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
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
<title>Posix Time</title>
<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset">
<link rel="up" href="../date_time.html" title="Chapter 11. Boost.Date_Time">
<link rel="prev" href="gregorian.html" title="Gregorian">
<link rel="next" href="local_time.html" title="Local Time">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table cellpadding="2" width="100%"><tr>
<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../boost.png"></td>
<td align="center"><a href="../../../index.html">Home</a></td>
<td align="center"><a href="../../../libs/libraries.htm">Libraries</a></td>
<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
<td align="center"><a href="../../../more/index.htm">More</a></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="gregorian.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../date_time.html"><img src="../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="local_time.html"><img src="../../../doc/src/images/next.png" alt="Next"></a>
</div>
<div class="section">
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="date_time.posix_time"></a>Posix Time</h2></div></div></div>
<div class="toc"><dl class="toc">
<dt><span class="section"><a href="posix_time.html#date_time.posix_time.ptime_class">Ptime</a></span></dt>
<dt><span class="section"><a href="posix_time.html#date_time.posix_time.time_duration">Time Duration</a></span></dt>
<dt><span class="section"><a href="posix_time.html#date_time.posix_time.time_period">Time Period</a></span></dt>
<dt><span class="section"><a href="posix_time.html#date_time.posix_time.time_iterators">Time Iterators</a></span></dt>
</dl></div>
<h3>
<a name="idp205915264"></a>Posix Time System</h3>
<p>
<a class="link" href="posix_time.html#posix_intro">Introduction</a> --
<a class="link" href="posix_time.html#posix_ex">Usage Examples</a>
</p>
<a name="posix_intro"></a><h4>
<a name="idp205919024"></a>Introduction</h4>
<p>
Defines a non-adjusted time system with nano-second/micro-second resolution and stable calculation properties. The nano-second resolution option uses 96 bits of underlying storage for each ptime while the micro-second resolution uses 64 bits per ptime (see <a class="link" href="details.html#date_time.buildinfo" title="Build-Compiler Information">Build Options</a> for details). This time system uses the Gregorian calendar to implement the date portion of the time representation.
</p>
<a name="posix_ex"></a><h4>
<a name="idp205922176"></a>Usage Examples</h4>
<p>
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead><tr>
<th>Example</th>
<th>Description</th>
</tr></thead>
<tbody>
<tr>
<td><a class="link" href="examples.html#date_time.examples.time_math" title="Time Math">Time Math</a></td>
<td>A few simple calculations using ptime and time_durations.</td>
</tr>
<tr>
<td><a class="link" href="examples.html#date_time.examples.print_hours" title="Print Hours">Print Hours</a></td>
<td>Retrieve time from clock, use a time_iterator.</td>
</tr>
<tr>
<td><a class="link" href="examples.html#date_time.examples.local_utc_conversion" title="Local to UTC Conversion">Local to UTC Conversion</a></td>
<td>Demonstrates a couple different ways to convert a local to UTC time including daylight savings rules.</td>
</tr>
<tr>
<td><a class="link" href="examples.html#date_time.examples.time_periods" title="Time Periods">Time Periods</a></td>
<td>Some simple examples of intersection and display of time periods.</td>
</tr>
</tbody>
</table></div>
<p>
</p>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="date_time.posix_time.ptime_class"></a>Ptime</h3></div></div></div>
<a class="link" href="posix_time.html#ptime_intro">Introduction</a> --
<a class="link" href="posix_time.html#ptime_header">Header</a> --
<a class="link" href="posix_time.html#ptime_constr">Construction</a> --
<a class="link" href="posix_time.html#ptime_from_string">Construct from String</a> --
<a class="link" href="posix_time.html#ptime_from_clock">Construct from Clock</a> --
<a class="link" href="posix_time.html#ptime_from_funcs">Construct using Conversion functions</a> --
<a class="link" href="posix_time.html#ptime_accessors">Accessors</a> --
<a class="link" href="posix_time.html#ptime_to_string">Conversion To String</a> --
<a class="link" href="posix_time.html#ptime_operators">Operators</a> --
<a class="link" href="posix_time.html#ptime_struct_tm">Struct tm, time_t, and FILETIME Functions</a><a name="ptime_intro"></a><h4>
<a name="idp205946176"></a>Introduction</h4>
<p>
The class boost::posix_time::ptime is the primary interface for time point manipulation. In general, the ptime class is immutable once constructed although it does allow assignment.
</p>
<p>
Class ptime is dependent on <a class="link" href="gregorian.html#date_time.gregorian.date_class" title="Date">gregorian::date</a> for the interface to the date portion of a time point.
</p>
<p>
Other techniques for creating times include <a class="link" href="posix_time.html#date_time.posix_time.time_iterators" title="Time Iterators">time iterators</a>.
</p>
<a name="ptime_header"></a><h4>
<a name="idp205951024"></a>Header</h4>
<p>
</p>
<pre class="programlisting">#include "boost/date_time/posix_time/posix_time.hpp" //include all types plus i/o
or
#include "boost/date_time/posix_time/posix_time_types.hpp" //no i/o just types</pre>
<p>
</p>
<a name="ptime_constr"></a><h4>
<a name="idp205953616"></a>Construction</h4>
<p>
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Syntax</th>
<th>Description</th>
</tr>
<tr><th>Example</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime(date,time_duration)</pre></td>
<td>Construct from a date and offset</td>
</tr>
<tr><td>
<pre class="screen">ptime t1(date(2002,Jan,10),
time_duration(1,2,3));
ptime t2(date(2002,Jan,10),
hours(1)+nanosec(5));</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime(ptime)</pre></td>
<td>Copy constructor</td>
</tr>
<tr><td><pre class="screen">ptime t3(t1)</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime(special_values sv)</pre></td>
<td>Constructor for infinities, not-a-date-time, max_date_time, and min_date_time</td>
</tr>
<tr><td><pre class="screen">ptime d1(neg_infin);
ptime d2(pos_infin);
ptime d3(not_a_date_time);
ptime d4(max_date_time);
ptime d5(min_date_time);</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime;</pre></td>
<td>Default constructor. Creates a ptime object initialized to not_a_date_time. NOTE: this constructor can be disabled by defining DATE_TIME_NO_DEFAULT_CONSTRUCTOR (see compiler_config.hpp)</td>
</tr>
<tr><td><pre class="screen">ptime p; // p => not_a_date_time</pre></td></tr>
</tbody>
</table></div>
<p>
</p>
<a name="ptime_from_string"></a><h4>
<a name="idp205973824"></a>Construct from String</h4>
<p>
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Syntax</th>
<th>Description</th>
</tr>
<tr><th>Example</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime time_from_string(std::string)</pre></td>
<td>From delimited string. NOTE: Excess digits in fractional seconds will be dropped. Ex: "1:02:03.123456999" => 1:02:03.123456. This behavior is affected by the precision the library is compiled with (see <a class="link" href="details.html#date_time.buildinfo" title="Build-Compiler Information">Build-Compiler Information</a>.</td>
</tr>
<tr><td><pre class="screen">std::string ts("2002-01-20 23:59:59.000");
ptime t(time_from_string(ts))</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime from_iso_string(std::string)</pre></td>
<td>From non delimited iso form string.</td>
</tr>
<tr><td><pre class="screen">std::string ts("20020131T235959");
ptime t(from_iso_string(ts))</pre></td></tr>
</tbody>
</table></div>
<p>
</p>
<a name="ptime_from_clock"></a><h4>
<a name="idp205987872"></a>Construct from Clock</h4>
<p>
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Syntax</th>
<th>Description</th>
</tr>
<tr><th>Example</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime second_clock::local_time()</pre></td>
<td>Get the local time, second level resolution, based on the time zone settings of the computer.</td>
</tr>
<tr><td><pre class="screen">ptime t(second_clock::local_time());</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime second_clock::universal_time()</pre></td>
<td>Get the UTC time.</td>
</tr>
<tr><td><pre class="screen">ptime t(second_clock::universal_time())</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime microsec_clock::local_time()</pre></td>
<td>Get the local time using a sub second resolution clock. On Unix systems this is implemented using GetTimeOfDay. On most Win32 platforms it is implemented using ftime. Win32 systems often do not achieve microsecond resolution via this API. If higher resolution is critical to your application test your platform to see the achieved resolution.</td>
</tr>
<tr><td><pre class="screen">ptime t(microsec_clock::local_time());</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime microsec_clock::universal_time()</pre></td>
<td>Get the UTC time using a sub second resolution clock. On Unix systems this is implemented using GetTimeOfDay. On most Win32 platforms it is implemented using ftime. Win32 systems often do not achieve microsecond resolution via this API. If higher resolution is critical to your application test your platform to see the achieved resolution.</td>
</tr>
<tr><td><pre class="screen">ptime t(microsec_clock::universal_time());</pre></td></tr>
</tbody>
</table></div>
<p>
</p>
<a name="ptime_from_funcs"></a><h4>
<a name="idp206008560"></a>Construct using Conversion Functions</h4>
<p>
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Syntax</th>
<th>Description</th>
</tr>
<tr><th>Example</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime from_time_t(time_t t);</pre></td>
<td>Converts a time_t into a ptime.</td>
</tr>
<tr><td><pre class="screen">ptime t = from_time_t(tt);</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime from_ftime<ptime>(FILETIME ft);</pre></td>
<td>Creates a ptime object from a FILETIME structure.</td>
</tr>
<tr><td><pre class="screen">ptime t = from_ftime<ptime>(ft);</pre></td></tr>
</tbody>
</table></div>
<p>
</p>
<a name="ptime_accessors"></a><h4>
<a name="idp206021632"></a>Accessors</h4>
<p>
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Syntax</th>
<th>Description</th>
</tr>
<tr><th>Example</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top"><pre class="screen">date date()</pre></td>
<td>Get the date part of a time.</td>
</tr>
<tr><td>
<pre class="screen">date d(2002,Jan,10);
ptime t(d, hour(1));
t.date() --> 2002-Jan-10;</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_duration time_of_day()</pre></td>
<td>Get the time offset in the day.</td>
</tr>
<tr><td>
<pre class="screen">date d(2002,Jan,10);
ptime t(d, hour(1));
t.time_of_day() --> 01:00:00;</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">bool is_infinity() const</pre></td>
<td>Returns true if ptime is either positive or negative infinity</td>
</tr>
<tr><td><pre class="screen">ptime pt(pos_infin);
pt.is_infinity(); // --> true</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">bool is_neg_infinity() const</pre></td>
<td>Returns true if ptime is negative infinity</td>
</tr>
<tr><td><pre class="screen">ptime pt(neg_infin);
pt.is_neg_infinity(); // --> true</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">bool is_pos_infinity() const</pre></td>
<td>Returns true if ptime is positive infinity</td>
</tr>
<tr><td><pre class="screen">ptime pt(neg_infin);
pt.is_pos_infinity(); // --> true</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">bool is_not_a_date_time() const</pre></td>
<td>Returns true if value is not a ptime</td>
</tr>
<tr><td><pre class="screen">ptime pt(not_a_date_time);
pt.is_not_a_date_time(); // --> true</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">bool is_special() const</pre></td>
<td>Returns true if ptime is any <code class="computeroutput">special_value</code>
</td>
</tr>
<tr><td><pre class="screen">ptime pt(pos_infin);
ptime pt2(not_a_date_time);
ptime pt3(date(2005,Mar,1), hours(10));
pt.is_special(); // --> true
pt2.is_special(); // --> true
pt3.is_special(); // --> false</pre></td></tr>
</tbody>
</table></div>
<p>
</p>
<a name="ptime_to_string"></a><h4>
<a name="idp206052736"></a>Conversion to String</h4>
<p>
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Syntax</th>
<th>Description</th>
</tr>
<tr><th>Example</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top"><pre class="screen">std::string to_simple_string(ptime)</pre></td>
<td>To <code class="computeroutput">YYYY-mmm-DD HH:MM:SS.fffffffff</code> string where <code class="computeroutput">mmm</code> 3 char month name. Fractional seconds only included if non-zero.</td>
</tr>
<tr><td><pre class="screen">2002-Jan-01 10:00:01.123456789</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">std::string to_iso_string(ptime)</pre></td>
<td>Convert to form <code class="computeroutput">YYYYMMDDTHHMMSS,fffffffff</code> where <code class="computeroutput">T</code> is the date-time separator</td>
</tr>
<tr><td><pre class="screen">20020131T100001,123456789</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">std::string to_iso_extended_string(ptime)</pre></td>
<td>Convert to form <code class="computeroutput">YYYY-MM-DDTHH:MM:SS,fffffffff</code> where <code class="computeroutput">T</code> is the date-time separator</td>
</tr>
<tr><td><pre class="screen">2002-01-31T10:00:01,123456789</pre></td></tr>
</tbody>
</table></div>
<p>
</p>
<a name="ptime_operators"></a><h4>
<a name="idp206073328"></a>Operators</h4>
<p>
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Syntax</th>
<th>Description</th>
</tr>
<tr><th>Example</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top"><pre class="screen">operator<<, operator>></pre></td>
<td>Streaming operators. <span class="strong"><strong>Note:</strong></span> As of version 1.33, streaming operations have been greatly improved. See <a class="link" href="date_time_io.html" title="Date Time Input/Output">Date Time IO System</a> for more details (including exceptions and error conditions).</td>
</tr>
<tr><td>
<pre class="screen">ptime pt(not_a_date_time);
stringstream ss("2002-Jan-01 14:23:11");
ss >> pt;
std::cout << pt; // "2002-Jan-01 14:23:11"
</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top">
<pre class="screen">operator==, operator!=,
operator>, operator<,
operator>=, operator<=</pre>
</td>
<td>A full complement of comparison operators</td>
</tr>
<tr><td><pre class="screen">t1 == t2, etc</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime operator+(days)</pre></td>
<td>Return a ptime adding a day offset</td>
</tr>
<tr><td>
<pre class="screen">date d(2002,Jan,1);
ptime t(d,minutes(5));
days dd(1);
ptime t2 = t + dd;</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime operator-(days)</pre></td>
<td>Return a ptime subtracting a day offset</td>
</tr>
<tr><td>
<pre class="screen">date d(2002,Jan,1);
ptime t(d,minutes(5));
days dd(1);
ptime t2 = t - dd;</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime operator+(time_duration)</pre></td>
<td>Return a ptime adding a time duration</td>
</tr>
<tr><td>
<pre class="screen">date d(2002,Jan,1);
ptime t(d,minutes(5));
ptime t2 = t + hours(1) + minutes(2);</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime operator-(time_duration)</pre></td>
<td>Return a ptime subtracting a time duration</td>
</tr>
<tr><td>
<pre class="screen">date d(2002,Jan,1);
ptime t(d,minutes(5));
ptime t2 = t - minutes(2);</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_duration operator-(ptime)</pre></td>
<td>Take the difference between two times.</td>
</tr>
<tr><td>
<pre class="screen">date d(2002,Jan,1);
ptime t1(d,minutes(5));
ptime t2(d,seconds(5));
time_duration t3 = t2 - t1;//negative result</pre>
</td></tr>
</tbody>
</table></div>
<p>
</p>
<a name="ptime_struct_tm"></a><h4>
<a name="idp206106048"></a>Struct tm, time_t, and FILETIME Functions</h4>
<p>Functions for converting posix_time objects to, and from, <code class="computeroutput">tm</code> structs are provided as well as conversion from <code class="computeroutput">time_t</code> and <code class="computeroutput">FILETIME</code>.</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Syntax</th>
<th>Description</th>
</tr>
<tr><th>Example</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top"><pre class="screen">tm to_tm(ptime)</pre></td>
<td>A function for converting a <code class="computeroutput">ptime</code> object to a <code class="computeroutput">tm</code> struct. The <code class="computeroutput">tm_isdst</code> field is set to -1.</td>
</tr>
<tr><td>
<pre class="screen">ptime pt(date(2005,Jan,1), time_duration(1,2,3));
tm pt_tm = to_tm(pt);
/* tm_year => 105
tm_mon => 0
tm_mday => 1
tm_wday => 6 (Saturday)
tm_yday => 0
tm_hour => 1
tm_min => 2
tm_sec => 3
tm_isddst => -1 */</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime ptime_from_tm(tm timetm)</pre></td>
<td>A function for converting a <code class="computeroutput">tm</code> struct to a <code class="computeroutput">ptime</code> object. The fields: <code class="computeroutput">tm_wday </code>, <code class="computeroutput">tm_yday </code>, and <code class="computeroutput">tm_isdst</code> are ignored.</td>
</tr>
<tr><td>
<pre class="screen">tm pt_tm;
pt_tm.tm_year = 105;
pt_tm.tm_mon = 0;
pt_tm.tm_mday = 1;
pt_tm.tm_hour = 1;
pt_tm.tm_min = 2;
pt_tm.tm_sec = 3;
ptime pt = ptime_from_tm(pt_tm);
// pt => 2005-Jan-01 01:02:03</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">tm to_tm(time_duration)</pre></td>
<td>A function for converting a <code class="computeroutput">time_duration</code> object to a <code class="computeroutput">tm</code> struct. The fields: <code class="computeroutput">tm_year</code>, <code class="computeroutput">tm_mon</code>, <code class="computeroutput">tm_mday</code>, <code class="computeroutput">tm_wday</code>, <code class="computeroutput">tm_yday</code> are set to zero. The <code class="computeroutput">tm_isdst</code> field is set to -1.</td>
</tr>
<tr><td>
<pre class="screen">time_duration td(1,2,3);
tm td_tm = to_tm(td);
/* tm_year => 0
tm_mon => 0
tm_mday => 0
tm_wday => 0
tm_yday => 0
tm_hour => 1
tm_min => 2
tm_sec => 3
tm_isddst => -1 */</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime from_time_t(std::time_t)</pre></td>
<td>Creates a <code class="computeroutput">ptime</code> from the time_t parameter. The seconds held in the time_t are added to a time point of 1970-Jan-01.</td>
</tr>
<tr><td><pre class="screen">ptime pt(not_a_date_time);
std::time_t t;
t = 1118158776;
pt = from_time_t(t);
// pt => 2005-Jun-07 15:39:36</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime from_ftime<ptime>(FILETIME)</pre></td>
<td>A template function that constructs a <code class="computeroutput">ptime</code> from a FILETIME struct.</td>
</tr>
<tr><td><pre class="screen">FILETIME ft;
ft.dwHighDateTime = 29715317;
ft.dwLowDateTime = 3865122988UL;
ptime pt = from_ftime<ptime>(ft);
// pt => 2005-Jun-07 15:30:57.039582000</pre></td></tr>
</tbody>
</table></div>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="date_time.posix_time.time_duration"></a>Time Duration</h3></div></div></div>
<a class="link" href="posix_time.html#time_duration_intro">Introduction</a> --
<a class="link" href="posix_time.html#time_duration_header">Header</a> --
<a class="link" href="posix_time.html#time_duration_constr">Construction</a> --
<a class="link" href="posix_time.html#time_duration_count_constr">Count Based Construction</a> --
<a class="link" href="posix_time.html#time_duration_from_string">Construct from String</a> --
<a class="link" href="posix_time.html#time_duration_accessors">Accessors</a> --
<a class="link" href="posix_time.html#time_duration_to_string">Conversion To String</a> --
<a class="link" href="posix_time.html#time_duration_operators">Operators</a> --
<a class="link" href="posix_time.html#time_duration_struct_tm">Struct tm Functions</a><a name="time_duration_intro"></a><h4>
<a name="idp206155936"></a>Introduction</h4>
<p>
The class boost::posix_time::time_duration the base type responsible for representing a length of time. A duration can be either positive or negative. The general time_duration class provides a constructor that takes a count of the number of hours, minutes, seconds, and fractional seconds count as shown in the code fragment below. The resolution of the time_duration is configure able at compile time. See <a class="link" href="details.html#date_time.buildinfo" title="Build-Compiler Information">Build-Compiler Information</a> for more information.
</p>
<p>
</p>
<pre class="programlisting">using namespace boost::posix_time;
time_duration td(1,2,3,4); //01:02:03.000000004 when resolution is nano seconds
time_duration td(1,2,3,4); //01:02:03.000004 when resolution is micro seconds</pre>
<p>
</p>
<p>
Several small helper classes that derive from a base time_duration, as shown below, to adjust for different resolutions. These classes can shorten code and make the intent clearer.
</p>
<img src="../../../libs/date_time/doc/time_duration_inherit.png"><p>
As an example:
</p>
<pre class="programlisting">using namespace boost::posix_time;
time_duration td = hours(1) + seconds(10); //01:00:01
td = hours(1) + nanoseconds(5); //01:00:00.000000005</pre>
<p>
Note that the existence of the higher resolution classes (eg: nanoseconds) depends on the installation of the library. See <a class="link" href="details.html#date_time.buildinfo" title="Build-Compiler Information">Build-Compiler Information</a> for more information.
</p>
<p>
Another way to handle this is to utilize the ticks_per_second() method of time_duration to
write code that is portable no matter how the library is compiled. The general equation
for calculating a resolution independent count is as follows:
</p>
<pre class="programlisting">
count*(time_duration_ticks_per_second / count_ticks_per_second)
</pre>
<p>
For example, let's suppose we want to construct using a count that represents tenths
of a second. That is, each tick is 0.1 second.
</p>
<pre class="programlisting">
int number_of_tenths = 5;
//create a resolution independent count -- divide by 10 since there are
//10 tenths in a second.
int count = number_of_tenths*(time_duration::ticks_per_second()/10);
time_duration td(1,2,3,count); //01:02:03.5 //no matter the resolution settings
</pre>
<p>
</p>
<a name="time_duration_header"></a><h4>
<a name="idp206166176"></a>Header</h4>
<p>
</p>
<pre class="programlisting">#include "boost/date_time/posix_time/posix_time.hpp" //include all types plus i/o
or
#include "boost/date_time/posix_time/posix_time_types.hpp" //no i/o just types</pre>
<p>
</p>
<a name="time_duration_constr"></a><h4>
<a name="idp206168768"></a>Construction</h4>
<p>
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Syntax</th>
<th>Description</th>
</tr>
<tr><th>Example</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_duration(hours,
minutes,
seconds,
fractional_seconds)</pre></td>
<td>Construct a duration from the counts. The fractional_second parameter is a number of units and is therefore affected by the resolution the application is compiled with (see <a class="link" href="details.html#compile_options">Build-Compiler Information</a>). If the fractional_seconds argument exceeds the limit of the compiled precision, the excess value will be "carried over" into the seconds field. See above for techniques to creating a resolution independent count.</td>
</tr>
<tr><td><pre class="screen">time_duration td(1,2,3,9);
//1 hr 2 min 3 sec 9 nanoseconds
time_duration td2(1,2,3,123456789);
time_duration td3(1,2,3,1000);
// with microsecond resolution (6 digits)
// td2 => "01:04:06.456789"
// td3 => "01:02:03.001000"
// with nanosecond resolution (9 digits)
// td2 => "01:02:03.123456789"
// td3 => "01:02:03.000001000"</pre></td></tr>
<tr>
<td valign="top"><pre class="screen">time_duration(special_value sv)</pre></td>
<td>Special values constructor. <span class="strong"><strong>Important note</strong></span>: When a time_duration is a special value, either by construction or other means, the following accessor functions will give unpredictable results: <pre class="screen">hours(), minutes(), seconds(), ticks(),
fractional_seconds(), total_nanoseconds(),
total_microseconds(), total_milliseconds(),
total_seconds()</pre>The remaining accessor functions will work as expected.</td>
</tr>
</tbody>
</table></div>
<p>
</p>
<a name="time_duration_count_constr"></a><h4>
<a name="idp206183808"></a>Count Based Construction</h4>
<p>
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Syntax</th>
<th>Description</th>
</tr>
<tr><th>Example</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top"><pre class="screen">hours(long)</pre></td>
<td>Number of hours</td>
</tr>
<tr><td><pre class="screen">time_duration td = hours(3);</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">minutes(long)</pre></td>
<td>Number of minutes</td>
</tr>
<tr><td><pre class="screen">time_duration td = minutes(3);</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">seconds(long)</pre></td>
<td> Number of seconds</td>
</tr>
<tr><td><pre class="screen">time_duration td = seconds(3);</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">milliseconds(long)</pre></td>
<td>Number of milliseconds.</td>
</tr>
<tr><td><pre class="screen">time_duration td = milliseconds(3);</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">microseconds(long)</pre></td>
<td>Number of microseconds.</td>
</tr>
<tr><td><pre class="screen">time_duration td = microseconds(3);</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">nanoseconds(long)</pre></td>
<td>Number of nanoseconds.</td>
</tr>
<tr><td><pre class="screen">time_duration td = nanoseconds(3);</pre></td></tr>
</tbody>
</table></div>
<p>
</p>
<a name="time_duration_from_string"></a><h4>
<a name="idp206210000"></a>Construct from String</h4>
<p>
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Syntax</th>
<th>Description</th>
</tr>
<tr><th>Example</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_duration duration_from_string(std::string)</pre></td>
<td>From delimited string. NOTE: Excess digits in fractional seconds will be dropped. Ex: "1:02:03.123456999" => 1:02:03.123456. This behavior is affected by the precision the library is compiled with (see <a class="link" href="details.html#date_time.buildinfo" title="Build-Compiler Information">Build-Compiler Information</a>.</td>
</tr>
<tr><td>
<pre class="screen">std::string ts("23:59:59.000");
time_duration td(duration_from_string(ts));</pre>
</td></tr>
</tbody>
</table></div>
<p>
</p>
<a name="time_duration_accessors"></a><h4>
<a name="idp206220800"></a>Accessors</h4>
<p>
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Syntax</th>
<th>Description</th>
</tr>
<tr><th>Example</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top"><pre class="screen">long hours()</pre></td>
<td>Get the number of normalized hours (will give unpredictable results if calling <code class="computeroutput">time_duration</code> is a <code class="computeroutput">special_value</code>).</td>
</tr>
<tr><td><pre class="screen">time_duration td(1,2,3);
time_duration neg_td(-1,2,3);
td.hours(); // --> 1
neg_td.hours(); // --> -1</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">long minutes()</pre></td>
<td>Get the number of minutes normalized +/-(0..59) (will give unpredictable results if calling <code class="computeroutput">time_duration</code> is a <code class="computeroutput">special_value</code>).</td>
</tr>
<tr><td><pre class="screen">time_duration td(1,2,3);
time_duration neg_td(-1,2,3);
td.minutes(); // --> 2
neg_td.minutes(); // --> -2</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">long seconds()</pre></td>
<td>Get the normalized number of second +/-(0..59) (will give unpredictable results if calling <code class="computeroutput">time_duration</code> is a <code class="computeroutput">special_value</code>).</td>
</tr>
<tr><td><pre class="screen">time_duration td(1,2,3);
time_duration neg_td(-1,2,3);
td.seconds(); // --> 3
neg_td.seconds(); // --> -3</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">long total_seconds()</pre></td>
<td>Get the total number of seconds truncating any fractional seconds (will give unpredictable results if calling <code class="computeroutput">time_duration</code> is a <code class="computeroutput">special_value</code>).</td>
</tr>
<tr><td>
<pre class="screen">time_duration td(1,2,3,10);
td.total_seconds();
// --> (1*3600) + (2*60) + 3 == 3723</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">long total_milliseconds()</pre></td>
<td>Get the total number of milliseconds truncating any remaining digits (will give unpredictable results if calling <code class="computeroutput">time_duration</code> is a <code class="computeroutput">special_value</code>).</td>
</tr>
<tr><td>
<pre class="screen">time_duration td(1,2,3,123456789);
td.total_milliseconds();
// HMS --> (1*3600) + (2*60) + 3 == 3723 seconds
// milliseconds is 3 decimal places
// (3723 * 1000) + 123 == 3723123</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">long total_microseconds()</pre></td>
<td>Get the total number of microseconds truncating any remaining digits (will give unpredictable results if calling <code class="computeroutput">time_duration</code> is a <code class="computeroutput">special_value</code>).</td>
</tr>
<tr><td>
<pre class="screen">time_duration td(1,2,3,123456789);
td.total_microseconds();
// HMS --> (1*3600) + (2*60) + 3 == 3723 seconds
// microseconds is 6 decimal places
// (3723 * 1000000) + 123456 == 3723123456</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">long total_nanoseconds()</pre></td>
<td>Get the total number of nanoseconds truncating any remaining digits (will give unpredictable results if calling <code class="computeroutput">time_duration</code> is a <code class="computeroutput">special_value</code>).</td>
</tr>
<tr><td>
<pre class="screen">time_duration td(1,2,3,123456789);
td.total_nanoseconds();
// HMS --> (1*3600) + (2*60) + 3 == 3723 seconds
// nanoseconds is 9 decimal places
// (3723 * 1000000000) + 123456789
// == 3723123456789</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">long fractional_seconds()</pre></td>
<td>Get the number of fractional seconds (will give unpredictable results if calling <code class="computeroutput">time_duration</code> is a <code class="computeroutput">special_value</code>).</td>
</tr>
<tr><td><pre class="screen">time_duration td(1,2,3, 1000);
td.fractional_seconds(); // --> 1000</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">bool is_negative()</pre></td>
<td>True if duration is negative.</td>
</tr>
<tr><td><pre class="screen">time_duration td(-1,0,0);
td.is_negative(); // --> true</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_duration invert_sign()</pre></td>
<td>Generate a new duration with the sign inverted/</td>
</tr>
<tr><td><pre class="screen">time_duration td(-1,0,0);
td.invert_sign(); // --> 01:00:00</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">date_time::time_resolutions resolution()</pre></td>
<td>Describes the resolution capability of the time_duration class. time_resolutions is an enum of resolution possibilities ranging from seconds to nanoseconds.</td>
</tr>
<tr><td><pre class="screen">time_duration::resolution() --> nano</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_duration::num_fractional_digits()</pre></td>
<td>Returns an unsigned short holding the number of fractional digits the time resolution has.</td>
</tr>
<tr><td><pre class="screen">unsigned short secs;
secs = time_duration::num_fractional_digits();
// 9 for nano, 6 for micro, etc.</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_duration::ticks_per_second()</pre></td>
<td>Return the number of ticks in a second. For example, if the duration supports nanoseconds then the returned result will be 1,000,000,000 (1e+9).</td>
</tr>
<tr><td><pre class="screen">std::cout << time_duration::ticks_per_second();</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">boost::int64_t ticks()</pre></td>
<td>Return the raw count of the duration type (will give unpredictable results if calling <code class="computeroutput">time_duration</code> is a <code class="computeroutput">special_value</code>).</td>
</tr>
<tr><td><pre class="screen">time_duration td(0,0,0, 1000);
td.ticks() // --> 1000</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_duration unit()</pre></td>
<td>Return smallest possible unit of duration type (1 nanosecond).</td>
</tr>
<tr><td><pre class="screen">time_duration::unit() --> time_duration(0,0,0,1)</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">bool is_neg_infinity() const</pre></td>
<td>Returns true if time_duration is negative infinity</td>
</tr>
<tr><td><pre class="screen">time_duration td(neg_infin);
td.is_neg_infinity(); // --> true</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">bool is_pos_infinity() const</pre></td>
<td>Returns true if time_duration is positive infinity</td>
</tr>
<tr><td><pre class="screen">time_duration td(pos_infin);
td.is_pos_infinity(); // --> true</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">bool is_not_a_date_time() const</pre></td>
<td>Returns true if value is not a time</td>
</tr>
<tr><td><pre class="screen">time_duration td(not_a_date_time);
td.is_not_a_date_time(); // --> true</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">bool is_special() const</pre></td>
<td>Returns true if time_duration is any <code class="computeroutput">special_value</code>
</td>
</tr>
<tr><td><pre class="screen">time_duration td(pos_infin);
time_duration td2(not_a_date_time);
time_duration td3(2,5,10);
td.is_special(); // --> true
td2.is_special(); // --> true
td3.is_special(); // --> false</pre></td></tr>
</tbody>
</table></div>
<p>
</p>
<a name="time_duration_to_string"></a><h4>
<a name="idp206308208"></a>Conversion To String</h4>
<p>
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Syntax</th>
<th>Description</th>
</tr>
<tr><th>Example</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top"><pre class="screen">std::string to_simple_string(time_duration)</pre></td>
<td>To <code class="computeroutput">HH:MM:SS.fffffffff</code> were <code class="computeroutput">fff</code> is fractional seconds that are only included if non-zero.</td>
</tr>
<tr><td><pre class="screen">10:00:01.123456789</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">std::string to_iso_string(time_duration)</pre></td>
<td>Convert to form <code class="computeroutput">HHMMSS,fffffffff</code>.</td>
</tr>
<tr><td><pre class="screen">100001,123456789</pre></td></tr>
</tbody>
</table></div>
<p>
</p>
<a name="time_duration_operators"></a><h4>
<a name="idp206323232"></a>Operators</h4>
<p>
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Syntax</th>
<th>Description</th>
</tr>
<tr><th>Example</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top"><pre class="screen">operator<<, operator>></pre></td>
<td>Streaming operators. <span class="strong"><strong>Note:</strong></span> As of version 1.33, streaming operations have been greatly improved. See <a class="link" href="date_time_io.html" title="Date Time Input/Output">Date Time IO System</a> for more details (including exceptions and error conditions).</td>
</tr>
<tr><td>
<pre class="screen">time_duration td(0,0,0);
stringstream ss("14:23:11.345678");
ss >> td;
std::cout << td; // "14:23:11.345678"
</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top">
<pre class="screen">operator==, operator!=,
operator>, operator<,
operator>=, operator<=</pre>
</td>
<td>A full complement of comparison operators</td>
</tr>
<tr><td><pre class="screen">dd1 == dd2, etc</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_duration operator+(time_duration)</pre></td>
<td>Add durations.</td>
</tr>
<tr><td>
<pre class="screen">time_duration td1(hours(1)+minutes(2));
time_duration td2(seconds(10));
time_duration td3 = td1 + td2;</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_duration operator-(time_duration)</pre></td>
<td>Subtract durations.</td>
</tr>
<tr><td>
<pre class="screen">time_duration td1(hours(1)+nanoseconds(2));
time_duration td2 = td1 - minutes(1);</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_duration operator/(int)</pre></td>
<td>Divide the length of a duration by an integer value. Discards any remainder.</td>
</tr>
<tr><td>
<pre class="screen">hours(3)/2 == time_duration(1,30,0);
nanosecond(3)/2 == nanosecond(1);</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_duration operator*(int)</pre></td>
<td>Multiply the length of a duration by an integer value.</td>
</tr>
<tr><td><pre class="screen">hours(3)*2 == hours(6);</pre></td></tr>
</tbody>
</table></div>
<p>
</p>
<a name="time_duration_struct_tm"></a><h4>
<a name="idp206352256"></a>Struct tm, time_t, and FILETIME Functions</h4>
<p>Function for converting a time_duration to a <code class="computeroutput">tm</code> struct is provided.</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Syntax</th>
<th>Description</th>
</tr>
<tr><th>Example</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top"><pre class="screen">tm to_tm(time_duration)</pre></td>
<td>A function for converting a <code class="computeroutput">time_duration</code> object to a <code class="computeroutput">tm</code> struct. The fields: <code class="computeroutput">tm_year</code>, <code class="computeroutput">tm_mon</code>, <code class="computeroutput">tm_mday</code>, <code class="computeroutput">tm_wday</code>, <code class="computeroutput">tm_yday</code> are set to zero. The <code class="computeroutput">tm_isdst</code> field is set to -1.</td>
</tr>
<tr><td>
<pre class="screen">time_duration td(1,2,3);
tm td_tm = to_tm(td);
/* tm_year => 0
tm_mon => 0
tm_mday => 0
tm_wday => 0
tm_yday => 0
tm_hour => 1
tm_min => 2
tm_sec => 3
tm_isddst => -1 */</pre>
</td></tr>
</tbody>
</table></div>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="date_time.posix_time.time_period"></a>Time Period</h3></div></div></div>
<a class="link" href="posix_time.html#time_period_intro">Introduction</a> --
<a class="link" href="posix_time.html#time_period_header">Header</a> --
<a class="link" href="posix_time.html#time_period_constr">Construction</a> --
<a class="link" href="posix_time.html#time_period_mutators">Mutators</a> --
<a class="link" href="posix_time.html#time_period_accessors">Accessors</a> --
<a class="link" href="posix_time.html#time_period_to_string">Conversion To String</a> --
<a class="link" href="posix_time.html#time_period_operators">Operators</a><a name="time_period_intro"></a><h4>
<a name="idp206376880"></a>Introduction</h4>
<p>
The class boost::posix_time::time_period provides direct representation for ranges between two times. Periods provide the ability to simplify some types of calculations by simplifying the conditional logic of the program.
</p>
<p>
A period that is created with beginning and end points being equal, or with a duration of zero, is known as a zero length period. Zero length periods are considered invalid (it is perfectly legal to construct an invalid period). For these periods, the <code class="computeroutput">last</code> point will always be one unit less that the <code class="computeroutput">begin</code> point.
</p>
<p>
The <a class="link" href="examples.html#date_time.examples.time_periods" title="Time Periods">time periods example</a> provides an example of using time periods.
</p>
<a name="time_period_header"></a><h4>
<a name="idp206382368"></a>Header</h4>
<p>
</p>
<pre class="programlisting">#include "boost/date_time/posix_time/posix_time.hpp" //include all types plus i/o
or
#include "boost/date_time/posix_time/posix_time_types.hpp" //no i/o just types</pre>
<p>
</p>
<a name="time_period_constr"></a><h4>
<a name="idp206384960"></a>Construction</h4>
<p>
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Syntax</th>
<th>Description</th>
</tr>
<tr><th>Example</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_period(ptime,
ptime)</pre></td>
<td> Create a period as [begin, end). If end is <= begin then the period will be defined as invalid.</td>
</tr>
<tr><td>
<pre class="screen">date d(2002,Jan,01);
ptime t1(d, seconds(10)); //10 sec after midnight
ptime t2(d, hours(10)); //10 hours after midnight
time_period tp(t1, t2);</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_period(ptime,
time_duration)</pre></td>
<td> Create a period as [begin, begin+len) where end would be begin+len. If len is <= zero then the period will be defined as invalid.</td>
</tr>
<tr><td>
<pre class="screen">date d(2002,Jan,01);
ptime t(d, seconds(10)); //10 sec after midnight
time_period tp(t, hours(3));</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_period(time_period rhs)</pre></td>
<td> Copy constructor</td>
</tr>
<tr><td><pre class="screen">time_period tp1(tp);</pre></td></tr>
</tbody>
</table></div>
<p>
</p>
<a name="time_period_mutators"></a><h4>
<a name="idp206402016"></a>Mutators</h4>
<p>
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Syntax</th>
<th>Description</th>
</tr>
<tr><th>Example</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_period shift(time_duration)</pre></td>
<td>Add duration to both begin and end.</td>
</tr>
<tr><td>
<pre class="screen">
time_period tp(ptime(date(2005,Jan,1),hours(1)), hours(2));
tp.shift(minutes(5));
// tp == 2005-Jan-01 01:05:00 to 2005-Jan-01 03:05:00
</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_period expand(days)</pre></td>
<td>Subtract duration from begin and add duration to end.</td>
</tr>
<tr><td>
<pre class="screen">
time_period tp(ptime(date(2005,Jan,1),hours(1)), hours(2));
tp.expand(minutes(5));
// tp == 2005-Jan-01 00:55:00 to 2005-Jan-01 03:05:00
</pre>
</td></tr>
</tbody>
</table></div>
<p>
</p>
<a name="time_period_accessors"></a><h4>
<a name="idp206415680"></a>Accessors</h4>
<p>
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Syntax</th>
<th>Description</th>
</tr>
<tr><th>Example</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime begin()</pre></td>
<td>Return first time of period.</td>
</tr>
<tr><td>
<pre class="screen">date d(2002,Jan,01);
ptime t1(d, seconds(10)); //10 sec after midnight
ptime t2(d, hours(10)); //10 hours after midnight
time_period tp(t1, t2);
tp.begin(); // --> 2002-Jan-01 00:00:10</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime last()</pre></td>
<td>Return last time in the period</td>
</tr>
<tr><td>
<pre class="screen">date d(2002,Jan,01);
ptime t1(d, seconds(10)); //10 sec after midnight
ptime t2(d, hours(10)); //10 hours after midnight
time_period tp(t1, t2);
tp.last();// --> 2002-Jan-01 09:59:59.999999999</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">ptime end()</pre></td>
<td> Return one past the last in period</td>
</tr>
<tr><td>
<pre class="screen">date d(2002,Jan,01);
ptime t1(d, seconds(10)); //10 sec after midnight
ptime t2(d, hours(10)); //10 hours after midnight
time_period tp(t1, t2);
tp.last(); // --> 2002-Jan-01 10:00:00</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_duration length()</pre></td>
<td>Return the length of the time period.</td>
</tr>
<tr><td>
<pre class="screen">date d(2002,Jan,01);
ptime t1(d); //midnight
time_period tp(t1, hours(1));
tp.length() --> 1 hour</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">bool is_null()</pre></td>
<td>True if period is not well formed. eg: end is less than or equal to begin.</td>
</tr>
<tr><td>
<pre class="screen">date d(2002,Jan,01);
ptime t1(d, hours(12)); // noon on Jan 1st
ptime t2(d, hours(9)); // 9am on Jan 1st
time_period tp(t1, t2);
tp.is_null(); // true</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">bool contains(ptime)</pre></td>
<td>True if ptime is within the period. Zero length periods cannot contain any points.</td>
</tr>
<tr><td>
<pre class="screen">date d(2002,Jan,01);
ptime t1(d, seconds(10)); //10 sec after midnight
ptime t2(d, hours(10)); //10 hours after midnight
ptime t3(d, hours(2)); //2 hours after midnight
time_period tp(t1, t2);
tp.contains(t3); // true
time_period tp2(t1, t1);
tp2.contains(t1); // false</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">bool contains(time_period)</pre></td>
<td>True if period is within the period</td>
</tr>
<tr><td>
<pre class="screen">time_period tp1(ptime(d,hours(1)),
ptime(d,hours(12)));
time_period tp2(ptime(d,hours(2)),
ptime(d,hours(4)));
tp1.contains(tp2); // --> true
tp2.contains(tp1); // --> false</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">bool intersects(time_period)</pre></td>
<td> True if periods overlap</td>
</tr>
<tr><td>
<pre class="screen">time_period tp1(ptime(d,hours(1)),
ptime(d,hours(12)));
time_period tp2(ptime(d,hours(2)),
ptime(d,hours(4)));
tp2.intersects(tp1); // --> true</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_period intersection(time_period)</pre></td>
<td>Calculate the intersection of 2 periods. Null if no intersection.</td>
</tr>
<tr><td> </td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_period merge(time_period)</pre></td>
<td>Returns union of two periods. Null if no intersection.</td>
</tr>
<tr><td> </td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_period span(time_period)</pre></td>
<td>Combines two periods and any gap between them such that begin = min(p1.begin, p2.begin) and end = max(p1.end , p2.end).</td>
</tr>
<tr><td> </td></tr>
</tbody>
</table></div>
<p>
</p>
<a name="time_period_to_string"></a><h4>
<a name="idp206460176"></a>Conversion To String</h4>
<p>
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Syntax</th>
<th>Description</th>
</tr>
<tr><th>Example</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top"><pre class="screen">std::string
to_simple_string(time_period dp)</pre></td>
<td>To <code class="computeroutput">[YYYY-mmm-DD hh:mm:ss.fffffffff/YYYY-mmm-DD hh:mm:ss.fffffffff]</code> string where <code class="computeroutput">mmm</code> is 3 char month name.</td>
</tr>
<tr><td><pre class="screen">[2002-Jan-01 01:25:10.000000001/
2002-Jan-31 01:25:10.123456789]
// string occupies one line</pre></td></tr>
</tbody>
</table></div>
<p>
</p>
<a name="time_period_operators"></a><h4>
<a name="idp206471296"></a>Operators</h4>
<p>
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Syntax</th>
<th>Description</th>
</tr>
<tr><th>Example</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top"><pre class="screen">operator<<</pre></td>
<td>Output streaming operator for time duration. Uses facet to output [date time_of_day/date time_of_day]. The default is format is <code class="computeroutput">[YYYY-mmm-DD hh:mm:ss.fffffffff/YYYY-mmm-DD hh:mm:ss.fffffffff]</code> string where <code class="computeroutput">mmm</code> is 3 char month name and the fractional seconds are left out when zero.</td>
</tr>
<tr><td><pre class="screen">[2002-Jan-01 01:25:10.000000001/ \
2002-Jan-31 01:25:10.123456789]</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">operator>></pre></td>
<td>Input streaming operator for time duration. Uses facet to read [date time_of_day/date time_of_day]. The default is format is <code class="computeroutput">[YYYY-mmm-DD hh:mm:ss.fffffffff/YYYY-mmm-DD hh:mm:ss.fffffffff]</code> string where <code class="computeroutput">mmm</code> is 3 char month name and the fractional seconds are left out when zero.</td>
</tr>
<tr><td><pre class="screen">[2002-Jan-01 01:25:10.000000001/ \
2002-Jan-31 01:25:10.123456789]</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">operator==, operator!=</pre></td>
<td>Equality operators. Periods are equal if p1.begin == p2.begin && p1.last == p2.last</td>
</tr>
<tr><td><pre class="screen">if (tp1 == tp2) {...</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">operator<</pre></td>
<td>Ordering with no overlap. True if tp1.end() less than tp2.begin()</td>
</tr>
<tr><td><pre class="screen">if (tp1 < tp2) {...</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">operator></pre></td>
<td>Ordering with no overlap. True if tp1.begin() greater than tp2.end()</td>
</tr>
<tr><td><pre class="screen">if (tp1 > tp2) {... etc</pre></td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">operator<=, operator>=</pre></td>
<td>Defined in terms of the other operators.</td>
</tr>
<tr><td> </td></tr>
</tbody>
</table></div>
<p>
</p>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="date_time.posix_time.time_iterators"></a>Time Iterators</h3></div></div></div>
<a class="link" href="posix_time.html#time_iter_intro">Introduction</a> --
<a class="link" href="posix_time.html#time_iter_header">Header</a> --
<a class="link" href="posix_time.html#time_iter_overview">Overview</a> --
<a class="link" href="posix_time.html#time_iter_operators">Operators</a><a name="time_iter_intro"></a><h4>
<a name="idp206505632"></a>Introduction</h4>
<p>
Time iterators provide a mechanism for iteration through times. Time iterators are similar to <a href="http://www.sgi.com/tech/stl/BidirectionalIterator.html" target="_top">Bidirectional Iterators</a>. However, time_iterators are different than standard iterators in that there is no underlying sequence, just a calculation function. In addition, time_iterators are directly comparable against instances of <a class="link" href="posix_time.html#date_time.posix_time.ptime_class" title="Ptime">class ptime</a>. Thus a second iterator for the end point of the iteration is not required, but rather a point in time can be used directly. For example, the following code iterates using a 15 minute iteration interval. The <a class="link" href="examples.html#date_time.examples.print_hours" title="Print Hours">print hours</a> example also illustrates the use of the time_iterator.
</p>
<p>
</p>
<pre class="programlisting">
#include "boost/date_time/posix_time/posix_time.hpp"
#include <iostream>
int
main()
{
using namespace boost::gregorian;
using namespace boost::posix_time;
date d(2000,Jan,20);
ptime start(d);
ptime end = start + hours(1);
time_iterator titr(start,minutes(15)); //increment by 15 minutes
//produces 00:00:00, 00:15:00, 00:30:00, 00:45:00
while (titr < end) {
std::cout << to_simple_string(*titr) << std::endl;
++titr;
}
std::cout << "Now backward" << std::endl;
//produces 01:00:00, 00:45:00, 00:30:00, 00:15:00
while (titr > start) {
std::cout << to_simple_string(*titr) << std::endl;
--titr;
}
}
</pre>
<p>
</p>
<a name="time_iter_header"></a><h4>
<a name="idp206512560"></a>Header</h4>
<p>
</p>
<pre class="programlisting">#include "boost/date_time/posix_time/posix_time.hpp" //include all types plus i/o
or
#include "boost/date_time/posix_time/posix_time_types.hpp" //no i/o just types</pre>
<p>
</p>
<a name="time_iter_overview"></a><h4>
<a name="idp206515152"></a>Overview</h4>
<p>
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Class</th>
<th>Description</th>
</tr>
<tr><th>Construction Parameters</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top"><pre class="screen">time_iterator</pre></td>
<td>Iterate incrementing by the specified duration.</td>
</tr>
<tr><td><pre class="screen">ptime start_time, time_duration increment</pre></td></tr>
</tbody>
</table></div>
<p>
</p>
<a name="time_iter_operators"></a><h4>
<a name="idp206524784"></a>Operators</h4>
<p>
</p>
<div class="informaltable"><table class="table">
<colgroup>
<col>
<col>
</colgroup>
<thead>
<tr>
<th rowspan="2" valign="top">Syntax</th>
<th>Description</th>
</tr>
<tr><th>Example</th></tr>
</thead>
<tbody>
<tr>
<td rowspan="2" valign="top">
<pre class="screen">operator==(const ptime& rhs),
operator!=(const ptime& rhs),
operator>, operator<,
operator>=, operator<=</pre>
</td>
<td>A full complement of comparison operators</td>
</tr>
<tr><td>
<pre class="screen">date d(2002,Jan,1);
ptime start_time(d, hours(1));
//increment by 10 minutes
time_iterator titr(start_time, minutes(10));
ptime end_time = start_time + hours(2);
if (titr == end_time) // false
if (titr != end_time) // true
if (titr >= end_time) // false
if (titr <= end_time) // true</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">prefix increment</pre></td>
<td>Increment the iterator by the specified duration.</td>
</tr>
<tr><td>
<pre class="screen">//increment by 10 milli seconds
time_iterator titr(start_time, milliseconds(10));
++titr; // == start_time + 10 milliseconds</pre>
</td></tr>
<tr>
<td rowspan="2" valign="top"><pre class="screen">prefix decrement</pre></td>
<td>Decrement the iterator by the specified time duration.</td>
</tr>
<tr><td><pre class="screen">time_duration td(1,2,3);
time_iterator titr(start_time, td);
--titr; // == start_time - 01:02:03</pre></td></tr>
</tbody>
</table></div>
<p>
</p>
</div>
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"></td>
<td align="right"><div class="copyright-footer">Copyright © 2001-2005 CrystalClear Software, Inc<p>Subject to the Boost Software License, Version 1.0. (See accompanying file
<code class="filename">LICENSE_1_0.txt</code> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)</p>
</div></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="gregorian.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../date_time.html"><img src="../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="local_time.html"><img src="../../../doc/src/images/next.png" alt="Next"></a>
</div>
</body>
</html>
|
