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
|
<!DOCTYPE html>
<html lang="en" dir="ltr" class="client-nojs">
<head>
<title>Floating-point environment - 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=c/numeric/fenv&action=edit" />
<link rel="edit" title="Edit" href="http://en.cppreference.com/mwiki/index.php?title=c/numeric/fenv&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":"c/numeric/fenv","wgTitle":"c/numeric/fenv","wgCurRevisionId":78965,"wgArticleId":6421,"wgIsArticle":true,"wgAction":"view","wgUserName":null,"wgUserGroups":["*"],"wgCategories":[],"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":"c/numeric/fenv","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-c {line-height: normal;}
.source-c li, .source-c pre {
line-height: normal; border: 0px none white;
}
/**
* GeSHi Dynamically Generated Stylesheet
* --------------------------------------
* Dynamically generated stylesheet for c
* CSS class: source-c, CSS id:
* GeSHi (C) 2004 - 2007 Nigel McNie, 2007 - 2008 Benny Baumann
* (http://qbnz.com/highlighter/ and http://geshi.org/)
* --------------------------------------
*/
.c.source-c .de1, .c.source-c .de2 {font: normal normal 1em/1.2em monospace; margin:0; padding:0; background:none; vertical-align:top;}
.c.source-c {font-family:monospace;}
.c.source-c .imp {font-weight: bold; color: red;}
.c.source-c li, .c.source-c .li1 {font-weight: normal; vertical-align:top;}
.c.source-c .ln {width:1px;text-align:right;margin:0;padding:0 2px;vertical-align:top;}
.c.source-c .li2 {font-weight: bold; vertical-align:top;}
.c.source-c .kw1 {color: #0000dd;}
.c.source-c .kw2 {color: #0000ff;}
.c.source-c .kw3 {color: #0000dd;}
.c.source-c .kw4 {color: #0000ff;}
.c.source-c .co1 {color: #909090;}
.c.source-c .co2 {color: #339900;}
.c.source-c .coMULTI {color: #ff0000; font-style: italic;}
.c.source-c .es0 {color: #008000; font-weight: bold;}
.c.source-c .es1 {color: #008000; font-weight: bold;}
.c.source-c .es2 {color: #008000; font-weight: bold;}
.c.source-c .es3 {color: #008000; font-weight: bold;}
.c.source-c .es4 {color: #008000; font-weight: bold;}
.c.source-c .es5 {color: #008000; font-weight: bold;}
.c.source-c .br0 {color: #008000;}
.c.source-c .sy0 {color: #008000;}
.c.source-c .sy1 {color: #000080;}
.c.source-c .sy2 {color: #000040;}
.c.source-c .sy3 {color: #000040;}
.c.source-c .sy4 {color: #008080;}
.c.source-c .st0 {color: #008000;}
.c.source-c .nu0 {color: #000080;}
.c.source-c .nu6 {color:#000080;}
.c.source-c .nu8 {color:#000080;}
.c.source-c .nu12 {color:#000080;}
.c.source-c .nu16 {color:#000080;}
.c.source-c .nu17 {color:#000080;}
.c.source-c .nu18 {color:#000080;}
.c.source-c .nu19 {color:#000080;}
.c.source-c .ln-xtra, .c.source-c li.ln-xtra, .c.source-c div.ln-xtra {background-color: #ffc;}
.c.source-c 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-c_numeric_fenv 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=c%2Fnumeric%2Ffenv&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=c%2Fnumeric%2Ffenv" 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="fenv.html" title="View the content page [c]" accesskey="c">Page</a></span></li>
<li id="ca-talk"><span><a href="http://en.cppreference.com/w/Talk:c/numeric/fenv" 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="fenv.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="fenv.html" >View</a></span></li>
<li id="ca-edit"><span><a href="http://en.cppreference.com/mwiki/index.php?title=c/numeric/fenv&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=c/numeric/fenv&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="fenv.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">Floating-point environment</h1>
<!-- /firstHeading -->
<!-- bodyContent -->
<div id="bodyContent">
<!-- tagline -->
<div id="siteSub">From cppreference.com</div>
<!-- /tagline -->
<!-- subtitle -->
<div id="contentSub"><span class="subpages">< <a href="../../c.html" title="c">c</a>‎ | <a href="../numeric.html" title="c/numeric">numeric</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="../../c.html" title="c"> 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="c/language"> Language</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../header.html" title="c/header"> headers</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../types.html" title="c/types"> Type support</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../memory.html" title="c/memory"> Dynamic memory management</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../error.html" title="c/error"> Error handling</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../program.html" title="c/program"> Program utilities</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../variadic.html" title="c/variadic"> Variadic function support</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../chrono.html" title="c/chrono"> Date and time utilities</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../string.html" title="c/string"> Strings library</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../algorithm.html" title="c/algorithm"> Algorithms</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../numeric.html" title="c/numeric"> Numerics</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../io.html" title="c/io"> Input/output support</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../locale.html" title="c/locale"> Localization support</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../thread.html" title="c/thread"> Thread support</a> <span class="t-mark-rev t-since-c11">(C11)</span> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="../atomic.html" title="c/atomic"> Atomic operations</a> <span class="t-mark-rev t-since-c11">(C11)</span> </td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="../experimental.html" title="c/experimental"><span class="t-lines"><span>Technical Specifications</span></span></a></div></div></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:c/navbar_content&action=edit">[edit]</a></span></div></div></div></div><div class="t-navbar-sep"> </div><div class="t-navbar-head"><a href="../numeric.html" title="c/numeric"> Numerics</a><div class="t-navbar-menu"><div><div><table class="t-nv-begin" cellpadding="0" style="">
<tr class="t-nv"><td colspan="5"> <a href="math.html" title="c/numeric/math">Common mathematical functions</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <strong class="selflink">Floating-point environment</strong> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="complex.html" title="c/numeric/complex">Complex number arithmetics</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="random.html" title="c/numeric/random">Random number generation</a> </td></tr>
<tr class="t-nv"><td colspan="5"> <a href="tgmath.html" title="c/numeric/tgmath">Type-generic math</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:c/numeric/navbar_content&action=edit">[edit]</a></span></div></div></div></div><div class="t-navbar-sep"> </div><div class="t-navbar-head"><strong class="selflink"> Floating point environment</strong><div class="t-navbar-menu"><div><div><table class="t-nv-begin" cellpadding="0" style="">
<tr class="t-nv-h1"><td colspan="5"> Functions</td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="fenv/feclearexcept.html" title="c/numeric/fenv/feclearexcept"><span class="t-lines"><span>feclearexcept</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div></td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="fenv/fetestexcept.html" title="c/numeric/fenv/fetestexcept"><span class="t-lines"><span>fetestexcept</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div></td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="fenv/feraiseexcept.html" title="c/numeric/fenv/feraiseexcept"><span class="t-lines"><span>feraiseexcept</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div></td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="fenv/feexceptflag.html" title="c/numeric/fenv/feexceptflag"><span class="t-lines"><span>fegetexceptflag</span><span>fesetexceptflag</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div></td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="fenv/feround.html" title="c/numeric/fenv/feround"><span class="t-lines"><span>fegetround</span><span>fesetround</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div></td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="fenv/feenv.html" title="c/numeric/fenv/feenv"><span class="t-lines"><span>fegetenv</span><span>fesetenv</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div></td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="fenv/feholdexcept.html" title="c/numeric/fenv/feholdexcept"><span class="t-lines"><span>feholdexcept</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div></td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="fenv/feupdateenv.html" title="c/numeric/fenv/feupdateenv"><span class="t-lines"><span>feupdateenv</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div></td></tr>
<tr class="t-nv-h1"><td colspan="5"> Macro constants</td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="fenv/FE_exceptions.html" title="c/numeric/fenv/FE exceptions"><span class="t-lines"><span>FE_ALL_EXCEPT</span><span>FE_DIVBYZERO</span><span>FE_INEXACT</span><span>FE_INVALID</span><span>FE_OVERFLOW</span><span>FE_UNDERFLOW</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div></td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="fenv/FE_round.html" title="c/numeric/fenv/FE round"><span class="t-lines"><span>FE_DOWNWARD</span><span>FE_TONEAREST</span><span>FE_TOWARDZERO</span><span>FE_UPWARD</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div></td></tr>
<tr class="t-nv"><td colspan="5"><div class="t-nv-ln-table"><div><a href="fenv/FE_DFL_ENV.html" title="c/numeric/fenv/FE DFL ENV"><span class="t-lines"><span>FE_DFL_ENV</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div></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:c/numeric/fenv/navbar_content&action=edit">[edit]</a></span></div></div></div></div><div class="t-navbar-sep"> </div></div>
<p>The floating-point environment is the set of floating-point status flags and control modes supported by the implementation. It is thread-local, each thread inherits the initial state of its floating-point environment from the parent thread. Floating-point operations modify the floating-point status flags to indicate abnormal results or auxiliary information. The state of floating-point control modes affects the outcomes of some floating-point operations.
</p><p>The floating-point environment access and modification is only meaningful when <a href="../../cpp/preprocessor/impl.html" title="cpp/preprocessor/impl"><tt>
#pragma STDC FENV_ACCESS</tt></a> is set to <code>ON</code>. Otherwise the implementation is free to assume that floating-point control modes are always the default ones and that floating-point status flags are never tested or modified. In practice, few current compilers, such as HP aCC, Oracle Studio, and IBM XL, support the <code>#pragma</code> explicitly, but most compilers allow meaningful access to the floating-point environment anyway.
</p>
<table id="toc" class="toc"><tr><td><div id="toctitle"><h2>Contents</h2></div>
<ul>
<li class="toclevel-1 tocsection-1"><a href="fenv.html#Types"><span class="tocnumber">1</span> <span class="toctext">Types</span></a></li>
<li class="toclevel-1 tocsection-2"><a href="fenv.html#Functions"><span class="tocnumber">2</span> <span class="toctext">Functions</span></a></li>
<li class="toclevel-1 tocsection-3"><a href="fenv.html#Macros"><span class="tocnumber">3</span> <span class="toctext">Macros</span></a></li>
<li class="toclevel-1 tocsection-4"><a href="fenv.html#References"><span class="tocnumber">4</span> <span class="toctext">References</span></a></li>
<li class="toclevel-1 tocsection-5"><a href="fenv.html#See_also"><span class="tocnumber">5</span> <span class="toctext">See also</span></a></li>
</ul>
</td></tr></table>
<h3><span class="editsection">[<a href="http://en.cppreference.com/mwiki/index.php?title=c/numeric/fenv&action=edit&section=1" title="Edit section: Types">edit</a>]</span> <span class="mw-headline" id="Types">Types</span></h3>
<table class="t-dsc-begin">
<tr class="t-dsc-header">
<td colspan="2"> <div>Defined in header <code><fenv.h></code> </div>
</td></tr>
<tr class="t-dsc">
<td> <span class="t-c"><span class="mw-geshi c source-c">fenv_t</span></span>
</td>
<td> The type representing the entire floating-point environment
</td></tr>
<tr class="t-dsc">
<td> <span class="t-c"><span class="mw-geshi c source-c">fexcept_t</span></span>
</td>
<td> The type representing all floating-point status flags collectively
</td></tr>
</table>
<h3><span class="editsection">[<a href="http://en.cppreference.com/mwiki/index.php?title=c/numeric/fenv&action=edit&section=2" title="Edit section: Functions">edit</a>]</span> <span class="mw-headline" id="Functions">Functions</span></h3>
<table class="t-dsc-begin">
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="fenv/feclearexcept.html" title="c/numeric/fenv/feclearexcept"> <span class="t-lines"><span>feclearexcept</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div>
</td>
<td> clears the specified floating-point status flags <br /> <span class="t-mark">(function)</span> <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:c/numeric/fenv/dsc_feclearexcept&action=edit">[edit]</a></span>
</td></tr>
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="fenv/fetestexcept.html" title="c/numeric/fenv/fetestexcept"> <span class="t-lines"><span>fetestexcept</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div>
</td>
<td> determines which of the specified floating-point status flags are set <br /> <span class="t-mark">(function)</span> <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:c/numeric/fenv/dsc_fetestexcept&action=edit">[edit]</a></span>
</td></tr>
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="fenv/feraiseexcept.html" title="c/numeric/fenv/feraiseexcept"> <span class="t-lines"><span>feraiseexcept</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div>
</td>
<td> raises the specified floating-point exceptions <br /> <span class="t-mark">(function)</span> <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:c/numeric/fenv/dsc_feraiseexcept&action=edit">[edit]</a></span>
</td></tr>
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="fenv/feexceptflag.html" title="c/numeric/fenv/feexceptflag"> <span class="t-lines"><span>fegetexceptflag</span><span>fesetexceptflag</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div>
</td>
<td> copies the state of the specified floating-point status flags from or to the floating-point environment <br /> <span class="t-mark">(function)</span> <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:c/numeric/fenv/dsc_feexceptflag&action=edit">[edit]</a></span>
</td></tr>
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="fenv/feround.html" title="c/numeric/fenv/feround"> <span class="t-lines"><span>fegetround</span><span>fesetround</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div>
</td>
<td> gets or sets rounding direction <br /> <span class="t-mark">(function)</span> <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:c/numeric/fenv/dsc_feround&action=edit">[edit]</a></span>
</td></tr>
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="fenv/feenv.html" title="c/numeric/fenv/feenv"> <span class="t-lines"><span>fegetenv</span><span>fesetenv</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div>
</td>
<td> saves or restores the current floating point environment <br /> <span class="t-mark">(function)</span> <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:c/numeric/fenv/dsc_feenv&action=edit">[edit]</a></span>
</td></tr>
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="fenv/feholdexcept.html" title="c/numeric/fenv/feholdexcept"> <span class="t-lines"><span>feholdexcept</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div>
</td>
<td> saves the environment, clears all status flags and ignores all future errors <br /> <span class="t-mark">(function)</span> <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:c/numeric/fenv/dsc_feholdexcept&action=edit">[edit]</a></span>
</td></tr>
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="fenv/feupdateenv.html" title="c/numeric/fenv/feupdateenv"> <span class="t-lines"><span>feupdateenv</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div>
</td>
<td> restores the floating-point environment and raises the previously raise exceptions <br /> <span class="t-mark">(function)</span> <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:c/numeric/fenv/dsc_feupdateenv&action=edit">[edit]</a></span>
</td></tr>
</table>
<h3><span class="editsection">[<a href="http://en.cppreference.com/mwiki/index.php?title=c/numeric/fenv&action=edit&section=3" title="Edit section: Macros">edit</a>]</span> <span class="mw-headline" id="Macros">Macros</span></h3>
<table class="t-dsc-begin">
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="fenv/FE_exceptions.html" title="c/numeric/fenv/FE exceptions"> <span class="t-lines"><span>FE_ALL_EXCEPT</span><span>FE_DIVBYZERO</span><span>FE_INEXACT</span><span>FE_INVALID</span><span>FE_OVERFLOW</span><span>FE_UNDERFLOW</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div>
</td>
<td> floating-point exceptions <br /> <span class="t-mark">(macro constant)</span> <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:c/numeric/fenv/dsc_FE_exceptions&action=edit">[edit]</a></span>
</td></tr>
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="fenv/FE_round.html" title="c/numeric/fenv/FE round"> <span class="t-lines"><span>FE_DOWNWARD</span><span>FE_TONEAREST</span><span>FE_TOWARDZERO</span><span>FE_UPWARD</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div>
</td>
<td> floating-point rounding direction <br /> <span class="t-mark">(macro constant)</span> <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:c/numeric/fenv/dsc_FE_round&action=edit">[edit]</a></span>
</td></tr>
<tr class="t-dsc">
<td> <div class="t-dsc-member-div"><div><a href="fenv/FE_DFL_ENV.html" title="c/numeric/fenv/FE DFL ENV"> <span class="t-lines"><span>FE_DFL_ENV</span></span></a></div><div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div></div>
</td>
<td> default floating-point environment <br /> <span class="t-mark">(macro constant)</span> <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:c/numeric/fenv/dsc_FE_DFL_ENV&action=edit">[edit]</a></span>
</td></tr>
</table>
<h3><span class="editsection">[<a href="http://en.cppreference.com/mwiki/index.php?title=c/numeric/fenv&action=edit&section=4" title="Edit section: References">edit</a>]</span> <span class="mw-headline" id="References">References</span></h3>
<div class="t-ref-std-11">
<ul><li> C11 standard (ISO/IEC 9899:2011):
</li></ul>
<dl><dd><ul><li> 7.6 Floating-point environment <fenv.h> (p: 206-215)
</li></ul>
</dd></dl>
<dl><dd><ul><li> 7.31.4 Floating-point environment <fenv.h> (p: 455)
</li></ul>
</dd></dl>
<div class="t-ref-std-c99">
<ul><li> C99 standard (ISO/IEC 9899:1999):
</li></ul>
<dl><dd><ul><li> 7.6 Floating-point environment <fenv.h> (p: 187-196)
</li></ul>
</dd></dl>
</div>
<h3><span class="editsection">[<a href="http://en.cppreference.com/mwiki/index.php?title=c/numeric/fenv&action=edit&section=5" title="Edit section: See also">edit</a>]</span> <span class="mw-headline" id="See_also">See also</span></h3>
<table class="t-dsc-begin">
<tr class="t-dsc">
<td colspan="2"> <div class="t-dsc-see"><span><a href="../../cpp/numeric/fenv.html" title="cpp/numeric/fenv">C++ documentation</a></span> for <span class="t-dsc-see-tt"><span>Floating-point environment</span></span></div>
</td></tr>
</table></div>
<!--
NewPP limit report
Preprocessor visited node count: 2879/1000000
Preprocessor generated node count: 5223/1000000
Post‐expand include size: 113158/2097152 bytes
Template argument size: 21154/2097152 bytes
Highest expansion depth: 20/40
Expensive parser function count: 0/100
-->
<!-- Saved in parser cache with key mwiki1-mwiki_en_:pcache:idhash:6421-0!*!0!!en!*!* and timestamp 20150825005416 -->
</div> <!-- /bodycontent -->
<!-- printfooter -->
<div class="printfooter">
Retrieved from "<a href="http://en.cppreference.com/mwiki/index.php?title=c/numeric/fenv&oldid=78965">http://en.cppreference.com/mwiki/index.php?title=c/numeric/fenv&oldid=78965</a>" </div>
<!-- /printfooter -->
<!-- catlinks -->
<div id='catlinks' class='catlinks catlinks-allhidden'></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="fenv.html#"></a></h5>
<ul>
<li id="t-whatlinkshere"><a href="http://en.cppreference.com/w/Special:WhatLinksHere/c/numeric/fenv" 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/c/numeric/fenv" 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=c/numeric/fenv&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=c/numeric/fenv&oldid=78965" 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=c/numeric/fenv&action=info">Page information</a></li> </ul>
</div>
<div id="cpp-languages">
<div><ul><li>In other languages</li></ul></div>
<div><ul>
<li class="interwiki-ar"><a href="http://ar.cppreference.com/w/c/numeric/fenv" title="c/numeric/fenv" lang="ar" hreflang="ar">العربية</a></li><li class="interwiki-cs"><a href="http://cs.cppreference.com/w/c/numeric/fenv" title="c/numeric/fenv" lang="cs" hreflang="cs">Česky</a></li><li class="interwiki-de"><a href="http://de.cppreference.com/w/c/numeric/fenv" title="c/numeric/fenv" lang="de" hreflang="de">Deutsch</a></li><li class="interwiki-es"><a href="http://es.cppreference.com/w/c/numeric/fenv" title="c/numeric/fenv" lang="es" hreflang="es">Español</a></li><li class="interwiki-fr"><a href="http://fr.cppreference.com/w/c/numeric/fenv" title="c/numeric/fenv" lang="fr" hreflang="fr">Français</a></li><li class="interwiki-it"><a href="http://it.cppreference.com/w/c/numeric/fenv" title="c/numeric/fenv" lang="it" hreflang="it">Italiano</a></li><li class="interwiki-ja"><a href="http://ja.cppreference.com/w/c/numeric/fenv" title="c/numeric/fenv" lang="ja" hreflang="ja">日本語</a></li><li class="interwiki-ko"><a href="http://ko.cppreference.com/w/c/numeric/fenv" title="c/numeric/fenv" lang="ko" hreflang="ko">한국어</a></li><li class="interwiki-pl"><a href="http://pl.cppreference.com/w/c/numeric/fenv" title="c/numeric/fenv" lang="pl" hreflang="pl">Polski</a></li><li class="interwiki-pt"><a href="http://pt.cppreference.com/w/c/numeric/fenv" title="c/numeric/fenv" lang="pt" hreflang="pt">Português</a></li><li class="interwiki-ru"><a href="http://ru.cppreference.com/w/c/numeric/fenv" title="c/numeric/fenv" lang="ru" hreflang="ru">Русский</a></li><li class="interwiki-tr"><a href="http://tr.cppreference.com/w/c/numeric/fenv" title="c/numeric/fenv" lang="tr" hreflang="tr">Türkçe</a></li><li class="interwiki-zh"><a href="http://zh.cppreference.com/w/c/numeric/fenv" title="c/numeric/fenv" lang="zh" hreflang="zh">中文</a></li> </ul></div>
</div>
<ul id="footer-info">
<li id="footer-info-lastmod"> This page was last modified on 13 June 2015, at 04:55.</li>
<li id="footer-info-viewcount">This page has been accessed 14,507 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 0.810 secs. -->
</body>
<!-- Cached 20150825005417 -->
</html>
|
