summaryrefslogtreecommitdiffstats
path: root/src/qt3support/tools/q3cstring.cpp
blob: b33b9b6c77952ed7b499c86cc25d69182117a88e (plain)
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
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the Qt3Support module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the either Technology Preview License Agreement or the
** Beta Release License Agreement.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain
** additional rights. These rights are described in the Nokia Qt LGPL
** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at http://www.qtsoftware.com/contact.
** $QT_END_LICENSE$
**
****************************************************************************/

#include "q3cstring.h"
#include "qregexp.h"
#include "qdatastream.h"

#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <ctype.h>
#include <limits.h>

QT_BEGIN_NAMESPACE

/*****************************************************************************
  Q3CString member functions
 *****************************************************************************/

/*!
    \class Q3CString
    \reentrant
    \brief The Q3CString class provides an abstraction of the classic C
    zero-terminated char array (char *).

    \compat

    Q3CString tries to behave like a more convenient \c{const char *}.
    The price of doing this is that some algorithms will perform
    badly. For example, append() is O(length()) since it scans for a
    null terminator. Although you might use Q3CString for text that is
    never exposed to the user, for most purposes, and especially for
    user-visible text, you should use QString. QString provides
    implicit sharing, Unicode and other internationalization support,
    and is well optimized.

    Note that for the Q3CString methods that take a \c{const char *}
    parameter the \c{const char *} must either be 0 (null) or not-null
    and '\0' (NUL byte) terminated; otherwise the results are
    undefined.

    A default constructed Q3CString is \e null, i.e. both the length
    and the data pointer are 0 and isNull() returns true.
    
    \note However, if you ask for the data pointer of a null Q3CString
    by calling data(), then because the internal representation of the
    null Q3CString is shared, it will be detached and replaced with a
    non-shared, empty representation, a non-null data pointer will be
    returned, and subsequent calls to isNull() will return false. But
    if you ask for the data pointer of a null Q3CString by calling
    constData(), the shared internal representation is not detached, a
    null data pointer is returned, and subsequent calls to isNull()
    will continue to return true.

    A Q3CString that references the empty string ("", a single '\0'
    char) is \e empty, i.e. isEmpty() returns true.  Both null and
    empty Q3CStrings are legal parameters to the methods.  Assigning
    \c{const char *} 0 to Q3CString produces a null Q3CString.

    The length() function returns the length of the string; resize()
    resizes the string and truncate() truncates the string. A string
    can be filled with a character using fill(). Strings can be left
    or right padded with characters using leftJustify() and
    rightJustify(). Characters, strings and regular expressions can be
    searched for using find() and findRev(), and counted using
    contains().

    Strings and characters can be inserted with insert() and appended
    with append(). A string can be prepended with prepend().
    Characters can be removed from the string with remove() and
    replaced with replace().

    Portions of a string can be extracted using left(), right() and
    mid(). Whitespace can be removed using stripWhiteSpace() and
    simplifyWhiteSpace(). Strings can be converted to uppercase or
    lowercase with upper() and lower() respectively.

    Strings that contain numbers can be converted to numbers with
    toShort(), toInt(), toLong(), toULong(), toFloat() and toDouble().
    Numbers can be converted to strings with setNum().

    Many operators are overloaded to work with Q3CStrings. Q3CString
    also supports some more obscure functions, e.g. sprintf(),
    setStr() and setExpand().

    \sidebar Note on Character Comparisons

    In Q3CString the notion of uppercase and lowercase and of which
    character is greater than or less than another character is locale
    dependent. This affects functions which support a case insensitive
    option or which compare or lowercase or uppercase their arguments.
    Case insensitive operations and comparisons will be accurate if
    both strings contain only ASCII characters. (If \c $LC_CTYPE is
    set, most Unix systems do "the right thing".) Functions that this
    affects include contains(), find(), findRev(), \l operator<(), \l
    operator<=(), \l operator>(), \l operator>=(), lower() and
    upper().

    This issue does not apply to \l{QString}s since they represent
    characters using Unicode.
    \endsidebar

    Performance note: The Q3CString methods for QRegExp searching are
    implemented by converting the Q3CString to a QString and performing
    the search on that. This implies a deep copy of the Q3CString data.
    If you are going to perform many QRegExp searches on a large
    Q3CString, you will get better performance by converting the
    Q3CString to a QString yourself, and then searching in the QString.
*/

/*!
    \fn Q3CString Q3CString::left(uint len)  const

    \internal
*/

/*!
    \fn Q3CString Q3CString::right(uint len) const

    \internal
*/

/*!
    \fn Q3CString Q3CString::mid(uint index, uint len) const

    \internal
*/

/*!
    \fn Q3CString  Q3CString::lower() const

    Use QByteArray::toLower() instead.
*/

/*!
    \fn Q3CString  Q3CString::upper() const

    Use QByteArray::toUpper() instead.
*/

/*!
    \fn Q3CString  Q3CString::stripWhiteSpace() const

    Use QByteArray::trimmed() instead.
*/

/*!
    \fn Q3CString  Q3CString::simplifyWhiteSpace() const

    Use QByteArray::simplified() instead.
*/

/*!
    \fn Q3CString& Q3CString::insert(uint index, const char *c)

    \internal
*/

/*!
    \fn Q3CString& Q3CString::insert(uint index, char c)

    \internal
*/

/*!
    \fn Q3CString& Q3CString::prepend(const char *c)

    \internal
*/

/*!
    \fn Q3CString& Q3CString::remove(uint index, uint len)

    \internal
*/

/*!
    \fn Q3CString& Q3CString::replace(uint index, uint len, const char *c)

    \internal
*/

/*!
    \fn Q3CString& Q3CString::replace(char c, const Q3CString &after)

    \internal
*/

/*!
    \fn Q3CString& Q3CString::replace(char c, const char *after)

    \internal
*/

/*!
    \fn Q3CString& Q3CString::replace(const Q3CString &b, const Q3CString &a)

    \internal
*/

/*!
    \fn Q3CString& Q3CString::replace(const char *b, const char *a)

    \internal
*/

/*!
    \fn Q3CString& Q3CString::replace(char b, char a)

    \internal
*/

/*!
    \fn Q3CString::Q3CString()

    Constructs a null string.

    \sa isNull()
*/

/*!
    \fn Q3CString::Q3CString(const QByteArray &ba)

    Constructs a copy of \a ba.
*/

/*!
    \fn Q3CString::Q3CString(const Q3CString &s)

    Constructs a shallow copy \a s.
*/

/*! \fn Q3CString::Q3CString(int size)
    Constructs a string with room for \a size characters, including
    the '\0'-terminator. Makes a null string if \a size == 0.

    If \a size \> 0, then the first and last characters in the string
    are initialized to '\0'. All other characters are uninitialized.

    \sa resize(), isNull()
*/

/*! \fn Q3CString::Q3CString(const char *str)
    Constructs a string that is a deep copy of \a str.

    If \a str is 0 a null string is created.

    \sa isNull()
*/


/*! \fn Q3CString::Q3CString(const char *str, uint maxsize)

    Constructs a string that is a deep copy of \a str. The copy will
    be at most \a maxsize bytes long including the '\0'-terminator.

    Example:
    \snippet doc/src/snippets/code/src_qt3support_tools_q3cstring.cpp 0

    If \a str contains a 0 byte within the first \a maxsize bytes, the
    resulting Q3CString will be terminated by this 0. If \a str is 0 a
    null string is created.

    \sa isNull()
*/

/*!
    \fn Q3CString &Q3CString::operator=(const QByteArray &ba)

    Assigns byte array \a ba to this Q3CString.
*/

/*!
    \fn Q3CString &Q3CString::operator=(const Q3CString &s)

    Assigns a shallow copy of \a s to this string and returns a
    reference to this string.
*/

/*!
    \fn Q3CString &Q3CString::operator=(const char *str)
    \overload

    Assigns a deep copy of \a str to this string and returns a
    reference to this string.

    If \a str is 0 a null string is created.

    \sa isNull()
*/

/*
    \fn bool Q3CString::isNull() const

    Returns true if the string is null, i.e. if data() == 0; otherwise
    returns false. A null string is also an empty string.

    \note If you ask for the data pointer of a null Q3CString by
    calling data(), then because the internal representation of the
    null Q3CString is shared, it will be detached and replaced with a
    non-shared, empty representation, a non-null data pointer will be
    returned, and subsequent calls to isNull() will return false. But
    if you ask for the data pointer of a null Q3CString by calling
    constData(), the shared internal representation is not detached, a
    null data pointer is returned, and subsequent calls to isNull()
    will continue to return true.

    Example:
    \snippet doc/src/snippets/code/src.qt3support.tools.q3cstring.cpp 1

    \sa isEmpty(), length(), size()
*/

/*
    \fn bool Q3CString::isEmpty() const

    Returns true if the string is empty, i.e. if length() == 0;
    otherwise returns false. An empty string is not always a null
    string.

    See example in isNull().

    \sa isNull(), length(), size()
*/

/*
    \fn uint Q3CString::length() const

    Returns the length of the string, excluding the '\0'-terminator.
    Equivalent to calling \c strlen(data()).

    Null strings and empty strings have zero length.

    \sa size(), isNull(), isEmpty()
*/

/*
    \fn bool Q3CString::truncate(uint pos)

    Truncates the string at position \a pos.

    Equivalent to calling \c resize(pos+1).

    Example:
    \snippet doc/src/snippets/code/src.qt3support.tools.q3cstring.cpp 2

    \sa resize()
*/



/*!
    Implemented as a call to the native vsprintf() (see the manual for
    your C library).

    If the string is shorter than 256 characters, this sprintf() calls
    resize(256) to decrease the chance of memory corruption. The
    string is resized back to its actual length before sprintf()
    returns.

    Example:
    \snippet doc/src/snippets/code/src_qt3support_tools_q3cstring.cpp 3

    \warning All vsprintf() implementations will write past the end of
    the target string (*this) if the \a format specification and
    arguments happen to be longer than the target string, and some
    will also fail if the target string is longer than some arbitrary
    implementation limit.

    Giving user-supplied arguments to sprintf() is risky: Sooner or
    later someone will paste a huge line into your application.
*/

Q3CString &Q3CString::sprintf(const char *format, ...)
{
    detach();
    va_list ap;
    va_start(ap, format);
    if (size() < 256)
        resize(256);                // make string big enough
    qvsnprintf(data(), size(), format, ap);
    resize(qstrlen(constData()));
    va_end(ap);
    return *this;
}



/*!
    \fn Q3CString Q3CString::copy() const

    Returns a deep copy of this string.
*/


/*!
    Returns a string of length \a width (plus one for the terminating
    '\0') that contains this string padded with the \a fill character.

    If the length of the string exceeds \a width and \a truncate is
    false (the default), then the returned string is a copy of the
    string. If the length of the string exceeds \a width and \a
    truncate is true, then the returned string is a left(\a width).

    Example:
    \snippet doc/src/snippets/code/src_qt3support_tools_q3cstring.cpp 4

    \sa rightJustify()
*/

Q3CString Q3CString::leftJustify(uint width, char fill, bool truncate) const
{
    Q3CString result;
    int len = qstrlen(constData());
    int padlen = width - len;
    if (padlen > 0) {
        result.resize(len+padlen);
        memcpy(result.data(), constData(), len);
        memset(result.data()+len, fill, padlen);
    } else {
        if (truncate)
            result = left(width);
        else
            result = *this;
    }
    return result;
}

/*!
    Returns a string of length \a width (plus one for the terminating
    '\0') that contains zero or more of the \a fill character followed
    by this string.

    If the length of the string exceeds \a width and \a truncate is
    false (the default), then the returned string is a copy of the
    string. If the length of the string exceeds \a width and \a
    truncate is true, then the returned string is a left(\a width).

    Example:
    \snippet doc/src/snippets/code/src_qt3support_tools_q3cstring.cpp 5

    \sa leftJustify()
*/

Q3CString Q3CString::rightJustify(uint width, char fill, bool truncate) const
{
    Q3CString result;
    int len = qstrlen(constData());
    int padlen = width - len;
    if (padlen > 0) {
        result.resize(len+padlen);
        memset(result.data(), fill, padlen);
        memcpy(result.data()+padlen, constData(), len);
    } else {
        if (truncate)
            result = left(width);
        else
            result = *this;
    }
    return result;
}

/*!
    Returns the string converted to a \c long value.

    If \a ok is not 0: *\a ok is set to false if the string is not a
    number, or if it has trailing garbage; otherwise *\a ok is set to
    true.
*/

long Q3CString::toLong(bool *ok) const
{
    const char *p = constData();
    long val=0;
    const long max_mult = 214748364;
    bool is_ok = false;
    int neg = 0;
    if (!p)
        goto bye;
    while (isspace((uchar) *p))                // skip leading space
        p++;
    if (*p == '-') {
        p++;
        neg = 1;
    } else if (*p == '+') {
        p++;
    }
    if (!isdigit((uchar) *p))
        goto bye;
    while (isdigit((uchar) *p)) {
        if (val > max_mult || (val == max_mult && (*p-'0') > 7+neg))
            goto bye;
        val = 10*val + (*p++ - '0');
    }
    if (neg)
        val = -val;
    while (isspace((uchar) *p))                // skip trailing space
        p++;
    if (*p == '\0')
        is_ok = true;
bye:
    if (ok)
        *ok = is_ok;
    return is_ok ? val : 0;
}

/*!
    Returns the string converted to an \c{unsigned long} value.

    If \a ok is not 0: *\a ok is set to false if the string is not a
    number, or if it has trailing garbage; otherwise *\a ok is set to
    true.
*/

ulong Q3CString::toULong(bool *ok) const
{
    const char *p = constData();
    ulong val=0;
    const ulong max_mult = 429496729;
    bool is_ok = false;
    if (!p)
        goto bye;
    while (isspace((uchar) *p))                // skip leading space
        p++;
    if (*p == '+')
        p++;
    if (!isdigit((uchar) *p))
        goto bye;
    while (isdigit((uchar) *p)) {
        if (val > max_mult || (val == max_mult && (*p-'0') > 5))
            goto bye;
        val = 10*val + (*p++ - '0');
    }
    while (isspace((uchar) *p))                // skip trailing space
        p++;
    if (*p == '\0')
        is_ok = true;
bye:
    if (ok)
        *ok = is_ok;
    return is_ok ? val : 0;
}

/*!
    Returns the string converted to a \c{short} value.

    If \a ok is not 0: *\a ok is set to false if the string is not a
    number, is out of range, or if it has trailing garbage; otherwise
    *\a ok is set to true.
*/

short Q3CString::toShort(bool *ok) const
{
    long v = toLong(ok);
    if (ok && *ok && (v < -32768 || v > 32767))
        *ok = false;
    return (short)v;
}

/*!
    Returns the string converted to an \c{unsigned short} value.

    If \a ok is not 0: *\a ok is set to false if the string is not a
    number, is out of range, or if it has trailing garbage; otherwise
    *\a ok is set to true.
*/

ushort Q3CString::toUShort(bool *ok) const
{
    ulong v = toULong(ok);
    if (ok && *ok && (v > 65535))
        *ok = false;
    return (ushort)v;
}


/*!
    Returns the string converted to a \c{int} value.

    If \a ok is not 0: *\a ok is set to false if the string is not a
    number, or if it has trailing garbage; otherwise *\a ok is set to
    true.
*/

int Q3CString::toInt(bool *ok) const
{
    return (int)toLong(ok);
}

/*!
    Returns the string converted to an \c{unsigned int} value.

    If \a ok is not 0: *\a ok is set to false if the string is not a
    number, or if it has trailing garbage; otherwise *\a ok is set to
    true.
*/

uint Q3CString::toUInt(bool *ok) const
{
    return (uint)toULong(ok);
}

/*!
    Returns the string converted to a \c{double} value.

    If \a ok is not 0: *\a ok is set to false if the string is not a
    number, or if it has trailing garbage; otherwise *\a ok is set to
    true.
*/

double Q3CString::toDouble(bool *ok) const
{
    char *end;
    double val = strtod(constData() ? constData() : "", &end);
    if (ok)
        *ok = (constData() && *constData() && (end == 0 || *end == '\0'));
    return val;
}

/*!
    Returns the string converted to a \c{float} value.

    If \a ok is not 0: *\a ok is set to false if the string is not a
    number, or if it has trailing garbage; otherwise *\a ok is set to
    true.
*/

float Q3CString::toFloat(bool *ok) const
{
    return (float)toDouble(ok);
}


/*! \fn Q3CString &Q3CString::setStr(const char *str)
    Makes a deep copy of \a str. Returns a reference to the string.
*/

/*!
    \overload

    Sets the string to the string representation of the number \a n
    and returns a reference to the string.
*/

Q3CString &Q3CString::setNum(long n)
{
    data();
    char buf[20];
    register char *p = &buf[19];
    bool neg;
    if (n < 0) {
        neg = true;
        n = -n;
    } else {
        neg = false;
    }
    *p = '\0';
    do {
        *--p = ((int)(n%10)) + '0';
        n /= 10;
    } while (n);
    if (neg)
        *--p = '-';
    *this = p;
    return *this;
}

/*!
    \overload

    Sets the string to the string representation of the number \a n
    and returns a reference to the string.
*/

Q3CString &Q3CString::setNum(ulong n)
{
    data();
    char buf[20];
    register char *p = &buf[19];
    *p = '\0';
    do {
        *--p = ((int)(n%10)) + '0';
        n /= 10;
    } while (n);
    *this = p;
    return *this;
}

/*!
    \fn Q3CString &Q3CString::setNum(int n)
    \overload

    Sets the string to the string representation of the number \a n
    and returns a reference to the string.
*/

/*!
    \fn Q3CString &Q3CString::setNum(uint n)
    \overload

    Sets the string to the string representation of the number \a n
    and returns a reference to the string.
*/

/*!
    \fn Q3CString &Q3CString::setNum(short n)
    \overload

    Sets the string to the string representation of the number \a n
    and returns a reference to the string.
*/

/*!
    \fn Q3CString &Q3CString::setNum(ushort n)
    \overload

    Sets the string to the string representation of the number \a n
    and returns a reference to the string.
*/

/*!
    Sets the string to the string representation of the number \a n
    and returns a reference to the string.

    The format of the string representation is specified by the format
    character \a f, and the precision (number of digits after the
    decimal point) is specified with \a prec.

    The valid formats for \a f are 'e', 'E', 'f', 'g' and 'G'. The
    formats are the same as for sprintf(); they are explained in \l
    QString::arg().
*/

Q3CString &Q3CString::setNum(double n, char f, int prec)
{
#ifndef QT_NO_DEBUG
    if (!(f=='f' || f=='F' || f=='e' || f=='E' || f=='g' || f=='G'))
        qWarning("Q3CString::setNum: Invalid format char '%c'", f);
#endif
    char format[20];
    register char *fs = format;                        // generate format string
    *fs++ = '%';                                //   "%.<prec>l<f>"
    if (prec > 99)
        prec = 99;
    *fs++ = '.';
    if (prec >= 10) {
        *fs++ = prec / 10 + '0';
        *fs++ = prec % 10 + '0';
    } else {
        *fs++ = prec + '0';
    }
    *fs++ = 'l';
    *fs++ = f;
    *fs = '\0';
    return sprintf(format, n);
}

/*! \fn Q3CString &Q3CString::setNum(float n, char f, int prec)
    \overload
*/

/*!
    Sets the character at position \a index to \a c and expands the
    string if necessary, padding with spaces.

    Returns false if \a index was out of range and the string could
    not be expanded; otherwise returns true.
*/

bool Q3CString::setExpand(uint index, char c)
{
    uint oldlen = length();
    if (index >= oldlen) {
        resize(index+1);
        if (index > oldlen)
            memset(data() + oldlen, ' ', index - oldlen);
    }
    *(data() + index) = c;
    return true;
}


/*
    \fn Q3CString::operator const char *() const

    Returns the string data.
*/


/*!
    \fn Q3CString& Q3CString::append(const char *str)

    Appends string \a str to the string and returns a reference to the
    string. Equivalent to operator+=().
*/



#ifndef QT_NO_DATASTREAM
/*! \fn QDataStream &operator<<(QDataStream &s, const Q3CString &str)
    \relates Q3CString

    Writes string \a str to the stream \a s.

    \sa \link datastreamformat.html Format of the QDataStream operators \endlink
*/
QDataStream &operator<<(QDataStream &d, const Q3CString &s)
{
    if (d.version() >= QDataStream::Qt_4_0)
        return operator<<(d, static_cast<const QByteArray &>(s));

    // we need to add a NUL to keep compatibility with Qt 3's QByteArray
    QByteArray copy = s;
    copy.append('\0');
    return operator<<(d, copy);
}

/*!
  \fn QDataStream &operator>>(QDataStream &s, Q3CString &str)
    \relates Q3CString

    Reads a string into \a str from the stream \a s.

    \sa \link datastreamformat.html Format of the QDataStream operators \endlink
*/
QDataStream &operator>>(QDataStream &d, Q3CString &s) {
    operator>>(d, static_cast<QByteArray &>(s));
    if (d.version() < QDataStream::Qt_4_0 && s.endsWith('\0'))
        s.chop(1);                  // ending NUL
    return d;
}
#endif

/*****************************************************************************
  Documentation for related functions
 *****************************************************************************/

/*!
    \fn bool operator==(const Q3CString &s1, const Q3CString &s2)

    \relates Q3CString

    Returns true if \a s1 and \a s2 are equal; otherwise returns false.

    Equivalent to qstrcmp(\a s1, \a s2) == 0.
*/

/*!
    \fn bool operator==(const Q3CString &s1, const char *s2)
    \overload

    \relates Q3CString

    Returns true if \a s1 and \a s2 are equal; otherwise returns false.

    Equivalent to qstrcmp(\a s1, \a s2) == 0.
*/

/*!
    \fn bool operator==(const char *s1, const Q3CString &s2)
    \overload

    \relates Q3CString

    Returns true if \a s1 and \a s2 are equal; otherwise returns false.

    Equivalent to qstrcmp(\a s1, \a s2) == 0.
*/

/*!
    \fn bool operator!=(const Q3CString &s1, const Q3CString &s2)

    \relates Q3CString

    Returns true if \a s1 and \a s2 are different; otherwise returns false.

    Equivalent to qstrcmp(\a s1, \a s2) != 0.
*/

/*!
    \fn bool operator!=(const Q3CString &s1, const char *s2)
    \overload

    \relates Q3CString

    Returns true if \a s1 and \a s2 are different; otherwise returns false.

    Equivalent to qstrcmp(\a s1, \a s2) != 0.
*/

/*!
    \fn bool operator!=(const char *s1, const Q3CString &s2)
    \overload

    \relates Q3CString

    Returns true if \a s1 and \a s2 are different; otherwise returns false.

    Equivalent to qstrcmp(\a s1, \a s2) != 0.
*/

/*!
    \fn bool operator<(const Q3CString &s1, const char *s2)

    \relates Q3CString

    Returns true if \a s1 is less than \a s2; otherwise returns false.

    Equivalent to qstrcmp(\a s1, \a s2) \< 0.
*/

/*!
    \fn bool operator<(const char *s1, const Q3CString &s2)
    \overload

    \relates Q3CString

    Returns true if \a s1 is less than \a s2; otherwise returns false.

    Equivalent to qstrcmp(\a s1, \a s2) \< 0.
*/

/*!
    \fn bool operator<=(const Q3CString &s1, const char *s2)

    \relates Q3CString

    Returns true if \a s1 is less than or equal to \a s2; otherwise
    returns false.

    Equivalent to qstrcmp(\a s1, \a s2) \<= 0.
*/

/*!
    \fn bool operator<=(const char *s1, const Q3CString &s2)
    \overload

    \relates Q3CString

    Returns true if \a s1 is less than or equal to \a s2; otherwise
    returns false.

    Equivalent to qstrcmp(\a s1, \a s2) \<= 0.
*/

/*!
    \fn bool operator>(const Q3CString &s1, const char *s2)

    \relates Q3CString

    Returns true if \a s1 is greater than \a s2; otherwise returns false.

    Equivalent to qstrcmp(\a s1, \a s2) \> 0.
*/

/*!
    \fn bool operator>(const char *s1, const Q3CString &s2)
    \overload

    \relates Q3CString

    Returns true if \a s1 is greater than \a s2; otherwise returns false.

    Equivalent to qstrcmp(\a s1, \a s2) \> 0.
*/

/*!
    \fn bool operator>=(const Q3CString &s1, const char *s2)

    \relates Q3CString

    Returns true if \a s1 is greater than or equal to \a s2; otherwise
    returns false.

    Equivalent to qstrcmp(\a s1, \a s2) \>= 0.
*/

/*!
    \fn bool operator>=(const char *s1, const Q3CString &s2)
    \overload

    \relates Q3CString

    Returns true if \a s1 is greater than or equal to \a s2; otherwise
    returns false.

    Equivalent to qstrcmp(\a s1, \a s2) \>= 0.
*/

/*!
    \fn const Q3CString operator+(const Q3CString &s1, const Q3CString &s2)

    \relates Q3CString

    Returns a string which consists of the concatenation of \a s1 and
    \a s2.
*/

/*!
    \fn const Q3CString operator+(const Q3CString &s1, const char *s2)
    \overload

    \relates Q3CString

    Returns a string which consists of the concatenation of \a s1 and \a s2.
*/

/*!
    \fn const Q3CString operator+(const char *s1, const Q3CString &s2)
    \overload

    \relates Q3CString

    Returns a string which consists of the concatenation of \a s1 and \a s2.
*/

/*!
    \fn const Q3CString operator+(const Q3CString &s, char c)
    \overload

    \relates Q3CString

    Returns a string which consists of the concatenation of \a s and \a c.
*/

/*!
    \fn const Q3CString operator+(char c, const Q3CString &s)
    \overload

    \relates Q3CString
    Returns a string which consists of the concatenation of \a c and \a s.
*/

QT_END_NAMESPACE