy4">;</span>
Z<span class="sy1"><</span>y<span class="sy1">></span> z<span class="sy4">;</span> <span class="co1">// ok: no conversion and cv-qualification conversion</span>
 
<span class="kw1">template</span><span class="sy1"><</span><span class="kw4">int</span> <span class="br0">(</span><span class="sy3">&</span>pa<span class="br0">)</span><span class="br0">[</span><span class="nu0">5</span><span class="br0">]</span><span class="sy1">></span> <span class="kw1">struct</span> W <span class="br0">{</span><span class="br0">}</span><span class="sy4">;</span>
<span class="kw4">int</span> b<span class="br0">[</span><span class="nu0">5</span><span class="br0">]</span><span class="sy4">;</span>
W<span class="sy1"><</span>b<span class="sy1">></span> w<span class="sy4">;</span> <span class="co1">// ok: no conversion</span>
 
<span class="kw4">void</span> f<span class="br0">(</span><span class="kw4">char</span><span class="br0">)</span><span class="sy4">;</span>
<span class="kw4">void</span> f<span class="br0">(</span><span class="kw4">int</span><span class="br0">)</span><span class="sy4">;</span>
<span class="kw1">template</span><span class="sy1"><</span><span class="kw4">void</span> <span class="br0">(</span><span class="sy2">*</span>pf<span class="br0">)</span><span class="br0">(</span><span class="kw4">int</span><span class="br0">)</span><span class="sy1">></span> <span class="kw1">struct</span> A <span class="br0">{</span><span class="br0">}</span><span class="sy4">;</span>
A<span class="sy1"><</span><span class="sy3">&</span>f<span class="sy1">></span> a<span class="sy4">;</span> <span class="co1">// ok: overload resolution selects f(int)</span></pre></div></div>
<p>The only exceptions are that non-type template parameters of <i>reference</i> and <i>pointer</i> type cannot refer to/be the address of
</p>
<ul><li> a subobject (including non-static class member, base subobject, or array element);
</li><li> a temporary object (including one created during <a href="reference_initialization.html" title="cpp/language/reference initialization">reference initialization</a>);
</li><li> a <a href="string_literal.html" title="cpp/language/string literal">string literal</a>;
</li><li> the result of <a href="typeid.html" title="cpp/language/typeid">typeid</a>;
</li><li> or the predefined variable <span class="t-c"><span class="mw-geshi cpp source-cpp">__func__</span></span>.
</li></ul>
<div dir="ltr" class="mw-geshi" style="text-align: left;"><div class="cpp source-cpp"><pre class="de1"><span class="kw1">template</span><span class="sy1"><</span><span class="kw1">class</span> T, <span class="kw4">const</span> <span class="kw4">char</span><span class="sy2">*</span> p<span class="sy1">></span> <span class="kw1">class</span> X <span class="br0">{</span><span class="br0">}</span><span class="sy4">;</span>
X<span class="sy1"><</span><span class="kw4">int</span>, <span class="st0">"Studebaker"</span><span class="sy1">></span> x1<span class="sy4">;</span> <span class="co1">// error: string literal as template-argument</span>
 
<span class="kw1">template</span><span class="sy1"><</span><span class="kw4">int</span><span class="sy2">*</span> p<span class="sy1">></span> <span class="kw1">class</span> X <span class="br0">{</span><span class="br0">}</span><span class="sy4">;</span>
<span class="kw4">int</span> a<span class="br0">[</span><span class="nu0">10</span><span class="br0">]</span><span class="sy4">;</span>
<span class="kw1">struct</span> S
<span class="br0">{</span>
<span class="kw4">int</span> m<span class="sy4">;</span>
<span class="kw4">static</span> <span class="kw4">int</span> s<span class="sy4">;</span>
<span class="br0">}</span> s<span class="sy4">;</span>
X<span class="sy1"><</span><span class="sy3">&</span>a<span class="br0">[</span><span class="nu0">2</span><span class="br0">]</span><span class="sy1">></span> x3<span class="sy4">;</span> <span class="co1">// error: address of array element</span>
X<span class="sy1"><</span><span class="sy3">&</span>s.<span class="me1">m</span><span class="sy1">></span> x4<span class="sy4">;</span> <span class="co1">// error: address of non-static member</span>
X<span class="sy1"><</span><span class="sy3">&</span>s.<span class="me1">s</span><span class="sy1">></span> x5<span class="sy4">;</span> <span class="co1">// ok: address of static member</span>
X<span class="sy1"><</span><span class="sy3">&</span>S<span class="sy4">::</span><span class="me2">s</span><span class="sy1">></span> x6<span class="sy4">;</span> <span class="co1">// ok: address of static member</span>
 
<span class="kw1">template</span><span class="sy1"><</span><span class="kw4">const</span> <span class="kw4">int</span><span class="sy3">&</span> CRI<span class="sy1">></span> <span class="kw1">struct</span> B <span class="br0">{</span><span class="br0">}</span><span class="sy4">;</span>
B<span class="sy1"><</span><span class="nu0">1</span><span class="sy1">></span> b2<span class="sy4">;</span> <span class="co1">// error: temporary would be required for template argument</span>
<span class="kw4">int</span> c <span class="sy1">=</span> <span class="nu0">1</span><span class="sy4">;</span>
B<span class="sy1"><</span>c<span class="sy1">></span> b1<span class="sy4">;</span> <span class="co1">// ok</span></pre></div></div>
</td>
<td><span class="t-mark-rev t-since-cxx17">(since C++17)</span></td></tr>
</table>
<h4><span class="editsection">[<a href="http://en.cppreference.com/mwiki/index.php?title=cpp/language/template_parameters&action=edit&section=6" title="Edit section: Template type arguments">edit</a>]</span> <span class="mw-headline" id="Template_type_arguments">Template type arguments</span></h4>
<p>A template argument for a type template parameter must be a <a href="type-id.html#Type_naming" title="cpp/language/type">type-id</a>, which may name an incomplete type:
</p>
<div dir="ltr" class="mw-geshi" style="text-align: left;"><div class="cpp source-cpp"><pre class="de1"><span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span> T<span class="sy1">></span> <span class="kw1">class</span> X <span class="br0">{</span><span class="br0">}</span><span class="sy4">;</span> <span class="co1">// class template</span>
 
<span class="kw1">struct</span> A<span class="sy4">;</span> <span class="co1">// incomplete type</span>
<span class="kw1">typedef</span> <span class="kw1">struct</span> <span class="br0">{</span><span class="br0">}</span> B<span class="sy4">;</span> <span class="co1">// type alias to an unnamed type</span>
 
<span class="kw4">int</span> main<span class="br0">(</span><span class="br0">)</span>
<span class="br0">{</span>
X<span class="sy1"><</span>A<span class="sy1">></span> x1<span class="sy4">;</span> <span class="co1">// ok: 'A' names a type</span>
X<span class="sy1"><</span>A<span class="sy2">*</span><span class="sy1">></span> x2<span class="sy4">;</span> <span class="co1">// ok: 'A*' names a type</span>
X<span class="sy1"><</span>B<span class="sy1">></span> x3<span class="sy4">;</span> <span class="co1">// ok: 'B' names a type</span>
<span class="br0">}</span></pre></div></div>
<h4><span class="editsection">[<a href="http://en.cppreference.com/mwiki/index.php?title=cpp/language/template_parameters&action=edit&section=7" title="Edit section: Template template arguments">edit</a>]</span> <span class="mw-headline" id="Template_template_arguments">Template template arguments</span></h4>
<p>A template argument for a template template parameter must be an <a href="name.html#In_expressions" title="cpp/language/identifiers">id-expression</a> which names a class template or a template alias.
</p><p>When the argument is a class template, only the primary template is considered when matching the parameter. The partial specializations, if any, are only considered when a specialization based on this template template parameter happens to be instantiated.
</p>
<div dir="ltr" class="mw-geshi" style="text-align: left;"><div class="cpp source-cpp"><pre class="de1"><span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span> T<span class="sy1">></span> <span class="kw1">class</span> A <span class="br0">{</span> <span class="kw4">int</span> x<span class="sy4">;</span> <span class="br0">}</span><span class="sy4">;</span> <span class="co1">// primary template</span>
<span class="kw1">template</span><span class="sy1"><</span><span class="kw1">class</span> T<span class="sy1">></span> <span class="kw1">class</span> A<span class="sy1"><</span>T<span class="sy2">*</span><span class="sy1">></span> <span class="br0">{</span> <span class="kw4">long</span> x<span class="sy4">;</span> <span class="br0">}</span><span class="sy4">;</span> <span class="co1">// partial specialization</span>
 
<span class="co1">// class template with a template template parameter V</span>
<span class="kw1">template</span><span class="sy1"><</span><span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span><span class="sy1">></span> <span class="kw1">class</span> V<span class="sy1">></span> <span class="kw1">class</span> C
<span class="br0">{</span>
V<span class="sy1"><</span><span class="kw4">int</span><span class="sy1">></span> y<span class="sy4">;</span> <span class="co1">// uses the primary template</span>
V<span class="sy1"><</span><span class="kw4">int</span><span class="sy2">*</span><span class="sy1">></span> z<span class="sy4">;</span> <span class="co1">// uses the partial specialization</span>
<span class="br0">}</span><span class="sy4">;</span>
 
C<span class="sy1"><</span>A<span class="sy1">></span> c<span class="sy4">;</span> <span class="co1">// c.y.x has type int, c.z.x has type long</span></pre></div></div>
<p>To match a template template argument <code>A</code> to a template template parameter <code>P</code>, each of the template parameters of <code>A</code> must match corresponding template parameters of <code>P</code>. If <code>P</code>'s parameter list includes a <a href="parameter_pack.html" title="cpp/language/parameter pack">parameter pack</a>, zero or more template parameters (or parameter packs) from <code>A</code>'s template parameter list are matched by it.
</p>
<div dir="ltr" class="mw-geshi" style="text-align: left;"><div class="cpp source-cpp"><pre class="de1"><span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span> T<span class="sy1">></span> <span class="kw1">struct</span> eval<span class="sy4">;</span> <span class="co1">// primary template </span>
 
<span class="kw1">template</span><span class="sy1"><</span><span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span>, <span class="kw1">typename</span>...<span class="sy1">></span> <span class="kw1">class</span> TT, <span class="kw1">typename</span> T1, <span class="kw1">typename</span>... <span class="me1">Rest</span><span class="sy1">></span>
<span class="kw1">struct</span> eval<span class="sy1"><</span>TT<span class="sy1"><</span>T1, Rest...<span class="sy1">>></span> <span class="br0">{</span><span class="br0">}</span><span class="sy4">;</span> <span class="co1">// partial specialization of eval</span>
 
<span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span> T1<span class="sy1">></span> <span class="kw1">struct</span> A<span class="sy4">;</span>
<span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span> T1, <span class="kw1">typename</span> T2<span class="sy1">></span> <span class="kw1">struct</span> B<span class="sy4">;</span>
<span class="kw1">template</span><span class="sy1"><</span><span class="kw4">int</span> N<span class="sy1">></span> <span class="kw1">struct</span> C<span class="sy4">;</span>
<span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span> T1, <span class="kw4">int</span> N<span class="sy1">></span> <span class="kw1">struct</span> D<span class="sy4">;</span>
<span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span> T1, <span class="kw1">typename</span> T2, <span class="kw4">int</span> N <span class="sy1">=</span> <span class="nu0">17</span><span class="sy1">></span> <span class="kw1">struct</span> E<span class="sy4">;</span>
 
eval<span class="sy1"><</span>A<span class="sy1"><</span><span class="kw4">int</span><span class="sy1">>></span> eA<span class="sy4">;</span> <span class="co1">// ok: matches partial specialization of eval</span>
eval<span class="sy1"><</span>B<span class="sy1"><</span><span class="kw4">int</span>, <span class="kw4">float</span><span class="sy1">>></span> eB<span class="sy4">;</span> <span class="co1">// ok: matches partial specialization of eval</span>
eval<span class="sy1"><</span>C<span class="sy1"><</span><span class="nu0">17</span><span class="sy1">>></span> eC<span class="sy4">;</span> <span class="co1">// error: C does not match TT in partial specialization because</span>
<span class="co1">// TT's first parameter is a type template parameter,</span>
<span class="co1">// while 17 does not name a type</span>
eval<span class="sy1"><</span>D<span class="sy1"><</span><span class="kw4">int</span>, <span class="nu0">17</span><span class="sy1">>></span> eD<span class="sy4">;</span> <span class="co1">// error: D does not match TT in partial specialization</span>
<span class="co1">// because TT's second parameter is a type parameter pack,</span>
<span class="co1">// while 17 does not name a type</span>
eval<span class="sy1"><</span>E<span class="sy1"><</span><span class="kw4">int</span>, <span class="kw4">float</span><span class="sy1">>></span> eE<span class="sy4">;</span> <span class="co1">// error: E does not match TT in partial specialization</span>
<span class="co1">// because E's third (default) parameter is a non-type</span></pre></div></div>
<h4><span class="editsection">[<a href="http://en.cppreference.com/mwiki/index.php?title=cpp/language/template_parameters&action=edit&section=8" title="Edit section: Default template arguments">edit</a>]</span> <span class="mw-headline" id="Default_template_arguments">Default template arguments</span></h4>
<p>Default template arguments are specified in the parameter lists after the <span class="t-c"><span class="mw-geshi cpp source-cpp"><span class="sy1">=</span></span></span> sign. Defaults can be specified for any kind of template parameter (type, non-type, or template), but not to parameter packs.
</p><p>If the default is specified for a template parameter of a primary class template, each subsequent template parameter must have a default argument, except the very last one may be a template parameter pack. In a function template, a parameter pack may be followed by more type parameters only if they have defaults or can be deduced from the function arguments.
</p><p>Default parameters are not allowed
</p>
<ul><li> in the out-of-class definition of a <a href="member_template.html" title="cpp/language/member template">member template</a> (they have to be provided in the declaration inside the class body)
</li><li> in <a href="friend.html#Template_friends" title="cpp/language/friend">friend class template</a> declarations
</li></ul>
<table class="t-rev-begin">
<tr class="t-rev t-until-cxx11"><td>
<ul><li> in any <a href="function_template.html" title="cpp/language/function template">function template</a> declaration or definition
</li></ul>
</td>
<td><span class="t-mark-rev t-until-cxx11">(until C++11)</span></td></tr>
</table>
<table class="t-rev-begin">
<tr class="t-rev t-since-cxx11"><td>
<p>On a friend function template declaration, default template arguments are allowed only if the declaration is a definition, and no other declarations of this function appear in this translation unit.
</p>
</td>
<td><span class="t-mark-rev t-since-cxx11">(since C++11)</span></td></tr>
</table>
<p>Default template arguments that appear in the declarations and the definition are merged similarly to default function arguments:
</p>
<div dir="ltr" class="mw-geshi" style="text-align: left;"><div class="cpp source-cpp"><pre class="de1"><span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span> T1, <span class="kw1">typename</span> T2 <span class="sy1">=</span> <span class="kw4">int</span><span class="sy1">></span> <span class="kw1">class</span> A<span class="sy4">;</span>
<span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span> T1 <span class="sy1">=</span> <span class="kw4">int</span>, <span class="kw1">typename</span> T2<span class="sy1">></span> <span class="kw1">class</span> A<span class="sy4">;</span>
<span class="co1">// the above is the same as the following:</span>
<span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span> T1 <span class="sy1">=</span> <span class="kw4">int</span>, <span class="kw1">typename</span> T2 <span class="sy1">=</span> <span class="kw4">int</span><span class="sy1">></span> <span class="kw1">class</span> A<span class="sy4">;</span></pre></div></div>
<p>But the same parameter cannot be given default arguments twice in the same scope
</p>
<div dir="ltr" class="mw-geshi" style="text-align: left;"><div class="cpp source-cpp"><pre class="de1"><span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span> T <span class="sy1">=</span> <span class="kw4">int</span><span class="sy1">></span> <span class="kw1">class</span> X<span class="sy4">;</span>
<span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span> T <span class="sy1">=</span> <span class="kw4">int</span><span class="sy1">></span> <span class="kw1">class</span> X <span class="br0">{</span><span class="br0">}</span><span class="sy4">;</span> <span class="co1">// error</span></pre></div></div>
<p>The template parameter lists of template template parameters can have their own default arguments, which are only in effect where the template template parameter itself is in scope:
</p>
<div dir="ltr" class="mw-geshi" style="text-align: left;"><div class="cpp source-cpp"><pre class="de1"><span class="co1">// class template, with a type template parameter with a default</span>
<span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span> T <span class="sy1">=</span> <span class="kw4">float</span><span class="sy1">></span> <span class="kw1">struct</span> B <span class="br0">{</span><span class="br0">}</span><span class="sy4">;</span>
 
<span class="co1">// template template parameter T has a parameter list, which </span>
<span class="co1">// consists of one type template parameter with a default</span>
<span class="kw1">template</span><span class="sy1"><</span><span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span> <span class="sy1">=</span> <span class="kw4">float</span><span class="sy1">></span> <span class="kw1">typename</span> T<span class="sy1">></span> <span class="kw1">struct</span> A
<span class="br0">{</span>
<span class="kw4">void</span> f<span class="br0">(</span><span class="br0">)</span><span class="sy4">;</span>
<span class="kw4">void</span> g<span class="br0">(</span><span class="br0">)</span><span class="sy4">;</span>
<span class="br0">}</span><span class="sy4">;</span>
 
<span class="co1">// out-of-body member function template definitions</span>
<span class="kw1">template</span><span class="sy1"><</span><span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span> TT<span class="sy1">></span> <span class="kw1">class</span> T<span class="sy1">></span>
<span class="kw4">void</span> A<span class="sy1"><</span>T<span class="sy1">></span><span class="sy4">::</span><span class="me2">f</span><span class="br0">(</span><span class="br0">)</span>
<span class="br0">{</span>
T<span class="sy1"><></span> t<span class="sy4">;</span> <span class="co1">// error: TT has no default in scope</span>
<span class="br0">}</span>
<span class="kw1">template</span><span class="sy1"><</span><span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span> TT <span class="sy1">=</span> <span class="kw4">char</span><span class="sy1">></span> <span class="kw1">class</span> T<span class="sy1">></span>
<span class="kw4">void</span> A<span class="sy1"><</span>T<span class="sy1">></span><span class="sy4">::</span><span class="me2">g</span><span class="br0">(</span><span class="br0">)</span>
<span class="br0">{</span>
T<span class="sy1"><></span> t<span class="sy4">;</span> <span class="co1">// ok: t is T<char></span>
<span class="br0">}</span></pre></div></div>
<p><a href="access.html" title="cpp/language/access">Member access</a> for the names used in a default template parameter is checked at the declaration, not at the point of use:
</p>
<div dir="ltr" class="mw-geshi" style="text-align: left;"><div class="cpp source-cpp"><pre class="de1"><span class="kw1">class</span> B <span class="br0">{</span><span class="br0">}</span><span class="sy4">;</span>
 
<span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span> T<span class="sy1">></span> <span class="kw1">class</span> C
<span class="br0">{</span>
<span class="kw1">protected</span><span class="sy4">:</span>
<span class="kw1">typedef</span> T TT<span class="sy4">;</span>
<span class="br0">}</span><span class="sy4">;</span>
 
<span class="kw1">template</span><span class="sy1"><</span><span class="kw1">typename</span> U, <span class="kw1">typename</span> V <span class="sy1">=</span> <span class="kw1">typename</span> U<span class="sy4">::</span><span class="me2">TT</span><span class="sy1">></span> <span class="kw1">class</span> D<span class="sy4">:</span> <span class="kw1">public</span> U <span class="br0">{</span><span class="br0">}</span><span class="sy4">;</span>
 
D<span class="sy1"><</span>C<span class="sy1"><</span>B<span class="sy1">>></span><span class="sy2">*</span> d<span class="sy4">;</span> <span class="co1">// error: C::TT is protected</span></pre></div></div>
<p><br />
</p>
<h3><span class="editsection">[<a href="http://en.cppreference.com/mwiki/index.php?title=cpp/language/template_parameters&action=edit&section=9" title="Edit section: Examples">edit</a>]</span> <span class="mw-headline" id="Examples">Examples</span></h3>
<h4><span class="editsection">[<a href="http://en.cppreference.com/mwiki/index.php?title=cpp/language/template_parameters&action=edit&section=10" title="Edit section: Non-type template parameters">edit</a>]</span> <span class="mw-headline" id="Non-type_template_parameters">Non-type template parameters</span></h4>
<div class="t-example"><div class="t-example-live-link"><div class="coliru-btn coliru-btn-run-init">Run this code</div></div>
<div dir="ltr" class="mw-geshi" style="text-align: left;"><div class="cpp source-cpp"><pre class="de1"><span class="co2">#include <iostream></span>
 
<span class="co1">// simple non-type template parameter</span>
<span class="kw1">template</span><span class="sy1"><</span><span class="kw4">int</span> N<span class="sy1">></span>
<span class="kw1">struct</span> S <span class="br0">{</span> <span class="kw4">int</span> a<span class="br0">[</span>N<span class="br0">]</span><span class="sy4">;</span> <span class="br0">}</span><span class="sy4">;</span>
 
<span class="kw1">template</span><span class="sy1"><</span><span class="kw4">const</span> <span class="kw4">char</span><span class="sy2">*</span><span class="sy1">></span>
<span class="kw1">struct</span> S2 <span class="br0">{</span><span class="br0">}</span><span class="sy4">;</span>
 
<span class="co1">// complicated non-type example</span>
<span class="kw1">template</span>
<span class="sy1"><</span>
<span class="kw4">char</span> c, <span class="co1">// integral type</span>
<span class="kw4">int</span> <span class="br0">(</span><span class="sy3">&</span>ra<span class="br0">)</span><span class="br0">[</span><span class="nu0">5</span><span class="br0">]</span>, <span class="co1">// lvalue reference to object (of array type)</span>
<span class="kw4">int</span> <span class="br0">(</span><span class="sy2">*</span>pf<span class="br0">)</span><span class="br0">(</span><span class="kw4">int</span><span class="br0">)</span>, <span class="co1">// pointer to function</span>
<span class="kw4">int</span> <span class="br0">(</span>S<span class="sy1"><</span><span class="nu0">10</span><span class="sy1">></span><span class="sy4">::</span><span class="sy2">*</span>a<span class="br0">)</span><span class="br0">[</span><span class="nu0">10</span><span class="br0">]</span> <span class="co1">// pointer to member object (of type int[10])</span>
<span class="sy1">></span> <span class="kw1">struct</span> Complicated
<span class="br0">{</span>
<span class="co1">// calls the function selected at compile time</span>
<span class="co1">// and stores the result in the array selected at compile time</span>
<span class="kw4">void</span> foo<span class="br0">(</span><span class="kw4">char</span> base<span class="br0">)</span>
<span class="br0">{</span>
ra<span class="br0">[</span><span class="nu0">4</span><span class="br0">]</span> <span class="sy1">=</span> pf<span class="br0">(</span>c <span class="sy2">-</span> base<span class="br0">)</span><span class="sy4">;</span>
<span class="br0">}</span>
<span class="br0">}</span><span class="sy4">;</span>
 
S2<span class="sy1"><</span><span class="st0">"fail"</span><span class="sy1">></span> s2<span class="sy4">;</span> <span class="co1">// error: string literal cannot be used</span>
<span class="kw4">char</span> okay<span class="br0">[</span><span class="br0">]</span> <span class="sy1">=</span> <span class="st0">"okay"</span><span class="sy4">;</span> <span class="co1">// static object with linkage</span>
S2<span class="sy1"><</span> <span class="sy3">&</span>okay<span class="br0">[</span><span class="nu0">0</span><span class="br0">]</span> <span class="sy1">></span> s2<span class="sy4">;</span> <span class="co1">// error: array element has no linkage</span>
S2<span class="sy1"><</span>okay<span class="sy1">></span> s2<span class="sy4">;</span> <span class="co1">// works</span>
 
<span class="kw4">int</span> a<span class="br0">[</span><span class="nu0">5</span><span class="br0">]</span><span class="sy4">;</span>
<span class="kw4">int</span> f<span class="br0">(</span><span class="kw4">int</span> n<span class="br0">)</span> <span class="br0">{</span> <span class="kw1">return</span> n<span class="sy4">;</span> <span class="br0">}</span>
 
<span class="kw4">int</span> main<span class="br0">(</span><span class="br0">)</span>
<span class="br0">{</span>
S<span class="sy1"><</span><span class="nu0">10</span><span class="sy1">></span> s<span class="sy4">;</span> <span class="co1">// s.a is an array of 10 int</span>
s.<span class="me1">a</span><span class="br0">[</span><span class="nu0">9</span><span class="br0">]</span> <span class="sy1">=</span> <span class="nu0">4</span><span class="sy4">;</span>
 
Complicated<span class="sy1"><</span><span class="st0">'2'</span>, a, f, <span class="sy3">&</span>S<span class="sy1"><</span><span class="nu0">10</span><span class="sy1">></span><span class="sy4">::</span><span class="me2">a</span><span class="sy1">></span> c<span class="sy4">;</span>
c.<span class="me1">foo</span><span class="br0">(</span><span class="st0">'0'</span><span class="br0">)</span><span class="sy4">;</span>
 
<a href="../io/cout.html"><span class="kw1481">std::<span class="me2">cout</span></span></a> <span class="sy1"><<</span> s.<span class="me1">a</span><span class="br0">[</span><span class="nu0">9</span><span class="br0">]</span> <span class="sy1"><<</span> a<span class="br0">[</span><span class="nu0">4</span><span class="br0">]</span> <span class="sy1"><<</span> <span class="st0">'<span class="es1">\n</span>'</span><span class="sy4">;</span>
<span class="br0">}</span></pre></div></div>
<p>Output:
</p>
<div dir="ltr" class="mw-geshi" style="text-align: left;"><div class="text source-text"><pre class="de1">42</pre></div></div>
</div>
<table class="metadata plainlinks ambox mbox-small-left ambox-notice" style=""><tr><td class="mbox-empty-cell"></td><td class="mbox-text" style="">This section is incomplete<br />Reason: more examples </td></tr></table>
<!--
NewPP limit report
Preprocessor visited node count: 2671/1000000
Preprocessor generated node count: 9513/1000000
Post‐expand include size: 48545/2097152 bytes
Template argument size: 20006/2097152 bytes
Highest expansion depth: 17/40
Expensive parser function count: 0/100
-->
<!-- Saved in parser cache with key mwiki1-mwiki_en_:pcache:idhash:13162-0!*!0!!en!*!* and timestamp 20151113145823 -->
</div> <!-- /bodycontent -->
<!-- printfooter -->
<div class="printfooter">
Retrieved from "<a href="http://en.cppreference.com/mwiki/index.php?title=cpp/language/template_parameters&oldid=81843">http://en.cppreference.com/mwiki/index.php?title=cpp/language/template_parameters&oldid=81843</a>" </div>
<!-- /printfooter -->
<!-- catlinks -->
<div id='catlinks' class='catlinks'><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="http://en.cppreference.com/w/Special:Categories" title="Special:Categories">Category</a>: <ul><li><a href="http://en.cppreference.com/w/Category:Todo_with_reason" title="Category:Todo with reason">Todo with reason</a></li></ul></div></div> <!-- /catlinks -->
<div class="visualClear"></div>
<!-- debughtml -->
<!-- /debughtml -->
</div>
<!-- /bodyContent -->
</div>
</div>
<!-- /content -->
<!-- footer -->
<div id="cpp-footer-base" class="noprint">
<div id="footer">
<div id="cpp-navigation">
<h5>Navigation</h5>
<ul>
<li id="n-Support-us"><a href="http://www.cppreference.com/support" rel="nofollow">Support us</a></li><li id="n-recentchanges"><a href="http://en.cppreference.com/w/Special:RecentChanges" title="A list of recent changes in the wiki [r]" accesskey="r">Recent changes</a></li><li id="n-FAQ"><a href="http://en.cppreference.com/w/Cppreference:FAQ">FAQ</a></li><li id="n-Offline-version"><a href="http://en.cppreference.com/w/Cppreference:Archives">Offline version</a></li> </ul>
</div>
<div id="cpp-toolbox">
<h5><span>Toolbox</span><a href="template_parameters.html#"></a></h5>
<ul>
<li id="t-whatlinkshere"><a href="http://en.cppreference.com/w/Special:WhatLinksHere/cpp/language/template_parameters" title="A list of all wiki pages that link here [j]" accesskey="j">What links here</a></li><li id="t-recentchangeslinked"><a href="http://en.cppreference.com/w/Special:RecentChangesLinked/cpp/language/template_parameters" title="Recent changes in pages linked from this page [k]" accesskey="k">Related changes</a></li><li id="t-upload"><a href="http://upload.cppreference.com/w/Special:Upload" title="Upload files [u]" accesskey="u">Upload file</a></li><li id="t-specialpages"><a href="http://en.cppreference.com/w/Special:SpecialPages" title="A list of all special pages [q]" accesskey="q">Special pages</a></li><li id="t-print"><a href="http://en.cppreference.com/mwiki/index.php?title=cpp/language/template_parameters&printable=yes" rel="alternate" title="Printable version of this page [p]" accesskey="p">Printable version</a></li><li id="t-permalink"><a href="http://en.cppreference.com/mwiki/index.php?title=cpp/language/template_parameters&oldid=81843" title="Permanent link to this revision of the page">Permanent link</a></li><li id="t-info"><a href="http://en.cppreference.com/mwiki/index.php?title=cpp/language/template_parameters&action=info">Page information</a></li> </ul>
</div>
<ul id="footer-info">
<li id="footer-info-lastmod"> This page was last modified on 13 November 2015, at 06:58.</li>
<li id="footer-info-viewcount">This page has been accessed 145,157 times.</li>
</ul>
<ul id="footer-places">
<li id="footer-places-privacy"><a href="http://en.cppreference.com/w/Cppreference:Privacy_policy" title="Cppreference:Privacy policy">Privacy policy</a></li>
<li id="footer-places-about"><a href="http://en.cppreference.com/w/Cppreference:About" title="Cppreference:About">About cppreference.com</a></li>
<li id="footer-places-disclaimer"><a href="http://en.cppreference.com/w/Cppreference:General_disclaimer" title="Cppreference:General disclaimer">Disclaimers</a></li>
</ul>
<ul id="footer-icons" class="noprint">
<li id="footer-poweredbyico">
<a href="http://www.mediawiki.org/"><img src="../../../mwiki/skins/common/images/poweredby_mediawiki_88x31.png" alt="Powered by MediaWiki" width="88" height="31" /></a> <a href="http://qbnz.com/highlighter/"><img src="../../../../upload.cppreference.com/mwiki/images/2/2b/powered_by_geshi_88x31.png" alt="Powered by GeSHi" height="31" width="88" /></a> <a href="http://www.tigertech.net/referral/cppreference.com"><img src="../../../../upload.cppreference.com/mwiki/images/9/94/powered_by_tigertech_88x31.png" alt="Hosted by Tiger Technologies" height="31" width="88" /></a> </li>
</ul>
<div style="clear:both">
</div>
</div>
</div>
<!-- /footer -->
<script>if(window.mw){
mw.loader.state({"site":"loading","user":"missing","user.groups":"ready"});
}</script>
<script src="../../../mwiki/load.php%3Fdebug=false&lang=en&modules=skins.cppreference2&only=scripts&skin=cppreference2&*"></script>
<script>if(window.mw){
mw.loader.load(["mediawiki.action.view.postEdit","mediawiki.user","mediawiki.page.ready","mediawiki.searchSuggest","mediawiki.hidpi","ext.gadget.ColiruCompiler"], null, true);
}</script>
<script src="../../../mwiki/load.php%3Fdebug=false&lang=en&modules=site&only=scripts&skin=cppreference2&*"></script>
<script type="text/javascript">
var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www.");
document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E"));
</script>
<script type="text/javascript">
var _gaq = _gaq || [];
_gaq.push(['_setAccount', 'UA-2828341-1']);
_gaq.push(['_setDomainName', 'cppreference.com']);
_gaq.push(['_trackPageview']);
</script><!-- Served in 0.081 secs. -->
</body>
<!-- Cached 20151113145853 -->
</html>
|
