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author | Alexandru Croitor <alexandru.croitor@qt.io> | 2019-08-15 13:09:55 +0200 |
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committer | Alexandru Croitor <alexandru.croitor@qt.io> | 2019-08-15 16:53:19 +0200 |
commit | c7ec7cd2a1ae9bec31113fae1f1e549b2bf98e0b (patch) | |
tree | fc81fba4e7815ea061da277cf3bcf3102866932f /src/corelib/text/qstringbuilder.cpp | |
parent | 7947032e2d1d68b2c0f79874db7adcf560851f29 (diff) | |
parent | 6132260da394a9627947f0fe6a279c20863b6ad2 (diff) |
Merge branch 'wip/qt6' into wip/cmake
Change-Id: I50ac36b8803c296998149e98cc61e38687cdd14b
Diffstat (limited to 'src/corelib/text/qstringbuilder.cpp')
-rw-r--r-- | src/corelib/text/qstringbuilder.cpp | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/src/corelib/text/qstringbuilder.cpp b/src/corelib/text/qstringbuilder.cpp new file mode 100644 index 0000000000..cf443ec369 --- /dev/null +++ b/src/corelib/text/qstringbuilder.cpp @@ -0,0 +1,137 @@ +/**************************************************************************** +** +** Copyright (C) 2016 The Qt Company Ltd. +** Contact: https://www.qt.io/licensing/ +** +** This file is part of the QtCore module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** Commercial License Usage +** Licensees holding valid commercial Qt licenses may use this file in +** accordance with the commercial license agreement provided with the +** Software or, alternatively, in accordance with the terms contained in +** a written agreement between you and The Qt Company. For licensing terms +** and conditions see https://www.qt.io/terms-conditions. For further +** information use the contact form at https://www.qt.io/contact-us. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 3 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL3 included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 3 requirements +** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 2.0 or (at your option) the GNU General +** Public license version 3 or any later version approved by the KDE Free +** Qt Foundation. The licenses are as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 +** included in the packaging of this file. Please review the following +** information to ensure the GNU General Public License requirements will +** be met: https://www.gnu.org/licenses/gpl-2.0.html and +** https://www.gnu.org/licenses/gpl-3.0.html. +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qstringbuilder.h" +#include <private/qutfcodec_p.h> + +QT_BEGIN_NAMESPACE + +/*! + \class QStringBuilder + \inmodule QtCore + \internal + \reentrant + \since 4.6 + + \brief The QStringBuilder class is a template class that provides a facility to build up QStrings and QByteArrays from smaller chunks. + + \ingroup tools + \ingroup shared + \ingroup string-processing + + + To build a QString by multiple concatenations, QString::operator+() + is typically used. This causes \e{n - 1} allocations when building + a string from \e{n} chunks. The same is true for QByteArray. + + QStringBuilder uses expression templates to collect the individual + chunks, compute the total size, allocate the required amount of + memory for the final string object, and copy the chunks into the + allocated memory. + + The QStringBuilder class is not to be used explicitly in user + code. Instances of the class are created as return values of the + operator%() function, acting on objects of the following types: + + For building QStrings: + + \list + \li QString, QStringRef, (since 5.10:) QStringView + \li QChar, QCharRef, QLatin1Char, (since 5.10:) \c char16_t, + \li QLatin1String, + \li (since 5.10:) \c{const char16_t[]} (\c{u"foo"}), + \li QByteArray, \c char, \c{const char[]}. + \endlist + + The types in the last list point are only available when + \c QT_NO_CAST_FROM_ASCII is not defined. + + For building QByteArrays: + + \list + \li QByteArray, \c char, \c{const char[]}. + \endlist + + Concatenating strings with operator%() generally yields better + performance than using \c QString::operator+() on the same chunks + if there are three or more of them, and performs equally well in other + cases. + + \sa QLatin1String, QString +*/ + +/*! \fn template <typename A, typename B> QStringBuilder<A, B>::QStringBuilder(const A &a, const B &b) + Constructs a QStringBuilder from \a a and \a b. + */ + +/* \fn template <typename A, typename B> QStringBuilder<A, B>::operator%(const A &a, const B &b) + + Returns a \c QStringBuilder object that is converted to a QString object + when assigned to a variable of QString type or passed to a function that + takes a QString parameter. + + This function is usable with arguments of type \c QString, + \c QLatin1String, \c QStringRef, + \c QChar, \c QCharRef, \c QLatin1Char, and \c char. +*/ + +/* \fn template <typename A, typename B> QByteArray QStringBuilder<A, B>::toLatin1() const + Returns a Latin-1 representation of the string as a QByteArray. The + returned byte array is undefined if the string contains non-Latin1 + characters. + */ +/* \fn template <typename A, typename B> QByteArray QStringBuilder<A, B>::toUtf8() const + Returns a UTF-8 representation of the string as a QByteArray. + */ + + +/*! + \internal + */ +void QAbstractConcatenable::convertFromAscii(const char *a, int len, QChar *&out) noexcept +{ + if (Q_UNLIKELY(len == -1)) { + if (!a) + return; + len = int(strlen(a)); + } + out = QUtf8::convertToUnicode(out, a, len); +} + +QT_END_NAMESPACE |