1 | /**************************************************************************** |
2 | ** |
3 | ** Copyright (C) 2016 The Qt Company Ltd. |
4 | ** Contact: https://www.qt.io/licensing/ |
5 | ** |
6 | ** This file is part of the QtCore module of the Qt Toolkit. |
7 | ** |
8 | ** $QT_BEGIN_LICENSE:LGPL$ |
9 | ** Commercial License Usage |
10 | ** Licensees holding valid commercial Qt licenses may use this file in |
11 | ** accordance with the commercial license agreement provided with the |
12 | ** Software or, alternatively, in accordance with the terms contained in |
13 | ** a written agreement between you and The Qt Company. For licensing terms |
14 | ** and conditions see https://www.qt.io/terms-conditions. For further |
15 | ** information use the contact form at https://www.qt.io/contact-us. |
16 | ** |
17 | ** GNU Lesser General Public License Usage |
18 | ** Alternatively, this file may be used under the terms of the GNU Lesser |
19 | ** General Public License version 3 as published by the Free Software |
20 | ** Foundation and appearing in the file LICENSE.LGPL3 included in the |
21 | ** packaging of this file. Please review the following information to |
22 | ** ensure the GNU Lesser General Public License version 3 requirements |
23 | ** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. |
24 | ** |
25 | ** GNU General Public License Usage |
26 | ** Alternatively, this file may be used under the terms of the GNU |
27 | ** General Public License version 2.0 or (at your option) the GNU General |
28 | ** Public license version 3 or any later version approved by the KDE Free |
29 | ** Qt Foundation. The licenses are as published by the Free Software |
30 | ** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 |
31 | ** included in the packaging of this file. Please review the following |
32 | ** information to ensure the GNU General Public License requirements will |
33 | ** be met: https://www.gnu.org/licenses/gpl-2.0.html and |
34 | ** https://www.gnu.org/licenses/gpl-3.0.html. |
35 | ** |
36 | ** $QT_END_LICENSE$ |
37 | ** |
38 | ****************************************************************************/ |
39 | |
40 | #include "qstringbuilder.h" |
41 | #include <private/qstringconverter_p.h> |
42 | |
43 | QT_BEGIN_NAMESPACE |
44 | |
45 | /*! |
46 | \class QStringBuilder |
47 | \inmodule QtCore |
48 | \internal |
49 | \reentrant |
50 | \since 4.6 |
51 | |
52 | \brief The QStringBuilder class is a template class that provides a facility to build up QStrings and QByteArrays from smaller chunks. |
53 | |
54 | \ingroup tools |
55 | \ingroup shared |
56 | \ingroup string-processing |
57 | |
58 | |
59 | To build a QString by multiple concatenations, QString::operator+() |
60 | is typically used. This causes \e{n - 1} allocations when building |
61 | a string from \e{n} chunks. The same is true for QByteArray. |
62 | |
63 | QStringBuilder uses expression templates to collect the individual |
64 | chunks, compute the total size, allocate the required amount of |
65 | memory for the final string object, and copy the chunks into the |
66 | allocated memory. |
67 | |
68 | The QStringBuilder class is not to be used explicitly in user |
69 | code. Instances of the class are created as return values of the |
70 | operator%() function, acting on objects of the following types: |
71 | |
72 | For building QStrings: |
73 | |
74 | \list |
75 | \li QString, (since 5.10:) QStringView |
76 | \li QChar, QLatin1Char, (since 5.10:) \c char16_t, |
77 | \li QLatin1String, |
78 | \li (since 5.10:) \c{const char16_t[]} (\c{u"foo"}), |
79 | \li QByteArray, \c char, \c{const char[]}. |
80 | \endlist |
81 | |
82 | The types in the last list point are only available when |
83 | \c QT_NO_CAST_FROM_ASCII is not defined. |
84 | |
85 | For building QByteArrays: |
86 | |
87 | \list |
88 | \li QByteArray, \c char, \c{const char[]}. |
89 | \endlist |
90 | |
91 | Concatenating strings with operator%() generally yields better |
92 | performance than using \c QString::operator+() on the same chunks |
93 | if there are three or more of them, and performs equally well in other |
94 | cases. |
95 | |
96 | \sa QLatin1String, QString |
97 | */ |
98 | |
99 | /*! \fn template <typename A, typename B> QStringBuilder<A, B>::QStringBuilder(const A &a, const B &b) |
100 | Constructs a QStringBuilder from \a a and \a b. |
101 | */ |
102 | |
103 | /* \fn template <typename A, typename B> QStringBuilder<A, B>::operator%(const A &a, const B &b) |
104 | |
105 | Returns a \c QStringBuilder object that is converted to a QString object |
106 | when assigned to a variable of QString type or passed to a function that |
107 | takes a QString parameter. |
108 | |
109 | This function is usable with arguments of type \c QString, |
110 | \c QLatin1String, |
111 | \c QChar, \c QLatin1Char, and \c char. |
112 | */ |
113 | |
114 | /* \fn template <typename A, typename B> QByteArray QStringBuilder<A, B>::toLatin1() const |
115 | Returns a Latin-1 representation of the string as a QByteArray. The |
116 | returned byte array is undefined if the string contains non-Latin1 |
117 | characters. |
118 | */ |
119 | /* \fn template <typename A, typename B> QByteArray QStringBuilder<A, B>::toUtf8() const |
120 | Returns a UTF-8 representation of the string as a QByteArray. |
121 | */ |
122 | |
123 | |
124 | /*! |
125 | \internal |
126 | */ |
127 | void QAbstractConcatenable::convertFromUtf8(QByteArrayView in, QChar *&out) noexcept |
128 | { |
129 | out = QUtf8::convertToUnicode(out, in); |
130 | } |
131 | |
132 | QT_END_NAMESPACE |
133 | |