Port from container.count()/length() to size()

This is semantic patch using ClangTidyTransformator:

  auto QtContainerClass = expr(hasType(namedDecl(hasAnyName(<classes>)))).bind(o)
  makeRule(cxxMemberCallExpr(on(QtContainerClass),
                             callee(cxxMethodDecl(hasAnyName({"count", "length"),
                                                  parameterCountIs(0))))),
           changeTo(cat(access(o, cat("size"), "()"))),
           cat("use 'size()' instead of 'count()/length()'"))

a.k.a qt-port-to-std-compatible-api with config Scope: 'Container'.

<classes> are:

    // sequential:
    "QByteArray",
    "QList",
    "QQueue",
    "QStack",
    "QString",
    "QVarLengthArray",
    "QVector",
    // associative:
    "QHash",
    "QMultiHash",
    "QMap",
    "QMultiMap",
    "QSet",
    // Qt has no QMultiSet

Change-Id: Ibe8837be96e8d30d1846881ecd65180c1bc459af
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

58 files changed, 244 insertions, 244 deletions

diff --git a/src/corelib/animation/qabstractanimation.cpp b/src/corelib/animation/qabstractanimation.cpp
index d57ce4ef5f..46ed60d6d1 100644
--- a/src/corelib/animation/qabstractanimation.cpp
+++ b/src/corelib/animation/qabstractanimation.cpp
@@ -283,7 +283,7 @@ void QUnifiedTimer::updateAnimationTimers()
         QScopedValueRollback<bool> guard(insideTick, true);
         if (profilerCallback)
             profilerCallback(delta);
-        for (currentAnimationIdx = 0; currentAnimationIdx < animationTimers.count(); ++currentAnimationIdx) {
+        for (currentAnimationIdx = 0; currentAnimationIdx < animationTimers.size(); ++currentAnimationIdx) {
             QAbstractAnimationTimer *animation = animationTimers.at(currentAnimationIdx);
             animation->updateAnimationsTime(delta);
         }
@@ -294,7 +294,7 @@ void QUnifiedTimer::updateAnimationTimers()
 int QUnifiedTimer::runningAnimationCount()
 {
     int count = 0;
-    for (int i = 0; i < animationTimers.count(); ++i)
+    for (int i = 0; i < animationTimers.size(); ++i)
         count += animationTimers.at(i)->runningAnimationCount();
     return count;
 }
@@ -309,7 +309,7 @@ void QUnifiedTimer::localRestart()
     if (insideRestart)
         return;
 
-    if (!pausedAnimationTimers.isEmpty() && (animationTimers.count() + animationTimersToStart.count() == pausedAnimationTimers.count())) {
+    if (!pausedAnimationTimers.isEmpty() && (animationTimers.size() + animationTimersToStart.size() == pausedAnimationTimers.size())) {
         driver->stop();
         int closestTimeToFinish = closestPausedAnimationTimerTimeToFinish();
         // use a precise timer if the pause will be short
@@ -327,7 +327,7 @@ void QUnifiedTimer::restart()
 {
     {
         QScopedValueRollback<bool> guard(insideRestart, true);
-        for (int i = 0; i < animationTimers.count(); ++i)
+        for (int i = 0; i < animationTimers.size(); ++i)
             animationTimers.at(i)->restartAnimationTimer();
     }
 
@@ -568,7 +568,7 @@ void QAnimationTimer::updateAnimationsTime(qint64 delta)
     //when the CPU load is high
     if (delta) {
         QScopedValueRollback<bool> guard(insideTick, true);
-        for (currentAnimationIdx = 0; currentAnimationIdx < animations.count(); ++currentAnimationIdx) {
+        for (currentAnimationIdx = 0; currentAnimationIdx < animations.size(); ++currentAnimationIdx) {
             QAbstractAnimation *animation = animations.at(currentAnimationIdx);
             int elapsed = QAbstractAnimationPrivate::get(animation)->totalCurrentTime
                           + (animation->direction() == QAbstractAnimation::Forward ? delta : -delta);
diff --git a/src/corelib/animation/qabstractanimation_p.h b/src/corelib/animation/qabstractanimation_p.h
index 2b08ef7756..5be59543c8 100644
--- a/src/corelib/animation/qabstractanimation_p.h
+++ b/src/corelib/animation/qabstractanimation_p.h
@@ -247,7 +247,7 @@ public:
     void updateAnimationsTime(qint64 delta) override;
 
     //useful for profiling/debugging
-    int runningAnimationCount() override { return animations.count(); }
+    int runningAnimationCount() override { return animations.size(); }
 
 private Q_SLOTS:
     void startAnimations();
diff --git a/src/corelib/animation/qanimationgroup.cpp b/src/corelib/animation/qanimationgroup.cpp
index 5502942302..e8ffd99dcb 100644
--- a/src/corelib/animation/qanimationgroup.cpp
+++ b/src/corelib/animation/qanimationgroup.cpp
@@ -138,7 +138,7 @@ int QAnimationGroup::indexOfAnimation(QAbstractAnimation *animation) const
 void QAnimationGroup::addAnimation(QAbstractAnimation *animation)
 {
     Q_D(QAnimationGroup);
-    insertAnimation(d->animations.count(), animation);
+    insertAnimation(d->animations.size(), animation);
 }
 
 /*!
@@ -261,7 +261,7 @@ void QAnimationGroupPrivate::clear(bool onDestruction)
     const QList<QAbstractAnimation *> animationsCopy = animations; // taking a copy
     animations.clear();
     // Clearing backwards so the indices doesn't change while we remove animations.
-    for (int i = animationsCopy.count() - 1; i >= 0; --i) {
+    for (int i = animationsCopy.size() - 1; i >= 0; --i) {
         QAbstractAnimation *animation = animationsCopy.at(i);
         animation->setParent(nullptr);
         QAbstractAnimationPrivate::get(animation)->group = nullptr;
diff --git a/src/corelib/animation/qsequentialanimationgroup.cpp b/src/corelib/animation/qsequentialanimationgroup.cpp
index 25d6d1de37..8e99d9cee0 100644
--- a/src/corelib/animation/qsequentialanimationgroup.cpp
+++ b/src/corelib/animation/qsequentialanimationgroup.cpp
@@ -172,7 +172,7 @@ void QSequentialAnimationGroupPrivate::rewindForwards(const AnimationIndex &newA
             // we need to force activation because setCurrentAnimation will have no effect
             activateCurrentAnimation();
         else
-            setCurrentAnimation(animations.count() - 1, true);
+            setCurrentAnimation(animations.size() - 1, true);
     }
 
     // and now we need to fast rewind from the current position to
@@ -396,7 +396,7 @@ void QSequentialAnimationGroupPrivate::setCurrentAnimation(int index, bool inter
     // currentAnimation.removeBindingUnlessInWrapper()
     // is not necessary here, since it is read only
 
-    index = qMin(index, animations.count() - 1);
+    index = qMin(index, animations.size() - 1);
 
     if (index == -1) {
         Q_ASSERT(animations.isEmpty());
@@ -517,7 +517,7 @@ void QSequentialAnimationGroupPrivate::animationRemoved(int index, QAbstractAnim
 
         disconnectUncontrolledAnimation(currentAnimation);
 
-        if (index < animations.count())
+        if (index < animations.size())
             setCurrentAnimation(index); //let's try to take the next one
         else if (index > 0)
             setCurrentAnimation(index - 1);
diff --git a/src/corelib/global/qlibraryinfo.cpp b/src/corelib/global/qlibraryinfo.cpp
index f88f72e64c..64fc9fff01 100644
--- a/src/corelib/global/qlibraryinfo.cpp
+++ b/src/corelib/global/qlibraryinfo.cpp
@@ -547,7 +547,7 @@ QString QLibraryInfoPrivate::path(QLibraryInfo::LibraryPath p, UsageMode usageMo
                 startIndex = ret.indexOf(u'$', startIndex);
                 if (startIndex < 0)
                     break;
-                if (ret.length() < startIndex + 3)
+                if (ret.size() < startIndex + 3)
                     break;
                 if (ret.at(startIndex + 1) != u'(') {
                     startIndex++;
@@ -559,7 +559,7 @@ QString QLibraryInfoPrivate::path(QLibraryInfo::LibraryPath p, UsageMode usageMo
                 auto envVarName = QStringView{ret}.mid(startIndex + 2, endIndex - startIndex - 2);
                 QString value = QString::fromLocal8Bit(qgetenv(envVarName.toLocal8Bit().constData()));
                 ret.replace(startIndex, endIndex - startIndex + 1, value);
-                startIndex += value.length();
+                startIndex += value.size();
             }
 
             config->endGroup();
diff --git a/src/corelib/global/qlogging.cpp b/src/corelib/global/qlogging.cpp
index e2bfbafe4e..b64099b7c9 100644
--- a/src/corelib/global/qlogging.cpp
+++ b/src/corelib/global/qlogging.cpp
@@ -1183,7 +1183,7 @@ void QMessagePattern::setPattern(const QString &pattern)
                 tokens[i] = timeTokenC;
                 int spaceIdx = lexeme.indexOf(QChar::fromLatin1(' '));
                 if (spaceIdx > 0)
-                    timeArgs.append(lexeme.mid(spaceIdx + 1, lexeme.length() - spaceIdx - 2));
+                    timeArgs.append(lexeme.mid(spaceIdx + 1, lexeme.size() - spaceIdx - 2));
                 else
                     timeArgs.append(QString());
             } else if (lexeme.startsWith(QLatin1StringView(backtraceTokenC))) {
diff --git a/src/corelib/global/qsysinfo.cpp b/src/corelib/global/qsysinfo.cpp
index a06a85b641..8ddcbb0409 100644
--- a/src/corelib/global/qsysinfo.cpp
+++ b/src/corelib/global/qsysinfo.cpp
@@ -276,19 +276,19 @@ static bool readEtcFile(QUnixOSVersion &v, const char *filename,
         line.setRawData(ptr, eol - ptr);
 
         if (line.startsWith(idKey)) {
-            ptr += idKey.length();
+            ptr += idKey.size();
             v.productType = unquote(ptr, eol);
             continue;
         }
 
         if (line.startsWith(prettyNameKey)) {
-            ptr += prettyNameKey.length();
+            ptr += prettyNameKey.size();
             v.prettyName = unquote(ptr, eol);
             continue;
         }
 
         if (line.startsWith(versionKey)) {
-            ptr += versionKey.length();
+            ptr += versionKey.size();
             v.productVersion = unquote(ptr, eol);
             continue;
         }
@@ -325,7 +325,7 @@ static bool readEtcLsbRelease(QUnixOSVersion &v)
         int fd = qt_safe_open(distrorelease, O_RDONLY);
         if (fd != -1) {
             QT_STATBUF sbuf;
-            if (QT_FSTAT(fd, &sbuf) != -1 && sbuf.st_size > v.prettyName.length()) {
+            if (QT_FSTAT(fd, &sbuf) != -1 && sbuf.st_size > v.prettyName.size()) {
                 // file apparently contains interesting information
                 QByteArray buffer(sbuf.st_size, Qt::Uninitialized);
                 buffer.resize(qt_safe_read(fd, buffer.data(), sbuf.st_size));
diff --git a/src/corelib/io/qdebug.h b/src/corelib/io/qdebug.h
index f8fd877010..6c693ad142 100644
--- a/src/corelib/io/qdebug.h
+++ b/src/corelib/io/qdebug.h
@@ -112,7 +112,7 @@ public:
     inline QDebug &operator<<(double t) { stream->ts << t; return maybeSpace(); }
     inline QDebug &operator<<(const char* t) { stream->ts << QString::fromUtf8(t); return maybeSpace(); }
     inline QDebug &operator<<(const char16_t *t)  { stream->ts << QStringView(t); return maybeSpace(); }
-    inline QDebug &operator<<(const QString & t) { putString(t.constData(), size_t(t.length())); return maybeSpace(); }
+    inline QDebug &operator<<(const QString & t) { putString(t.constData(), size_t(t.size())); return maybeSpace(); }
     inline QDebug &operator<<(QStringView s) { putString(s.data(), size_t(s.size())); return maybeSpace(); }
     inline QDebug &operator<<(QUtf8StringView s) { putByteArray(reinterpret_cast<const char*>(s.data()), s.size(), ContainsBinary); return maybeSpace(); }
     inline QDebug &operator<<(QLatin1StringView t) { putByteArray(t.latin1(), t.size(), ContainsLatin1); return maybeSpace(); }
diff --git a/src/corelib/io/qdir.cpp b/src/corelib/io/qdir.cpp
index 624efdafc9..d18f409983 100644
--- a/src/corelib/io/qdir.cpp
+++ b/src/corelib/io/qdir.cpp
@@ -144,12 +144,12 @@ inline void QDirPrivate::setPath(const QString &path)
 {
     QString p = QDir::fromNativeSeparators(path);
     if (p.endsWith(u'/')
-            && p.length() > 1
+            && p.size() > 1
 #if defined(Q_OS_WIN)
         && (!(p.length() == 3 && p.at(1).unicode() == ':' && p.at(0).isLetter()))
 #endif
     ) {
-            p.truncate(p.length() - 1);
+            p.truncate(p.size() - 1);
     }
 
     dirEntry = QFileSystemEntry(p, QFileSystemEntry::FromInternalPath());
@@ -1052,7 +1052,7 @@ Q_GLOBAL_STATIC(DirSearchPaths, dirSearchPaths)
 */
 void QDir::setSearchPaths(const QString &prefix, const QStringList &searchPaths)
 {
-    if (prefix.length() < 2) {
+    if (prefix.size() < 2) {
         qWarning("QDir::setSearchPaths: Prefix must be longer than 1 character");
         return;
     }
@@ -2303,7 +2303,7 @@ static QString qt_cleanPath(const QString &path, bool *ok)
     QString ret = qt_normalizePathSegments(name, OSSupportsUncPaths ? QDirPrivate::AllowUncPaths : QDirPrivate::DefaultNormalization, ok);
 
     // Strip away last slash except for root directories
-    if (ret.length() > 1 && ret.endsWith(u'/')) {
+    if (ret.size() > 1 && ret.endsWith(u'/')) {
 #if defined (Q_OS_WIN)
         if (!(ret.length() == 3 && ret.at(1) == u':'))
 #endif
diff --git a/src/corelib/io/qfilesystemengine_unix.cpp b/src/corelib/io/qfilesystemengine_unix.cpp
index 9036608e7d..0645952091 100644
--- a/src/corelib/io/qfilesystemengine_unix.cpp
+++ b/src/corelib/io/qfilesystemengine_unix.cpp
@@ -591,7 +591,7 @@ QFileSystemEntry QFileSystemEngine::getLinkTarget(const QFileSystemEntry &link,
     Q_CHECK_FILE_NAME(link, link);
 
     QByteArray s = qt_readlink(link.nativeFilePath().constData());
-    if (s.length() > 0) {
+    if (s.size() > 0) {
         QString ret;
         if (!data.hasFlags(QFileSystemMetaData::DirectoryType))
             fillMetaData(link, data, QFileSystemMetaData::DirectoryType);
@@ -713,13 +713,13 @@ QFileSystemEntry QFileSystemEngine::absoluteName(const QFileSystemEntry &entry)
         QFileSystemEntry cur(currentPath());
         result = cur.nativeFilePath();
     }
-    if (!orig.isEmpty() && !(orig.length() == 1 && orig[0] == '.')) {
+    if (!orig.isEmpty() && !(orig.size() == 1 && orig[0] == '.')) {
         if (!result.isEmpty() && !result.endsWith('/'))
             result.append('/');
         result.append(orig);
     }
 
-    if (result.length() == 1 && result[0] == '/')
+    if (result.size() == 1 && result[0] == '/')
         return QFileSystemEntry(result, QFileSystemEntry::FromNativePath());
     const bool isDir = result.endsWith('/');
 
@@ -1152,7 +1152,7 @@ bool QFileSystemEngine::removeDirectory(const QFileSystemEntry &entry, bool remo
 
     if (removeEmptyParents) {
         QString dirName = QDir::cleanPath(entry.filePath());
-        for (int oldslash = 0, slash=dirName.length(); slash > 0; oldslash = slash) {
+        for (int oldslash = 0, slash=dirName.size(); slash > 0; oldslash = slash) {
             const QByteArray chunk = QFile::encodeName(dirName.left(slash));
             QT_STATBUF st;
             if (QT_STAT(chunk.constData(), &st) != -1) {
diff --git a/src/corelib/io/qfsfileengine.cpp b/src/corelib/io/qfsfileengine.cpp
index 23698930c0..d924b22431 100644
--- a/src/corelib/io/qfsfileengine.cpp
+++ b/src/corelib/io/qfsfileengine.cpp
@@ -468,7 +468,7 @@ void QFSFileEnginePrivate::unmapAll()
 {
     if (!maps.isEmpty()) {
         const QList<uchar*> keys = maps.keys(); // Make a copy since unmap() modifies the map.
-        for (int i = 0; i < keys.count(); ++i)
+        for (int i = 0; i < keys.size(); ++i)
             unmap(keys.at(i));
     }
 }
diff --git a/src/corelib/io/qresource.cpp b/src/corelib/io/qresource.cpp
index 7eac497cea..5bee6c675b 100644
--- a/src/corelib/io/qresource.cpp
+++ b/src/corelib/io/qresource.cpp
@@ -779,7 +779,7 @@ int QResourceRoot::findNode(const QString &_path, const QLocale &locale) const
                 if (!root.endsWith(u'/'))
                     root += u'/';
                 if (path.size() >= root.size() && path.startsWith(root))
-                    path = path.mid(root.length() - 1);
+                    path = path.mid(root.size() - 1);
                 if (path.isEmpty())
                     path = u'/';
             }
diff --git a/src/corelib/io/qsettings.cpp b/src/corelib/io/qsettings.cpp
index d9c299d890..cf5a0c66c3 100644
--- a/src/corelib/io/qsettings.cpp
+++ b/src/corelib/io/qsettings.cpp
@@ -356,7 +356,7 @@ QVariant QSettingsPrivate::stringListToVariantList(const QStringList &l)
         const QString &str = outStringList.at(i);
 
         if (str.startsWith(u'@')) {
-            if (str.length() < 2 || str.at(1) != u'@') {
+            if (str.size() < 2 || str.at(1) != u'@') {
                 QVariantList variantList;
                 variantList.reserve(l.count());
                 for (const auto &s : l)
@@ -509,7 +509,7 @@ QVariant QSettingsPrivate::stringToVariant(const QString &s)
 
 void QSettingsPrivate::iniEscapedKey(const QString &key, QByteArray &result)
 {
-    result.reserve(result.length() + key.length() * 3 / 2);
+    result.reserve(result.size() + key.size() * 3 / 2);
     for (qsizetype i = 0; i < key.size(); ++i) {
         uint ch = key.at(i).unicode();
 
@@ -538,7 +538,7 @@ bool QSettingsPrivate::iniUnescapedKey(QByteArrayView key, QString &result)
 {
     const QString decoded = QString::fromUtf8(key);
     const qsizetype size = decoded.size();
-    result.reserve(result.length() + size);
+    result.reserve(result.size() + size);
     qsizetype i = 0;
     bool lowercaseOnly = true;
     while (i < size) {
@@ -731,7 +731,7 @@ StSkipSpaces:
     // fallthrough
 
 StNormal:
-    qsizetype chopLimit = stringResult.length();
+    qsizetype chopLimit = stringResult.size();
     while (i < str.size()) {
         switch (str.at(i)) {
         case '\\':
@@ -769,7 +769,7 @@ StNormal:
             } else {
                 // the character is skipped
             }
-            chopLimit = stringResult.length();
+            chopLimit = stringResult.size();
             break;
         case '"':
             ++i;
@@ -856,7 +856,7 @@ end:
 
 QStringList QSettingsPrivate::splitArgs(const QString &s, qsizetype idx)
 {
-    qsizetype l = s.length();
+    qsizetype l = s.size();
     Q_ASSERT(l > 0);
     Q_ASSERT(s.at(idx) == u'(');
     Q_ASSERT(s.at(l - 1) == u')');
diff --git a/src/corelib/io/qstandardpaths_unix.cpp b/src/corelib/io/qstandardpaths_unix.cpp
index e5122ff3b6..b94dd6a18d 100644
--- a/src/corelib/io/qstandardpaths_unix.cpp
+++ b/src/corelib/io/qstandardpaths_unix.cpp
@@ -269,7 +269,7 @@ QString QStandardPaths::writableLocation(StandardLocation type)
                     result = QDir::homePath() + value.mid(5);
                 else
                     result = value.toString();
-                if (result.length() > 1 && result.endsWith(u'/'))
+                if (result.size() > 1 && result.endsWith(u'/'))
                     result.chop(1);
             }
         }
diff --git a/src/corelib/io/qstorageinfo_unix.cpp b/src/corelib/io/qstorageinfo_unix.cpp
index 89b6dfea9d..5f3fa32482 100644
--- a/src/corelib/io/qstorageinfo_unix.cpp
+++ b/src/corelib/io/qstorageinfo_unix.cpp
@@ -711,8 +711,8 @@ void QStorageInfoPrivate::initRootPath()
         const QString mountDir = it.rootPath();
         const QByteArray fsName = it.fileSystemType();
         // we try to find most suitable entry
-        if (isParentOf(mountDir, oldRootPath) && maxLength < mountDir.length()) {
-            maxLength = mountDir.length();
+        if (isParentOf(mountDir, oldRootPath) && maxLength < mountDir.size()) {
+            maxLength = mountDir.size();
             rootPath = mountDir;
             device = it.device();
             fileSystemType = fsName;
diff --git a/src/corelib/io/qtemporaryfile.cpp b/src/corelib/io/qtemporaryfile.cpp
index 44c45a1cad..8890f3dfad 100644
--- a/src/corelib/io/qtemporaryfile.cpp
+++ b/src/corelib/io/qtemporaryfile.cpp
@@ -45,7 +45,7 @@ QTemporaryFileName::QTemporaryFileName(const QString &templateName)
 {
     // Ensure there is a placeholder mask
     QString qfilename = QDir::fromNativeSeparators(templateName);
-    uint phPos = qfilename.length();
+    uint phPos = qfilename.size();
     uint phLength = 0;
 
     while (phPos != 0) {
diff --git a/src/corelib/io/qurl.cpp b/src/corelib/io/qurl.cpp
index 14d89a9ea8..3cebb68561 100644
--- a/src/corelib/io/qurl.cpp
+++ b/src/corelib/io/qurl.cpp
@@ -510,7 +510,7 @@ public:
     ErrorCode validityError(QString *source = nullptr, qsizetype *position = nullptr) const;
     bool validateComponent(Section section, const QString &input, qsizetype begin, qsizetype end);
     bool validateComponent(Section section, const QString &input)
-    { return validateComponent(section, input, 0, input.length()); }
+    { return validateComponent(section, input, 0, input.size()); }
 
     // no QString scheme() const;
     void appendAuthority(QString &appendTo, QUrl::FormattingOptions options, Section appendingTo) const;
@@ -1191,7 +1191,7 @@ static const QChar *parseIpFuture(QString &host, const QChar *begin, const QChar
 
         // uppercase the version, if necessary
         if (begin[2].unicode() >= 'a')
-            host[host.length() - 2] = QChar{begin[2].unicode() - 0x20};
+            host[host.size() - 2] = QChar{begin[2].unicode() - 0x20};
 
         begin += 4;
         --end;
@@ -1341,7 +1341,7 @@ QUrlPrivate::setHost(const QString &value, qsizetype from, qsizetype iend, QUrl:
         }
 
         // recurse
-        return setHost(s, 0, s.length(), QUrl::StrictMode);
+        return setHost(s, 0, s.size(), QUrl::StrictMode);
     }
 
     s = qt_ACE_do(value.mid(from, iend - from), NormalizeAce, ForbidLeadingDot, {});
@@ -1377,7 +1377,7 @@ inline void QUrlPrivate::parse(const QString &url, QUrl::ParsingMode parsingMode
     qsizetype colon = -1;
     qsizetype question = -1;
     qsizetype hash = -1;
-    const qsizetype len = url.length();
+    const qsizetype len = url.size();
     const QChar *const begin = url.constData();
     const ushort *const data = reinterpret_cast<const ushort *>(begin);
 
@@ -1628,7 +1628,7 @@ inline QUrlPrivate::ErrorCode QUrlPrivate::validityError(QString *source, qsizet
     if (path.isEmpty())
         return NoError;
     if (path.at(0) == u'/') {
-        if (hasAuthority() || path.length() == 1 || path.at(1) != u'/')
+        if (hasAuthority() || path.size() == 1 || path.at(1) != u'/')
             return NoError;
         if (source) {
             *source = path;
@@ -1648,7 +1648,7 @@ inline QUrlPrivate::ErrorCode QUrlPrivate::validityError(QString *source, qsizet
         return NoError;
 
     // check for a path of "text:text/"
-    for (qsizetype i = 0; i < path.length(); ++i) {
+    for (qsizetype i = 0; i < path.size(); ++i) {
         ushort c = path.at(i).unicode();
         if (c == '/') {
             // found the slash before the colon
@@ -1956,7 +1956,7 @@ void QUrl::setScheme(const QString &scheme)
         d->flags &= ~QUrlPrivate::IsLocalFile;
         d->scheme.clear();
     } else {
-        d->setScheme(scheme, scheme.length(), /* do set error */ true);
+        d->setScheme(scheme, scheme.size(), /* do set error */ true);
     }
 }
 
@@ -2016,7 +2016,7 @@ void QUrl::setAuthority(const QString &authority, ParsingMode mode)
         return;
     }
 
-    d->setAuthority(authority, 0, authority.length(), mode);
+    d->setAuthority(authority, 0, authority.size(), mode);
     if (authority.isNull()) {
         // QUrlPrivate::setAuthority cleared almost everything
         // but it leaves the Host bit set
@@ -2087,7 +2087,7 @@ void QUrl::setUserInfo(const QString &userInfo, ParsingMode mode)
         return;
     }
 
-    d->setUserInfo(trimmed, 0, trimmed.length());
+    d->setUserInfo(trimmed, 0, trimmed.size());
     if (userInfo.isNull()) {
         // QUrlPrivate::setUserInfo cleared almost everything
         // but it leaves the UserName bit set
@@ -2159,7 +2159,7 @@ void QUrl::setUserName(const QString &userName, ParsingMode mode)
         mode = TolerantMode;
     }
 
-    d->setUserName(data, 0, data.length());
+    d->setUserName(data, 0, data.size());
     if (userName.isNull())
         d->sectionIsPresent &= ~QUrlPrivate::UserName;
     else if (mode == StrictMode && !d->validateComponent(QUrlPrivate::UserName, userName))
@@ -2222,7 +2222,7 @@ void QUrl::setPassword(const QString &password, ParsingMode mode)
         mode = TolerantMode;
     }
 
-    d->setPassword(data, 0, data.length());
+    d->setPassword(data, 0, data.size());
     if (password.isNull())
         d->sectionIsPresent &= ~QUrlPrivate::Password;
     else if (mode == StrictMode && !d->validateComponent(QUrlPrivate::Password, password))
@@ -2284,7 +2284,7 @@ void QUrl::setHost(const QString &host, ParsingMode mode)
         mode = TolerantMode;
     }
 
-    if (d->setHost(data, 0, data.length(), mode)) {
+    if (d->setHost(data, 0, data.size(), mode)) {
         if (host.isNull())
             d->sectionIsPresent &= ~QUrlPrivate::Host;
     } else if (!data.startsWith(u'[')) {
@@ -2293,7 +2293,7 @@ void QUrl::setHost(const QString &host, ParsingMode mode)
 
         data.prepend(u'[');
         data.append(u']');
-        if (!d->setHost(data, 0, data.length(), mode)) {
+        if (!d->setHost(data, 0, data.size(), mode)) {
             // failed again
             if (data.contains(u':')) {
                 // source data contains ':', so it's an IPv6 error
@@ -2330,7 +2330,7 @@ QString QUrl::host(ComponentFormattingOptions options) const
     if (d) {
         d->appendHost(result, options);
         if (result.startsWith(u'['))
-            result = result.mid(1, result.length() - 2);
+            result = result.mid(1, result.size() - 2);
     }
     return result;
 }
@@ -2409,7 +2409,7 @@ void QUrl::setPath(const QString &path, ParsingMode mode)
         mode = TolerantMode;
     }
 
-    d->setPath(data, 0, data.length());
+    d->setPath(data, 0, data.size());
 
     // optimized out, since there is no path delimiter
 //    if (path.isNull())
@@ -2545,7 +2545,7 @@ void QUrl::setQuery(const QString &query, ParsingMode mode)
         mode = TolerantMode;
     }
 
-    d->setQuery(data, 0, data.length());
+    d->setQuery(data, 0, data.size());
     if (query.isNull())
         d->sectionIsPresent &= ~QUrlPrivate::Query;
     else if (mode == StrictMode && !d->validateComponent(QUrlPrivate::Query, query))
@@ -2643,7 +2643,7 @@ void QUrl::setFragment(const QString &fragment, ParsingMode mode)
         mode = TolerantMode;
     }
 
-    d->setFragment(data, 0, data.length());
+    d->setFragment(data, 0, data.size());
     if (fragment.isNull())
         d->sectionIsPresent &= ~QUrlPrivate::Fragment;
     else if (mode == StrictMode && !d->validateComponent(QUrlPrivate::Fragment, fragment))
@@ -2937,7 +2937,7 @@ QUrl QUrl::adjusted(QUrl::FormattingOptions options) const
         that.detach();
         QString path;
         d->appendPath(path, options | FullyEncoded, QUrlPrivate::Path);
-        that.d->setPath(path, 0, path.length());
+        that.d->setPath(path, 0, path.size());
     }
     return that;
 }
@@ -3346,7 +3346,7 @@ QUrl QUrl::fromLocalFile(const QString &localFile)
     QString deslashified = fromNativeSeparators(localFile);
 
     // magic for drives on windows
-    if (deslashified.length() > 1 && deslashified.at(1) == u':' && deslashified.at(0) != u'/') {
+    if (deslashified.size() > 1 && deslashified.at(1) == u':' && deslashified.at(0) != u'/') {
         deslashified.prepend(u'/');
     } else if (deslashified.startsWith("//"_L1)) {
         // magic for shared drive on windows
@@ -3367,7 +3367,7 @@ QUrl QUrl::fromLocalFile(const QString &localFile)
             // Path hostname is not a valid URL host, so set it entirely in the path
             // (by leaving deslashified unchanged)
         } else if (indexOfPath > 2) {
-            deslashified = deslashified.right(deslashified.length() - indexOfPath);
+            deslashified = deslashified.right(deslashified.size() - indexOfPath);
         } else {
             deslashified.clear();
         }
@@ -3431,16 +3431,16 @@ bool QUrl::isParentOf(const QUrl &childUrl) const
     if (!d)
         return ((childUrl.scheme().isEmpty())
             && (childUrl.authority().isEmpty())
-            && childPath.length() > 0 && childPath.at(0) == u'/');
+            && childPath.size() > 0 && childPath.at(0) == u'/');
 
     QString ourPath = path();
 
     return ((childUrl.scheme().isEmpty() || d->scheme == childUrl.scheme())
             && (childUrl.authority().isEmpty() || authority() == childUrl.authority())
             &&  childPath.startsWith(ourPath)
-            && ((ourPath.endsWith(u'/') && childPath.length() > ourPath.length())
-                || (!ourPath.endsWith(u'/') && childPath.length() > ourPath.length()
-                    && childPath.at(ourPath.length()) == u'/')));
+            && ((ourPath.endsWith(u'/') && childPath.size() > ourPath.size())
+                || (!ourPath.endsWith(u'/') && childPath.size() > ourPath.size()
+                    && childPath.at(ourPath.size()) == u'/')));
 }
 
 
@@ -3488,7 +3488,7 @@ QDebug operator<<(QDebug d, const QUrl &url)
 
 static QString errorMessage(QUrlPrivate::ErrorCode errorCode, const QString &errorSource, qsizetype errorPosition)
 {
-    QChar c = size_t(errorPosition) < size_t(errorSource.length()) ?
+    QChar c = size_t(errorPosition) < size_t(errorSource.size()) ?
                 errorSource.at(errorPosition) : QChar(QChar::Null);
 
     switch (errorCode) {
diff --git a/src/corelib/io/qurlidna.cpp b/src/corelib/io/qurlidna.cpp
index 04b9a25886..c63a25125b 100644
--- a/src/corelib/io/qurlidna.cpp
+++ b/src/corelib/io/qurlidna.cpp
@@ -177,7 +177,7 @@ Q_AUTOTEST_EXPORT QString qt_punycodeDecoder(const QString &pc)
     // Do not try to decode strings longer than allowable for a domain label.
     // Non-ASCII strings are not allowed here anyway, so there is no need
     // to account for surrogates.
-    if (pc.length() > MaxDomainLabelLength)
+    if (pc.size() > MaxDomainLabelLength)
         return QString();
 
     // strip any ACE prefix
@@ -709,7 +709,7 @@ bool DomainValidityChecker::checkLabel(const QString &label, QUrl::AceProcessing
     if (label != label.normalized(QString::NormalizationForm_C))
         return false;
 
-    if (label.length() >= 4) {
+    if (label.size() >= 4) {
         // This assumes that the first two characters are in BMP, but that's ok
         // because non-BMP characters are unlikely to be used for specifying
         // future extensions.
diff --git a/src/corelib/io/qurlquery.cpp b/src/corelib/io/qurlquery.cpp
index ce8ed6414d..002ff5a38e 100644
--- a/src/corelib/io/qurlquery.cpp
+++ b/src/corelib/io/qurlquery.cpp
@@ -515,7 +515,7 @@ QString QUrlQuery::query(QUrl::ComponentFormattingOptions encoding) const
     {
         int size = 0;
         for ( ; it != end; ++it)
-            size += it->first.length() + 1 + it->second.length() + 1;
+            size += it->first.size() + 1 + it->second.size() + 1;
         result.reserve(size + size / 4);
     }
 
diff --git a/src/corelib/itemmodels/qabstractitemmodel.cpp b/src/corelib/itemmodels/qabstractitemmodel.cpp
index fcf6e69534..e6991dd7b6 100644
--- a/src/corelib/itemmodels/qabstractitemmodel.cpp
+++ b/src/corelib/itemmodels/qabstractitemmodel.cpp
@@ -840,13 +840,13 @@ void QAbstractItemModelPrivate::removePersistentIndexData(QPersistentModelIndexD
         Q_UNUSED(removed);
     }
     // make sure our optimization still works
-    for (int i = persistent.moved.count() - 1; i >= 0; --i) {
+    for (int i = persistent.moved.size() - 1; i >= 0; --i) {
         int idx = persistent.moved.at(i).indexOf(data);
         if (idx >= 0)
             persistent.moved[i].remove(idx);
     }
     // update the references to invalidated persistent indexes
-    for (int i = persistent.invalidated.count() - 1; i >= 0; --i) {
+    for (int i = persistent.invalidated.size() - 1; i >= 0; --i) {
         int idx = persistent.invalidated.at(i).indexOf(data);
         if (idx >= 0)
             persistent.invalidated[i].remove(idx);
@@ -2775,15 +2775,15 @@ bool QAbstractItemModel::decodeData(int row, int column, const QModelIndex &pare
 
     // Compute the number of continuous rows upon insertion and modify the rows to match
     QList<int> rowsToInsert(bottom + 1);
-    for (int i = 0; i < rows.count(); ++i)
+    for (int i = 0; i < rows.size(); ++i)
         rowsToInsert[rows.at(i)] = 1;
-    for (int i = 0; i < rowsToInsert.count(); ++i) {
+    for (int i = 0; i < rowsToInsert.size(); ++i) {
         if (rowsToInsert.at(i) == 1){
             rowsToInsert[i] = dragRowCount;
             ++dragRowCount;
         }
     }
-    for (int i = 0; i < rows.count(); ++i)
+    for (int i = 0; i < rows.size(); ++i)
         rows[i] = top + rowsToInsert.at(rows.at(i));
 
     QBitArray isWrittenTo(dragRowCount * dragColumnCount);
@@ -3473,7 +3473,7 @@ QModelIndexList QAbstractItemModel::persistentIndexList() const
 {
     Q_D(const QAbstractItemModel);
     QModelIndexList result;
-    result.reserve(d->persistent.indexes.count());
+    result.reserve(d->persistent.indexes.size());
     for (auto *data : qAsConst(d->persistent.indexes))
         result.append(data->index);
     return result;
diff --git a/src/corelib/itemmodels/qconcatenatetablesproxymodel.cpp b/src/corelib/itemmodels/qconcatenatetablesproxymodel.cpp
index 7ef0bbc7a7..f2e74edf19 100644
--- a/src/corelib/itemmodels/qconcatenatetablesproxymodel.cpp
+++ b/src/corelib/itemmodels/qconcatenatetablesproxymodel.cpp
@@ -688,7 +688,7 @@ void QConcatenateTablesProxyModelPrivate::updateColumnCount()
 int QConcatenateTablesProxyModelPrivate::columnCountAfterChange(const QAbstractItemModel *model, int newCount) const
 {
     int newColumnCount = 0;
-    for (int i = 0; i < m_models.count(); ++i) {
+    for (int i = 0; i < m_models.size(); ++i) {
         const QAbstractItemModel *mod = m_models.at(i);
         const int colCount = mod == model ? newCount : mod->columnCount();
         if (i == 0)
diff --git a/src/corelib/itemmodels/qitemselectionmodel.cpp b/src/corelib/itemmodels/qitemselectionmodel.cpp
index 7da3a9b003..fb134f7878 100644
--- a/src/corelib/itemmodels/qitemselectionmodel.cpp
+++ b/src/corelib/itemmodels/qitemselectionmodel.cpp
@@ -878,7 +878,7 @@ static QItemSelection mergeRowLengths(const QList<QPair<QPersistentModelIndex, u
 
     QItemSelection result;
     int i = 0;
-    while (i < rowLengths.count()) {
+    while (i < rowLengths.size()) {
         const QPersistentModelIndex &tl = rowLengths.at(i).first;
         if (!tl.isValid()) {
             ++i;
@@ -886,7 +886,7 @@ static QItemSelection mergeRowLengths(const QList<QPair<QPersistentModelIndex, u
         }
         QPersistentModelIndex br = tl;
         const uint length = rowLengths.at(i).second;
-        while (++i < rowLengths.count()) {
+        while (++i < rowLengths.size()) {
             const QPersistentModelIndex &next = rowLengths.at(i).first;
             if (!next.isValid())
                 continue;
@@ -916,7 +916,7 @@ static QItemSelection mergeIndexes(const QList<QPersistentModelIndex> &indexes)
     QItemSelection colSpans;
     // merge columns
     int i = 0;
-    while (i < indexes.count()) {
+    while (i < indexes.size()) {
         const QPersistentModelIndex &tl = indexes.at(i);
         if (!tl.isValid()) {
             ++i;
@@ -926,7 +926,7 @@ static QItemSelection mergeIndexes(const QList<QPersistentModelIndex> &indexes)
         QModelIndex brParent = br.parent();
         int brRow = br.row();
         int brColumn = br.column();
-        while (++i < indexes.count()) {
+        while (++i < indexes.size()) {
             const QPersistentModelIndex &next = indexes.at(i);
             if (!next.isValid())
                 continue;
diff --git a/src/corelib/itemmodels/qsortfilterproxymodel.cpp b/src/corelib/itemmodels/qsortfilterproxymodel.cpp
index 27cf624c51..251b632e67 100644
--- a/src/corelib/itemmodels/qsortfilterproxymodel.cpp
+++ b/src/corelib/itemmodels/qsortfilterproxymodel.cpp
@@ -959,12 +959,12 @@ void QSortFilterProxyModelPrivate::source_items_inserted(
         it = create_mapping(source_parent);
         Mapping *m = it.value();
         QModelIndex proxy_parent = q->mapFromSource(source_parent);
-        if (m->source_rows.count() > 0) {
-            q->beginInsertRows(proxy_parent, 0, m->source_rows.count() - 1);
+        if (m->source_rows.size() > 0) {
+            q->beginInsertRows(proxy_parent, 0, m->source_rows.size() - 1);
             q->endInsertRows();
         }
-        if (m->source_columns.count() > 0) {
-            q->beginInsertColumns(proxy_parent, 0, m->source_columns.count() - 1);
+        if (m->source_columns.size() > 0) {
+            q->beginInsertColumns(proxy_parent, 0, m->source_columns.size() - 1);
             q->endInsertColumns();
         }
         return;
@@ -1190,7 +1190,7 @@ void QSortFilterProxyModelPrivate::proxy_item_range(
 {
     proxy_low = INT_MAX;
     proxy_high = INT_MIN;
-    for (int i = 0; i < source_items.count(); ++i) {
+    for (int i = 0; i < source_items.size(); ++i) {
         int proxy_item = source_to_proxy.at(source_items.at(i));
         Q_ASSERT(proxy_item != -1);
         if (proxy_item < proxy_low)
@@ -1223,7 +1223,7 @@ QModelIndexPairList QSortFilterProxyModelPrivate::store_persistent_indexes() con
 {
     Q_Q(const QSortFilterProxyModel);
     QModelIndexPairList source_indexes;
-    source_indexes.reserve(persistent.indexes.count());
+    source_indexes.reserve(persistent.indexes.size());
     for (const QPersistentModelIndexData *data : qAsConst(persistent.indexes)) {
         const QModelIndex &proxy_index = data->index;
         QModelIndex source_index = q->mapToSource(proxy_index);
@@ -1327,7 +1327,7 @@ QSet<int> QSortFilterProxyModelPrivate::handle_filter_changed(
     Q_Q(QSortFilterProxyModel);
     // Figure out which mapped items to remove
     QList<int> source_items_remove;
-    for (int i = 0; i < proxy_to_source.count(); ++i) {
+    for (int i = 0; i < proxy_to_source.size(); ++i) {
         const int source_item = proxy_to_source.at(i);
         if ((orient == Qt::Vertical)
             ? !filterAcceptsRowInternal(source_item, source_parent)
@@ -1435,7 +1435,7 @@ void QSortFilterProxyModelPrivate::_q_sourceDataChanged(const QModelIndex &sourc
         QList<int> source_rows_insert;
         QList<int> source_rows_change;
         QList<int> source_rows_resort;
-        int end = qMin(source_bottom_right.row(), m->proxy_rows.count() - 1);
+        int end = qMin(source_bottom_right.row(), m->proxy_rows.size() - 1);
         for (int source_row = source_top_left.row(); source_row <= end; ++source_row) {
             if (dynamic_sortfilter && !change_in_unmapped_parent) {
                 if (m->proxy_rows.at(source_row) != -1) {
@@ -2155,7 +2155,7 @@ QModelIndex QSortFilterProxyModel::index(int row, int column, const QModelIndex
 
     QModelIndex source_parent = mapToSource(parent); // parent is already mapped at this point
     IndexMap::const_iterator it = d->create_mapping(source_parent); // but make sure that the children are mapped
-    if (it.value()->source_rows.count() <= row || it.value()->source_columns.count() <= column)
+    if (it.value()->source_rows.size() <= row || it.value()->source_columns.size() <= column)
         return QModelIndex();
 
     return d->create_index(row, column, it);
@@ -2186,7 +2186,7 @@ QModelIndex QSortFilterProxyModel::sibling(int row, int column, const QModelInde
         return QModelIndex();
 
     const IndexMap::const_iterator it = d->index_to_iterator(idx);
-    if (it.value()->source_rows.count() <= row || it.value()->source_columns.count() <= column)
+    if (it.value()->source_rows.size() <= row || it.value()->source_columns.size() <= column)
         return QModelIndex();
 
     return d->create_index(row, column, it);
@@ -2202,7 +2202,7 @@ int QSortFilterProxyModel::rowCount(const QModelIndex &parent) const
     if (parent.isValid() && !source_parent.isValid())
         return 0;
     IndexMap::const_iterator it = d->create_mapping(source_parent);
-    return it.value()->source_rows.count();
+    return it.value()->source_rows.size();
 }
 
 /*!
@@ -2215,7 +2215,7 @@ int QSortFilterProxyModel::columnCount(const QModelIndex &parent) const
     if (parent.isValid() && !source_parent.isValid())
         return 0;
     IndexMap::const_iterator it = d->create_mapping(source_parent);
-    return it.value()->source_columns.count();
+    return it.value()->source_columns.size();
 }
 
 /*!
@@ -2234,7 +2234,7 @@ bool QSortFilterProxyModel::hasChildren(const QModelIndex &parent) const
         return true; //we assume we might have children that can be fetched
 
     QSortFilterProxyModelPrivate::Mapping *m = d->create_mapping(source_parent).value();
-    return m->source_rows.count() != 0 && m->source_columns.count() != 0;
+    return m->source_rows.size() != 0 && m->source_columns.size() != 0;
 }
 
 /*!
@@ -2268,15 +2268,15 @@ QVariant QSortFilterProxyModel::headerData(int section, Qt::Orientation orientat
 {
     Q_D(const QSortFilterProxyModel);
     IndexMap::const_iterator it = d->create_mapping(QModelIndex());
-    if (it.value()->source_rows.count() * it.value()->source_columns.count() > 0)
+    if (it.value()->source_rows.size() * it.value()->source_columns.size() > 0)
         return QAbstractProxyModel::headerData(section, orientation, role);
     int source_section;
     if (orientation == Qt::Vertical) {
-        if (section < 0 || section >= it.value()->source_rows.count())
+        if (section < 0 || section >= it.value()->source_rows.size())
             return QVariant();
         source_section = it.value()->source_rows.at(section);
     } else {
-        if (section < 0 || section >= it.value()->source_columns.count())
+        if (section < 0 || section >= it.value()->source_columns.size())
             return QVariant();
         source_section = it.value()->source_columns.at(section);
     }
@@ -2291,15 +2291,15 @@ bool QSortFilterProxyModel::setHeaderData(int section, Qt::Orientation orientati
 {
     Q_D(QSortFilterProxyModel);
     IndexMap::const_iterator it = d->create_mapping(QModelIndex());
-    if (it.value()->source_rows.count() * it.value()->source_columns.count() > 0)
+    if (it.value()->source_rows.size() * it.value()->source_columns.size() > 0)
         return QAbstractProxyModel::setHeaderData(section, orientation, value, role);
     int source_section;
     if (orientation == Qt::Vertical) {
-        if (section < 0 || section >= it.value()->source_rows.count())
+        if (section < 0 || section >= it.value()->source_rows.size())
             return false;
         source_section = it.value()->source_rows.at(section);
     } else {
-        if (section < 0 || section >= it.value()->source_columns.count())
+        if (section < 0 || section >= it.value()->source_columns.size())
             return false;
         source_section = it.value()->source_columns.at(section);
     }
@@ -2359,10 +2359,10 @@ bool QSortFilterProxyModel::insertRows(int row, int count, const QModelIndex &pa
     if (parent.isValid() && !source_parent.isValid())
         return false;
     QSortFilterProxyModelPrivate::Mapping *m = d->create_mapping(source_parent).value();
-    if (row > m->source_rows.count())
+    if (row > m->source_rows.size())
         return false;
-    int source_row = (row >= m->source_rows.count()
-                      ? m->proxy_rows.count()
+    int source_row = (row >= m->source_rows.size()
+                      ? m->proxy_rows.size()
                       : m->source_rows.at(row));
     return d->model->insertRows(source_row, count, source_parent);
 }
@@ -2379,10 +2379,10 @@ bool QSortFilterProxyModel::insertColumns(int column, int count, const QModelInd
     if (parent.isValid() && !source_parent.isValid())
         return false;
     QSortFilterProxyModelPrivate::Mapping *m = d->create_mapping(source_parent).value();
-    if (column > m->source_columns.count())
+    if (column > m->source_columns.size())
         return false;
-    int source_column = (column >= m->source_columns.count()
-                         ? m->proxy_columns.count()
+    int source_column = (column >= m->source_columns.size()
+                         ? m->proxy_columns.size()
                          : m->source_columns.at(column));
     return d->model->insertColumns(source_column, count, source_parent);
 }
@@ -2399,10 +2399,10 @@ bool QSortFilterProxyModel::removeRows(int row, int count, const QModelIndex &pa
     if (parent.isValid() && !source_parent.isValid())
         return false;
     QSortFilterProxyModelPrivate::Mapping *m = d->create_mapping(source_parent).value();
-    if (row + count > m->source_rows.count())
+    if (row + count > m->source_rows.size())
         return false;
     if ((count == 1)
-        || ((d->source_sort_column < 0) && (m->proxy_rows.count() == m->source_rows.count()))) {
+        || ((d->source_sort_column < 0) && (m->proxy_rows.size() == m->source_rows.size()))) {
         int source_row = m->source_rows.at(row);
         return d->model->removeRows(source_row, count, source_parent);
     }
@@ -2414,7 +2414,7 @@ bool QSortFilterProxyModel::removeRows(int row, int count, const QModelIndex &pa
         rows.append(m->source_rows.at(i));
     std::sort(rows.begin(), rows.end());
 
-    int pos = rows.count() - 1;
+    int pos = rows.size() - 1;
     bool ok = true;
     while (pos >= 0) {
         const int source_end = rows.at(pos--);
@@ -2441,9 +2441,9 @@ bool QSortFilterProxyModel::removeColumns(int column, int count, const QModelInd
     if (parent.isValid() && !source_parent.isValid())
         return false;
     QSortFilterProxyModelPrivate::Mapping *m = d->create_mapping(source_parent).value();
-    if (column + count > m->source_columns.count())
+    if (column + count > m->source_columns.size())
         return false;
-    if ((count == 1) || (m->proxy_columns.count() == m->source_columns.count())) {
+    if ((count == 1) || (m->proxy_columns.size() == m->source_columns.size())) {
         int source_column = m->source_columns.at(column);
         return d->model->removeColumns(source_column, count, source_parent);
     }
@@ -2453,7 +2453,7 @@ bool QSortFilterProxyModel::removeColumns(int column, int count, const QModelInd
     for (int i = column; i < column + count; ++i)
         columns.append(m->source_columns.at(i));
 
-    int pos = columns.count() - 1;
+    int pos = columns.size() - 1;
     bool ok = true;
     while (pos >= 0) {
         const int source_end = columns.at(pos--);
diff --git a/src/corelib/kernel/qabstracteventdispatcher.cpp b/src/corelib/kernel/qabstracteventdispatcher.cpp
index 84a688a9e4..3001e3269b 100644
--- a/src/corelib/kernel/qabstracteventdispatcher.cpp
+++ b/src/corelib/kernel/qabstracteventdispatcher.cpp
@@ -382,7 +382,7 @@ void QAbstractEventDispatcher::installNativeEventFilter(QAbstractNativeEventFilt
 void QAbstractEventDispatcher::removeNativeEventFilter(QAbstractNativeEventFilter *filter)
 {
     Q_D(QAbstractEventDispatcher);
-    for (int i = 0; i < d->eventFilters.count(); ++i) {
+    for (int i = 0; i < d->eventFilters.size(); ++i) {
         if (d->eventFilters.at(i) == filter) {
             d->eventFilters[i] = nullptr;
             break;
diff --git a/src/corelib/kernel/qcoreapplication.cpp b/src/corelib/kernel/qcoreapplication.cpp
index 4d69ca9a17..798ac8fdd7 100644
--- a/src/corelib/kernel/qcoreapplication.cpp
+++ b/src/corelib/kernel/qcoreapplication.cpp
@@ -2153,7 +2153,7 @@ static void replacePercentN(QString *result, int n)
                 fmt = fmt.arg(n);
                 ++len;
                 result->replace(percentPos, len, fmt);
-                len = fmt.length();
+                len = fmt.size();
             }
         }
     }
diff --git a/src/corelib/kernel/qeventdispatcher_glib.cpp b/src/corelib/kernel/qeventdispatcher_glib.cpp
index b5bd21c8ab..c644dd35d8 100644
--- a/src/corelib/kernel/qeventdispatcher_glib.cpp
+++ b/src/corelib/kernel/qeventdispatcher_glib.cpp
@@ -41,7 +41,7 @@ static gboolean socketNotifierSourceCheck(GSource *source)
     GSocketNotifierSource *src = reinterpret_cast<GSocketNotifierSource *>(source);
 
     bool pending = false;
-    for (int i = 0; !pending && i < src->pollfds.count(); ++i) {
+    for (int i = 0; !pending && i < src->pollfds.size(); ++i) {
         GPollFDWithQSocketNotifier *p = src->pollfds.at(i);
 
         if (p->pollfd.revents & G_IO_NVAL) {
@@ -65,7 +65,7 @@ static gboolean socketNotifierSourceDispatch(GSource *source, GSourceFunc, gpoin
     QEvent event(QEvent::SockAct);
 
     GSocketNotifierSource *src = reinterpret_cast<GSocketNotifierSource *>(source);
-    for (src->activeNotifierPos = 0; src->activeNotifierPos < src->pollfds.count();
+    for (src->activeNotifierPos = 0; src->activeNotifierPos < src->pollfds.size();
          ++src->activeNotifierPos) {
         GPollFDWithQSocketNotifier *p = src->pollfds.at(src->activeNotifierPos);
 
@@ -348,7 +348,7 @@ QEventDispatcherGlib::~QEventDispatcherGlib()
     d->idleTimerSource = nullptr;
 
     // destroy socket notifier source
-    for (int i = 0; i < d->socketNotifierSource->pollfds.count(); ++i) {
+    for (int i = 0; i < d->socketNotifierSource->pollfds.size(); ++i) {
         GPollFDWithQSocketNotifier *p = d->socketNotifierSource->pollfds[i];
         g_source_remove_poll(&d->socketNotifierSource->source, &p->pollfd);
         delete p;
@@ -458,7 +458,7 @@ void QEventDispatcherGlib::unregisterSocketNotifier(QSocketNotifier *notifier)
 
     Q_D(QEventDispatcherGlib);
 
-    for (int i = 0; i < d->socketNotifierSource->pollfds.count(); ++i) {
+    for (int i = 0; i < d->socketNotifierSource->pollfds.size(); ++i) {
         GPollFDWithQSocketNotifier *p = d->socketNotifierSource->pollfds.at(i);
         if (p->socketNotifier == notifier) {
             // found it
diff --git a/src/corelib/kernel/qobject.cpp b/src/corelib/kernel/qobject.cpp
index 2e05a2666e..6bfa7619db 100644
--- a/src/corelib/kernel/qobject.cpp
+++ b/src/corelib/kernel/qobject.cpp
@@ -2303,7 +2303,7 @@ void QObject::removeEventFilter(QObject *obj)
 {
     Q_D(QObject);
     if (d->extraData) {
-        for (int i = 0; i < d->extraData->eventFilters.count(); ++i) {
+        for (int i = 0; i < d->extraData->eventFilters.size(); ++i) {
             if (d->extraData->eventFilters.at(i) == obj)
                 d->extraData->eventFilters[i] = nullptr;
         }
diff --git a/src/corelib/kernel/qtranslator.cpp b/src/corelib/kernel/qtranslator.cpp
index f6f7ec12d1..85e69ea2a1 100644
--- a/src/corelib/kernel/qtranslator.cpp
+++ b/src/corelib/kernel/qtranslator.cpp
@@ -449,7 +449,7 @@ bool QTranslator::load(const QString & filename, const QString & directory,
     QString prefix;
     if (QFileInfo(filename).isRelative()) {
         prefix = directory;
-        if (prefix.length() && !prefix.endsWith(u'/'))
+        if (prefix.size() && !prefix.endsWith(u'/'))
             prefix += u'/';
     }
 
@@ -472,7 +472,7 @@ bool QTranslator::load(const QString & filename, const QString & directory,
             break;
 
         int rightmost = 0;
-        for (int i = 0; i < (int)delims.length(); i++) {
+        for (int i = 0; i < (int)delims.size(); i++) {
             int k = fname.lastIndexOf(delims[i]);
             if (k > rightmost)
                 rightmost = k;
@@ -914,7 +914,7 @@ end:
     if (!tn)
         return QString();
     QString str(tn_length / 2, Qt::Uninitialized);
-    qFromBigEndian<ushort>(tn, str.length(), str.data());
+    qFromBigEndian<ushort>(tn, str.size(), str.data());
     return str;
 }
 
diff --git a/src/corelib/mimetypes/qmimeglobpattern.cpp b/src/corelib/mimetypes/qmimeglobpattern.cpp
index f991d15b6c..381b635b90 100644
--- a/src/corelib/mimetypes/qmimeglobpattern.cpp
+++ b/src/corelib/mimetypes/qmimeglobpattern.cpp
@@ -34,9 +34,9 @@ void QMimeGlobMatchResult::addMatch(const QString &mimeType, int weight, const Q
     bool replace = weight > m_weight;
     if (!replace) {
         // Compare the length of the match
-        if (pattern.length() < m_matchingPatternLength)
+        if (pattern.size() < m_matchingPatternLength)
             return; // too short, ignore
-        else if (pattern.length() > m_matchingPatternLength) {
+        else if (pattern.size() > m_matchingPatternLength) {
             // longer: clear any previous match (like *.bz2, when pattern is *.tar.bz2)
             replace = true;
         }
@@ -44,7 +44,7 @@ void QMimeGlobMatchResult::addMatch(const QString &mimeType, int weight, const Q
     if (replace) {
         m_matchingMimeTypes.clear();
         // remember the new "longer" length
-        m_matchingPatternLength = pattern.length();
+        m_matchingPatternLength = pattern.size();
         m_weight = weight;
     }
     if (!m_matchingMimeTypes.contains(mimeType)) {
@@ -59,7 +59,7 @@ void QMimeGlobMatchResult::addMatch(const QString &mimeType, int weight, const Q
 
 QMimeGlobPattern::PatternType QMimeGlobPattern::detectPatternType(const QString &pattern) const
 {
-    const int patternLength = pattern.length();
+    const int patternLength = pattern.size();
     if (!patternLength)
         return OtherPattern;
 
@@ -108,10 +108,10 @@ bool QMimeGlobPattern::matchFileName(const QString &inputFileName) const
     const QString fileName = m_caseSensitivity == Qt::CaseInsensitive
             ? inputFileName.toLower() : inputFileName;
 
-    const int patternLength = m_pattern.length();
+    const int patternLength = m_pattern.size();
     if (!patternLength)
         return false;
-    const int fileNameLength = fileName.length();
+    const int fileNameLength = fileName.size();
 
     switch (m_patternType) {
     case SuffixPattern: {
@@ -166,7 +166,7 @@ static bool isSimplePattern(const QString &pattern)
 {
    // starts with "*.", has no other '*'
    return pattern.lastIndexOf(u'*') == 0
-      && pattern.length() > 1
+      && pattern.size() > 1
       && pattern.at(1) == u'.' // (other dots are OK, like *.tar.bz2)
       // and contains no other special character
       && !pattern.contains(u'?')
@@ -229,7 +229,7 @@ void QMimeGlobPatternList::match(QMimeGlobMatchResult &result,
         const QMimeGlobPattern &glob = *it;
         if (glob.matchFileName(fileName)) {
             const QString pattern = glob.pattern();
-            const int suffixLen = isSimplePattern(pattern) ? pattern.length() - 2 : 0;
+            const int suffixLen = isSimplePattern(pattern) ? pattern.size() - 2 : 0;
             result.addMatch(glob.mimeType(), glob.weight(), pattern, suffixLen);
         }
     }
@@ -244,7 +244,7 @@ void QMimeAllGlobPatterns::matchingGlobs(const QString &fileName, QMimeGlobMatch
     // (which is most of them, so this optimization is definitely worth it)
     const int lastDot = fileName.lastIndexOf(u'.');
     if (lastDot != -1) { // if no '.', skip the extension lookup
-        const int ext_len = fileName.length() - lastDot - 1;
+        const int ext_len = fileName.size() - lastDot - 1;
         const QString simpleExtension = fileName.right(ext_len).toLower();
         // (toLower because fast patterns are always case-insensitive and saved as lowercase)
 
diff --git a/src/corelib/mimetypes/qmimeprovider.cpp b/src/corelib/mimetypes/qmimeprovider.cpp
index cbb1ccd527..2642e5dad5 100644
--- a/src/corelib/mimetypes/qmimeprovider.cpp
+++ b/src/corelib/mimetypes/qmimeprovider.cpp
@@ -219,9 +219,9 @@ void QMimeBinaryProvider::addFileNameMatches(const QString &fileName, QMimeGlobM
         const int reverseSuffixTreeOffset = m_cacheFile->getUint32(PosReverseSuffixTreeOffset);
         const int numRoots = m_cacheFile->getUint32(reverseSuffixTreeOffset);
         const int firstRootOffset = m_cacheFile->getUint32(reverseSuffixTreeOffset + 4);
-        matchSuffixTree(result, m_cacheFile, numRoots, firstRootOffset, lowerFileName, lowerFileName.length() - 1, false);
+        matchSuffixTree(result, m_cacheFile, numRoots, firstRootOffset, lowerFileName, lowerFileName.size() - 1, false);
         if (result.m_matchingMimeTypes.isEmpty())
-            matchSuffixTree(result, m_cacheFile, numRoots, firstRootOffset, fileName, fileName.length() - 1, true);
+            matchSuffixTree(result, m_cacheFile, numRoots, firstRootOffset, fileName, fileName.size() - 1, true);
     }
     // Check complex globs (e.g. "callgrind.out[0-9]*" or "README*")
     if (result.m_matchingMimeTypes.isEmpty())
@@ -448,7 +448,7 @@ void QMimeBinaryProvider::addAllMimeTypes(QList<QMimeType> &result)
 {
     loadMimeTypeList();
     if (result.isEmpty()) {
-        result.reserve(m_mimetypeNames.count());
+        result.reserve(m_mimetypeNames.size());
         for (const QString &name : qAsConst(m_mimetypeNames))
             result.append(mimeTypeForNameUnchecked(name));
     } else {
diff --git a/src/corelib/mimetypes/qmimetype.cpp b/src/corelib/mimetypes/qmimetype.cpp
index c578f3cad0..16b6d460eb 100644
--- a/src/corelib/mimetypes/qmimetype.cpp
+++ b/src/corelib/mimetypes/qmimetype.cpp
@@ -413,7 +413,7 @@ QStringList QMimeType::suffixes() const
     for (const QString &pattern : qAsConst(d->globPatterns)) {
         // Not a simple suffix if it looks like: README or *. or *.* or *.JP*G or *.JP?
         if (pattern.startsWith("*."_L1) &&
-            pattern.length() > 2 &&
+            pattern.size() > 2 &&
             pattern.indexOf(u'*', 2) < 0 && pattern.indexOf(u'?', 2) < 0) {
             const QString suffix = pattern.mid(2);
             result.append(suffix);
diff --git a/src/corelib/serialization/qcborstreamreader.cpp b/src/corelib/serialization/qcborstreamreader.cpp
index 65edd3a941..a45158bcb0 100644
--- a/src/corelib/serialization/qcborstreamreader.cpp
+++ b/src/corelib/serialization/qcborstreamreader.cpp
@@ -1309,7 +1309,7 @@ QCborStreamReader::StringResult<QString> QCborStreamReader::_readString_helper()
     if (r.status == Error) {
         result.data.clear();
     } else {
-        Q_ASSERT(r.data == result.data.length());
+        Q_ASSERT(r.data == result.data.size());
         if (r.status == EndOfString && lastError() == QCborError::NoError)
             preparse();
     }
@@ -1341,7 +1341,7 @@ QCborStreamReader::StringResult<QByteArray> QCborStreamReader::_readByteArray_he
     if (r.status == Error) {
         result.data.clear();
     } else {
-        Q_ASSERT(r.data == result.data.length());
+        Q_ASSERT(r.data == result.data.size());
         if (r.status == EndOfString && lastError() == QCborError::NoError)
             preparse();
     }
diff --git a/src/corelib/serialization/qjsonarray.cpp b/src/corelib/serialization/qjsonarray.cpp
index e9914e3564..01899aaf95 100644
--- a/src/corelib/serialization/qjsonarray.cpp
+++ b/src/corelib/serialization/qjsonarray.cpp
@@ -330,7 +330,7 @@ void QJsonArray::append(const QJsonValue &value)
  */
 void QJsonArray::removeAt(qsizetype i)
 {
-    if (!a || i < 0 || i >= a->elements.length())
+    if (!a || i < 0 || i >= a->elements.size())
         return;
     detach();
     a->removeAt(i);
@@ -366,7 +366,7 @@ void QJsonArray::removeAt(qsizetype i)
  */
 QJsonValue QJsonArray::takeAt(qsizetype i)
 {
-    if (!a || i < 0 || i >= a->elements.length())
+    if (!a || i < 0 || i >= a->elements.size())
         return QJsonValue(QJsonValue::Undefined);
 
     detach();
@@ -385,11 +385,11 @@ QJsonValue QJsonArray::takeAt(qsizetype i)
 void QJsonArray::insert(qsizetype i, const QJsonValue &value)
 {
     if (a)
-        detach(a->elements.length() + 1);
+        detach(a->elements.size() + 1);
     else
         a = new QCborContainerPrivate;
 
-    Q_ASSERT (i >= 0 && i <= a->elements.length());
+    Q_ASSERT (i >= 0 && i <= a->elements.size());
     a->insertAt(i, value.type() == QJsonValue::Undefined ? QCborValue(nullptr)
                                                          : QCborValue::fromJsonValue(value));
 }
@@ -420,7 +420,7 @@ void QJsonArray::insert(qsizetype i, const QJsonValue &value)
  */
 void QJsonArray::replace(qsizetype i, const QJsonValue &value)
 {
-    Q_ASSERT (a && i >= 0 && i < a->elements.length());
+    Q_ASSERT (a && i >= 0 && i < a->elements.size());
     detach();
     a->replaceAt(i, QCborValue::fromJsonValue(value));
 }
@@ -454,7 +454,7 @@ bool QJsonArray::contains(const QJsonValue &value) const
  */
 QJsonValueRef QJsonArray::operator [](qsizetype i)
 {
-    Q_ASSERT(a && i >= 0 && i < a->elements.length());
+    Q_ASSERT(a && i >= 0 && i < a->elements.size());
     return QJsonValueRef(this, i);
 }
 
@@ -477,13 +477,13 @@ bool QJsonArray::operator==(const QJsonArray &other) const
         return true;
 
     if (!a)
-        return !other.a->elements.length();
+        return !other.a->elements.size();
     if (!other.a)
-        return !a->elements.length();
-    if (a->elements.length() != other.a->elements.length())
+        return !a->elements.size();
+    if (a->elements.size() != other.a->elements.size())
         return false;
 
-    for (qsizetype i = 0; i < a->elements.length(); ++i) {
+    for (qsizetype i = 0; i < a->elements.size(); ++i) {
         if (a->valueAt(i) != other.a->valueAt(i))
             return false;
     }
diff --git a/src/corelib/serialization/qjsondocument.cpp b/src/corelib/serialization/qjsondocument.cpp
index 814033610f..a77aab3895 100644
--- a/src/corelib/serialization/qjsondocument.cpp
+++ b/src/corelib/serialization/qjsondocument.cpp
@@ -280,7 +280,7 @@ QByteArray QJsonDocument::toJson(JsonFormat format) const
  */
 QJsonDocument QJsonDocument::fromJson(const QByteArray &json, QJsonParseError *error)
 {
-    QJsonPrivate::Parser parser(json.constData(), json.length());
+    QJsonPrivate::Parser parser(json.constData(), json.size());
     QJsonDocument result;
     const QCborValue val = parser.parse(error);
     if (val.isArray() || val.isMap()) {
diff --git a/src/corelib/serialization/qjsonobject.cpp b/src/corelib/serialization/qjsonobject.cpp
index 1fdcbef829..ab482876af 100644
--- a/src/corelib/serialization/qjsonobject.cpp
+++ b/src/corelib/serialization/qjsonobject.cpp
@@ -228,8 +228,8 @@ QStringList QJsonObject::keys() const
 {
     QStringList keys;
     if (o) {
-        keys.reserve(o->elements.length() / 2);
-        for (qsizetype i = 0, end = o->elements.length(); i < end; i += 2)
+        keys.reserve(o->elements.size() / 2);
+        for (qsizetype i = 0, end = o->elements.size(); i < end; i += 2)
             keys.append(o->stringAt(i));
     }
     return keys;
@@ -240,7 +240,7 @@ QStringList QJsonObject::keys() const
  */
 qsizetype QJsonObject::size() const
 {
-    return o ? o->elements.length() / 2 : 0;
+    return o ? o->elements.size() / 2 : 0;
 }
 
 /*!
@@ -392,7 +392,7 @@ QJsonValueRef QJsonObject::atImpl(T key)
     bool keyExists = false;
     auto index = indexOf(o, key, &keyExists);
     if (!keyExists) {
-        detach(o->elements.length() / 2 + 1);
+        detach(o->elements.size() / 2 + 1);
         o->insertAt(index, key);
         o->insertAt(index + 1, QCborValue::fromJsonValue(QJsonValue()));
     }
@@ -458,7 +458,7 @@ template <typename T>
 QJsonObject::iterator QJsonObject::insertAt(qsizetype pos, T key, const QJsonValue &value, bool keyExists)
 {
     if (o)
-        detach(o->elements.length() / 2 + (keyExists ? 0 : 1));
+        detach(o->elements.size() / 2 + (keyExists ? 0 : 1));
     else
         o = new QCborContainerPrivate;
 
@@ -619,13 +619,13 @@ bool QJsonObject::operator==(const QJsonObject &other) const
         return true;
 
     if (!o)
-        return !other.o->elements.length();
+        return !other.o->elements.size();
     if (!other.o)
-        return !o->elements.length();
-    if (o->elements.length() != other.o->elements.length())
+        return !o->elements.size();
+    if (o->elements.size() != other.o->elements.size())
         return false;
 
-    for (qsizetype i = 0, end = o->elements.length(); i < end; ++i) {
+    for (qsizetype i = 0, end = o->elements.size(); i < end; ++i) {
         if (o->valueAt(i) != other.o->valueAt(i))
             return false;
     }
@@ -1352,7 +1352,7 @@ bool QJsonObject::detach(qsizetype reserve)
 {
     if (!o)
         return true;
-    o = QCborContainerPrivate::detach(o.data(), reserve ? reserve * 2 : o->elements.length());
+    o = QCborContainerPrivate::detach(o.data(), reserve ? reserve * 2 : o->elements.size());
     return o;
 }
 
@@ -1362,7 +1362,7 @@ bool QJsonObject::detach(qsizetype reserve)
  */
 QString QJsonObject::keyAt(qsizetype i) const
 {
-    Q_ASSERT(o && i >= 0 && i * 2 < o->elements.length());
+    Q_ASSERT(o && i >= 0 && i * 2 < o->elements.size());
     return o->stringAt(i * 2);
 }
 
@@ -1371,7 +1371,7 @@ QString QJsonObject::keyAt(qsizetype i) const
  */
 QJsonValue QJsonObject::valueAt(qsizetype i) const
 {
-    if (!o || i < 0 || 2 * i + 1 >= o->elements.length())
+    if (!o || i < 0 || 2 * i + 1 >= o->elements.size())
         return QJsonValue(QJsonValue::Undefined);
     return QJsonPrivate::Value::fromTrustedCbor(o->valueAt(2 * i + 1));
 }
@@ -1381,7 +1381,7 @@ QJsonValue QJsonObject::valueAt(qsizetype i) const
  */
 void QJsonObject::setValueAt(qsizetype i, const QJsonValue &val)
 {
-    Q_ASSERT(o && i >= 0 && 2 * i + 1 < o->elements.length());
+    Q_ASSERT(o && i >= 0 && 2 * i + 1 < o->elements.size());
     detach();
     if (val.isUndefined()) {
         o->removeAt(2 * i + 1);
diff --git a/src/corelib/serialization/qjsonparser.cpp b/src/corelib/serialization/qjsonparser.cpp
index 294a65fa86..acc2bc383f 100644
--- a/src/corelib/serialization/qjsonparser.cpp
+++ b/src/corelib/serialization/qjsonparser.cpp
@@ -552,7 +552,7 @@ bool Parser::parseArray()
         }
     }
 
-    DEBUG << "size =" << (container ? container->elements.length() : 0);
+    DEBUG << "size =" << (container ? container->elements.size() : 0);
     END;
 
     --nestingLevel;
diff --git a/src/corelib/serialization/qjsonwriter.cpp b/src/corelib/serialization/qjsonwriter.cpp
index f4ec110684..b0e6ef1d0c 100644
--- a/src/corelib/serialization/qjsonwriter.cpp
+++ b/src/corelib/serialization/qjsonwriter.cpp
@@ -25,10 +25,10 @@ static inline uchar hexdig(uint u)
 static QByteArray escapedString(const QString &s)
 {
     // give it a minimum size to ensure the resize() below always adds enough space
-    QByteArray ba(qMax(s.length(), 16), Qt::Uninitialized);
+    QByteArray ba(qMax(s.size(), 16), Qt::Uninitialized);
 
     uchar *cursor = reinterpret_cast<uchar *>(const_cast<char *>(ba.constData()));
-    const uchar *ba_end = cursor + ba.length();
+    const uchar *ba_end = cursor + ba.size();
     const char16_t *src = reinterpret_cast<const char16_t *>(s.constBegin());
     const char16_t *const end = reinterpret_cast<const char16_t *>(s.constEnd());
 
@@ -38,7 +38,7 @@ static QByteArray escapedString(const QString &s)
             int pos = cursor - (const uchar *)ba.constData();
             ba.resize(ba.size()*2);
             cursor = (uchar *)ba.data() + pos;
-            ba_end = (const uchar *)ba.constData() + ba.length();
+            ba_end = (const uchar *)ba.constData() + ba.size();
         }
 
         char16_t u = *src++;
diff --git a/src/corelib/serialization/qtextstream.cpp b/src/corelib/serialization/qtextstream.cpp
index ca2f0684d4..2a2536aeee 100644
--- a/src/corelib/serialization/qtextstream.cpp
+++ b/src/corelib/serialization/qtextstream.cpp
@@ -2497,7 +2497,7 @@ QTextStream &QTextStream::operator<<(const QByteArray &array)
 {
     Q_D(QTextStream);
     CHECK_VALID_STREAM(*this);
-    d->putString(QString::fromUtf8(array.constData(), array.length()));
+    d->putString(QString::fromUtf8(array.constData(), array.size()));
     return *this;
 }
 
diff --git a/src/corelib/serialization/qxmlstream.cpp b/src/corelib/serialization/qxmlstream.cpp
index f6671ea780..80eed02b11 100644
--- a/src/corelib/serialization/qxmlstream.cpp
+++ b/src/corelib/serialization/qxmlstream.cpp
@@ -3028,7 +3028,7 @@ void QXmlStreamWriterPrivate::indent(int level)
 {
     write("\n");
     for (int i = level; i > 0; --i)
-        write(autoFormattingIndent.constData(), autoFormattingIndent.length());
+        write(autoFormattingIndent.constData(), autoFormattingIndent.size());
 }
 
 
diff --git a/src/corelib/text/qbytedata_p.h b/src/corelib/text/qbytedata_p.h
index 2f4197d775..fcbf82d6ce 100644
--- a/src/corelib/text/qbytedata_p.h
+++ b/src/corelib/text/qbytedata_p.h
@@ -241,7 +241,7 @@ public:
     // the number of QByteArrays
     qsizetype bufferCount() const
     {
-        return buffers.length();
+        return buffers.size();
     }
 
     inline bool isEmpty() const
@@ -267,12 +267,12 @@ public:
 
     inline bool canReadLine() const {
         qsizetype i = 0;
-        if (i < buffers.length()) {
+        if (i < buffers.size()) {
             if (buffers.at(i).indexOf('\n', firstPos) != -1)
                 return true;
             ++i;
 
-            for (; i < buffers.length(); i++)
+            for (; i < buffers.size(); i++)
                 if (buffers.at(i).contains('\n'))
                     return true;
         }
diff --git a/src/corelib/text/qchar.cpp b/src/corelib/text/qchar.cpp
index d5441817d9..f4c5ab969a 100644
--- a/src/corelib/text/qchar.cpp
+++ b/src/corelib/text/qchar.cpp
@@ -1815,7 +1815,7 @@ static void decomposeHelper(QString *str, bool canonical, QChar::UnicodeVersion
     QString &s = *str;
 
     const unsigned short *utf16 = reinterpret_cast<unsigned short *>(s.data());
-    const unsigned short *uc = utf16 + s.length();
+    const unsigned short *uc = utf16 + s.size();
     while (uc != utf16 + from) {
         char32_t ucs4 = *(--uc);
         if (QChar(ucs4).isLowSurrogate() && uc != utf16) {
@@ -1910,7 +1910,7 @@ static void composeHelper(QString *str, QChar::UnicodeVersion version, qsizetype
 {
     QString &s = *str;
 
-    if (from < 0 || s.length() - from < 2)
+    if (from < 0 || s.size() - from < 2)
         return;
 
     char32_t stcode = 0; // starter code point
@@ -1919,10 +1919,10 @@ static void composeHelper(QString *str, QChar::UnicodeVersion version, qsizetype
     int lastCombining = 255; // to prevent combining > lastCombining
 
     qsizetype pos = from;
-    while (pos < s.length()) {
+    while (pos < s.size()) {
         qsizetype i = pos;
         char32_t uc = s.at(pos).unicode();
-        if (QChar(uc).isHighSurrogate() && pos < s.length()-1) {
+        if (QChar(uc).isHighSurrogate() && pos < s.size()-1) {
             ushort low = s.at(pos+1).unicode();
             if (QChar(low).isLowSurrogate()) {
                 uc = QChar::surrogateToUcs4(uc, low);
@@ -1969,7 +1969,7 @@ static void composeHelper(QString *str, QChar::UnicodeVersion version, qsizetype
 static void canonicalOrderHelper(QString *str, QChar::UnicodeVersion version, qsizetype from)
 {
     QString &s = *str;
-    const qsizetype l = s.length()-1;
+    const qsizetype l = s.size()-1;
 
     char32_t u1, u2;
     char16_t c1, c2;
diff --git a/src/corelib/text/qlocale.cpp b/src/corelib/text/qlocale.cpp
index ba97d8cbb4..585471975c 100644
--- a/src/corelib/text/qlocale.cpp
+++ b/src/corelib/text/qlocale.cpp
@@ -3745,11 +3745,11 @@ QString QLocaleData::decimalForm(QString &&digits, int decpt, int precision,
             digits.append(zero);
         break;
     case PMChopTrailingZeros:
-        Q_ASSERT(digits.length() / digitWidth <= qMax(decpt, 1) || !digits.endsWith(zero));
+        Q_ASSERT(digits.size() / digitWidth <= qMax(decpt, 1) || !digits.endsWith(zero));
         break;
     }
 
-    if (mustMarkDecimal || decpt < digits.length() / digitWidth)
+    if (mustMarkDecimal || decpt < digits.size() / digitWidth)
         digits.insert(decpt * digitWidth, decimalPoint());
 
     if (groupDigits) {
@@ -3787,11 +3787,11 @@ QString QLocaleData::exponentForm(QString &&digits, int decpt, int precision,
             digits.append(zero);
         break;
     case PMChopTrailingZeros:
-        Q_ASSERT(digits.length() / digitWidth <= 1 || !digits.endsWith(zero));
+        Q_ASSERT(digits.size() / digitWidth <= 1 || !digits.endsWith(zero));
         break;
     }
 
-    if (mustMarkDecimal || digits.length() > digitWidth)
+    if (mustMarkDecimal || digits.size() > digitWidth)
         digits.insert(digitWidth, decimalPoint());
 
     digits.append(exponentSeparator());
@@ -3840,7 +3840,7 @@ QString QLocaleData::applyIntegerFormatting(QString &&numStr, bool negative, int
 {
     const QString zero = base == 10 ? zeroDigit() : QStringLiteral("0");
     const auto digitWidth = zero.size();
-    const auto digitCount = numStr.length() / digitWidth;
+    const auto digitCount = numStr.size() / digitWidth;
 
     const auto basePrefix = [&] () -> QStringView {
         if (flags & ShowBase) {
diff --git a/src/corelib/text/qlocale_tools.cpp b/src/corelib/text/qlocale_tools.cpp
index e34cc1c947..ca6f954bed 100644
--- a/src/corelib/text/qlocale_tools.cpp
+++ b/src/corelib/text/qlocale_tools.cpp
@@ -687,7 +687,7 @@ static T dtoString(double d, QLocaleData::DoubleForm form, int precision, bool u
     bool negative = false;
     int length = 0;
     int decpt = 0;
-    qt_doubleToAscii(d, form, precision, buffer.data(), buffer.length(), negative, length, decpt);
+    qt_doubleToAscii(d, form, precision, buffer.data(), buffer.size(), negative, length, decpt);
     QLatin1StringView view(buffer.data(), length);
     const bool succinct = form == QLocaleData::DFSignificantDigits;
     qsizetype total = (negative ? 1 : 0) + length;
diff --git a/src/corelib/text/qregularexpression.cpp b/src/corelib/text/qregularexpression.cpp
index 0aa9087727..8b3cf63dd2 100644
--- a/src/corelib/text/qregularexpression.cpp
+++ b/src/corelib/text/qregularexpression.cpp
@@ -894,7 +894,7 @@ void QRegularExpressionPrivate::compilePattern()
 
     PCRE2_SIZE patternErrorOffset;
     compiledPattern = pcre2_compile_16(reinterpret_cast<PCRE2_SPTR16>(pattern.constData()),
-                                       pattern.length(),
+                                       pattern.size(),
                                        options,
                                        &errorCode,
                                        &patternErrorOffset,
@@ -1540,10 +1540,10 @@ QString QRegularExpression::errorString() const
         QString errorString;
         int errorStringLength;
         do {
-            errorString.resize(errorString.length() + 64);
+            errorString.resize(errorString.size() + 64);
             errorStringLength = pcre2_get_error_message_16(d->errorCode,
                                                            reinterpret_cast<ushort *>(errorString.data()),
-                                                           errorString.length());
+                                                           errorString.size());
         } while (errorStringLength < 0);
         errorString.resize(errorStringLength);
 
diff --git a/src/corelib/text/qstring.cpp b/src/corelib/text/qstring.cpp
index 732b797a9b..4df29ab52f 100644
--- a/src/corelib/text/qstring.cpp
+++ b/src/corelib/text/qstring.cpp
@@ -3444,7 +3444,7 @@ QString &QString::remove(QChar ch, Qt::CaseSensitivity cs)
 */
 QString &QString::replace(qsizetype pos, qsizetype len, const QString &after)
 {
-    return replace(pos, len, after.constData(), after.length());
+    return replace(pos, len, after.constData(), after.size());
 }
 
 /*!
@@ -4164,7 +4164,7 @@ QString &QString::replace(QChar c, QLatin1StringView after, Qt::CaseSensitivity
 */
 qsizetype QString::indexOf(const QString &str, qsizetype from, Qt::CaseSensitivity cs) const
 {
-    return QtPrivate::findString(QStringView(unicode(), length()), from, QStringView(str.unicode(), str.length()), cs);
+    return QtPrivate::findString(QStringView(unicode(), length()), from, QStringView(str.unicode(), str.size()), cs);
 }
 
 /*!
@@ -4418,7 +4418,7 @@ QString &QString::replace(const QRegularExpression &re, const QString &after)
     // 1. build the backreferences list, holding where the backreferences
     // are in the replacement string
     QList<QStringCapture> backReferences;
-    const qsizetype al = after.length();
+    const qsizetype al = after.size();
     const QChar *ac = after.unicode();
 
     for (qsizetype i = 0; i < al - 1; i++) {
@@ -6422,7 +6422,7 @@ int QLatin1StringView::compare_helper(const QChar *data1, qsizetype length1, QLa
 */
 int QString::localeAwareCompare(const QString &other) const
 {
-    return localeAwareCompare_helper(constData(), length(), other.constData(), other.length());
+    return localeAwareCompare_helper(constData(), length(), other.constData(), other.size());
 }
 
 /*!
@@ -7078,27 +7078,27 @@ QString QString::vasprintf(const char *cformat, va_list ap)
                 switch (length_mod) {
                     case lm_hh: {
                         signed char *n = va_arg(ap, signed char*);
-                        *n = result.length();
+                        *n = result.size();
                         break;
                     }
                     case lm_h: {
                         short int *n = va_arg(ap, short int*);
-                        *n = result.length();
+                        *n = result.size();
                             break;
                     }
                     case lm_l: {
                         long int *n = va_arg(ap, long int*);
-                        *n = result.length();
+                        *n = result.size();
                         break;
                     }
                     case lm_ll: {
                         qint64 *n = va_arg(ap, qint64*);
-                        *n = result.length();
+                        *n = result.size();
                         break;
                     }
                     default: {
                         int *n = va_arg(ap, int*);
-                        *n = result.length();
+                        *n = result.size();
                         break;
                     }
                 }
@@ -7928,7 +7928,7 @@ void qt_string_normalize(QString *data, QString::NormalizationForm mode, QChar::
                     char16_t ucs4Low = QChar::lowSurrogate(n.ucs4);
                     char16_t oldHigh = QChar::highSurrogate(n.old_mapping);
                     char16_t oldLow = QChar::lowSurrogate(n.old_mapping);
-                    while (pos < s.length() - 1) {
+                    while (pos < s.size() - 1) {
                         if (s.at(pos).unicode() == ucs4High && s.at(pos + 1).unicode() == ucs4Low) {
                             if (!d)
                                 d = data->data();
@@ -7938,7 +7938,7 @@ void qt_string_normalize(QString *data, QString::NormalizationForm mode, QChar::
                         ++pos;
                     }
                 } else {
-                    while (pos < s.length()) {
+                    while (pos < s.size()) {
                         if (s.at(pos).unicode() == n.ucs4) {
                             if (!d)
                                 d = data->data();
@@ -8381,7 +8381,7 @@ QString QString::arg(qlonglong a, int fieldWidth, int base, QChar fillChar) cons
     if (d.occurrences > d.locale_occurrences) {
         arg = QLocaleData::c()->longLongToString(a, -1, base, fieldWidth, flags);
         Q_ASSERT(fillChar != u'0' || !qIsFinite(a)
-                 || fieldWidth <= arg.length());
+                 || fieldWidth <= arg.size());
     }
 
     QString localeArg;
@@ -8391,7 +8391,7 @@ QString QString::arg(qlonglong a, int fieldWidth, int base, QChar fillChar) cons
             flags |= QLocaleData::GroupDigits;
         localeArg = locale.d->m_data->longLongToString(a, -1, base, fieldWidth, flags);
         Q_ASSERT(fillChar != u'0' || !qIsFinite(a)
-                 || fieldWidth <= localeArg.length());
+                 || fieldWidth <= localeArg.size());
     }
 
     return replaceArgEscapes(*this, d, fieldWidth, arg, localeArg, fillChar);
@@ -8429,7 +8429,7 @@ QString QString::arg(qulonglong a, int fieldWidth, int base, QChar fillChar) con
     if (d.occurrences > d.locale_occurrences) {
         arg = QLocaleData::c()->unsLongLongToString(a, -1, base, fieldWidth, flags);
         Q_ASSERT(fillChar != u'0' || !qIsFinite(a)
-                 || fieldWidth <= arg.length());
+                 || fieldWidth <= arg.size());
     }
 
     QString localeArg;
@@ -8439,7 +8439,7 @@ QString QString::arg(qulonglong a, int fieldWidth, int base, QChar fillChar) con
             flags |= QLocaleData::GroupDigits;
         localeArg = locale.d->m_data->unsLongLongToString(a, -1, base, fieldWidth, flags);
         Q_ASSERT(fillChar != u'0' || !qIsFinite(a)
-                 || fieldWidth <= localeArg.length());
+                 || fieldWidth <= localeArg.size());
     }
 
     return replaceArgEscapes(*this, d, fieldWidth, arg, localeArg, fillChar);
@@ -8551,7 +8551,7 @@ QString QString::arg(double a, int fieldWidth, char format, int precision, QChar
         arg = QLocaleData::c()->doubleToString(a, precision, form, fieldWidth,
                                                flags | QLocaleData::ZeroPadExponent);
         Q_ASSERT(fillChar != u'0' || !qIsFinite(a)
-                 || fieldWidth <= arg.length());
+                 || fieldWidth <= arg.size());
     }
 
     QString localeArg;
@@ -8567,7 +8567,7 @@ QString QString::arg(double a, int fieldWidth, char format, int precision, QChar
             flags |= QLocaleData::AddTrailingZeroes;
         localeArg = locale.d->m_data->doubleToString(a, precision, form, fieldWidth, flags);
         Q_ASSERT(fillChar != u'0' || !qIsFinite(a)
-                 || fieldWidth <= localeArg.length());
+                 || fieldWidth <= localeArg.size());
     }
 
     return replaceArgEscapes(*this, d, fieldWidth, arg, localeArg, fillChar);
@@ -10320,10 +10320,10 @@ QDataStream &operator<<(QDataStream &out, const QString &str)
         if (!str.isNull() || out.version() < 3) {
             if ((out.byteOrder() == QDataStream::BigEndian) == (QSysInfo::ByteOrder == QSysInfo::BigEndian)) {
                 out.writeBytes(reinterpret_cast<const char *>(str.unicode()),
-                               static_cast<uint>(sizeof(QChar) * str.length()));
+                               static_cast<uint>(sizeof(QChar) * str.size()));
             } else {
-                QVarLengthArray<char16_t> buffer(str.length());
-                qbswap<sizeof(char16_t)>(str.constData(), str.length(), buffer.data());
+                QVarLengthArray<char16_t> buffer(str.size());
+                qbswap<sizeof(char16_t)>(str.constData(), str.size(), buffer.data());
                 out.writeBytes(reinterpret_cast<const char *>(buffer.data()),
                                static_cast<uint>(sizeof(char16_t) * buffer.size()));
             }
diff --git a/src/corelib/text/qstring.h b/src/corelib/text/qstring.h
index 697233e443..512fa489f9 100644
--- a/src/corelib/text/qstring.h
+++ b/src/corelib/text/qstring.h
@@ -678,7 +678,7 @@ public:
 
     QString &insert(qsizetype i, QChar c);
     QString &insert(qsizetype i, const QChar *uc, qsizetype len);
-    inline QString &insert(qsizetype i, const QString &s) { return insert(i, s.constData(), s.length()); }
+    inline QString &insert(qsizetype i, const QString &s) { return insert(i, s.constData(), s.size()); }
     inline QString &insert(qsizetype i, QStringView v) { return insert(i, v.data(), v.length()); }
     QString &insert(qsizetype i, QLatin1StringView s);
 
diff --git a/src/corelib/text/qstringconverter.cpp b/src/corelib/text/qstringconverter.cpp
index 443dc8fce9..043be6f474 100644
--- a/src/corelib/text/qstringconverter.cpp
+++ b/src/corelib/text/qstringconverter.cpp
@@ -877,7 +877,7 @@ QByteArray QUtf16::convertFromUnicode(QStringView in, QStringConverter::State *s
 
     QByteArray d(length, Qt::Uninitialized);
     char *end = convertFromUnicode(d.data(), in, state, endian);
-    Q_ASSERT(end - d.constData() == d.length());
+    Q_ASSERT(end - d.constData() == d.size());
     Q_UNUSED(end);
     return d;
 }
@@ -1491,15 +1491,15 @@ static char *toLatin1(char *out, QStringView in, QStringConverter::State *state)
 static QChar *fromLocal8Bit(QChar *out, QByteArrayView in, QStringConverter::State *state)
 {
     QString s = QLocal8Bit::convertToUnicode(in, state);
-    memcpy(out, s.constData(), s.length()*sizeof(QChar));
-    return out + s.length();
+    memcpy(out, s.constData(), s.size()*sizeof(QChar));
+    return out + s.size();
 }
 
 static char *toLocal8Bit(char *out, QStringView in, QStringConverter::State *state)
 {
     QByteArray s = QLocal8Bit::convertFromUnicode(in, state);
-    memcpy(out, s.constData(), s.length());
-    return out + s.length();
+    memcpy(out, s.constData(), s.size());
+    return out + s.size();
 }
 
 
diff --git a/src/corelib/text/qstringlist.h b/src/corelib/text/qstringlist.h
index 079f156479..31e4cf6dc9 100644
--- a/src/corelib/text/qstringlist.h
+++ b/src/corelib/text/qstringlist.h
@@ -87,7 +87,7 @@ public:
     }
 
     inline QString join(const QString &sep) const
-    { return QtPrivate::QStringList_join(self(), sep.constData(), sep.length()); }
+    { return QtPrivate::QStringList_join(self(), sep.constData(), sep.size()); }
     inline QStringList filter(const QString &str, Qt::CaseSensitivity cs = Qt::CaseSensitive) const
     { return QtPrivate::QStringList_filter(self(), str, cs); }
     inline QStringList &replaceInStrings(const QString &before, const QString &after, Qt::CaseSensitivity cs = Qt::CaseSensitive)
diff --git a/src/corelib/thread/qfutureinterface.cpp b/src/corelib/thread/qfutureinterface.cpp
index b62ceaf91d..eedfd7ceeb 100644
--- a/src/corelib/thread/qfutureinterface.cpp
+++ b/src/corelib/thread/qfutureinterface.cpp
@@ -726,7 +726,7 @@ void QFutureInterfaceBasePrivate::sendCallOut(const QFutureCallOutEvent &callOut
     if (outputConnections.isEmpty())
         return;
 
-    for (int i = 0; i < outputConnections.count(); ++i)
+    for (int i = 0; i < outputConnections.size(); ++i)
         outputConnections.at(i)->postCallOutEvent(callOutEvent);
 }
 
@@ -736,7 +736,7 @@ void QFutureInterfaceBasePrivate::sendCallOuts(const QFutureCallOutEvent &callOu
     if (outputConnections.isEmpty())
         return;
 
-    for (int i = 0; i < outputConnections.count(); ++i) {
+    for (int i = 0; i < outputConnections.size(); ++i) {
         QFutureCallOutInterface *interface = outputConnections.at(i);
         interface->postCallOutEvent(callOutEvent1);
         interface->postCallOutEvent(callOutEvent2);
diff --git a/src/corelib/thread/qfutureinterface.h b/src/corelib/thread/qfutureinterface.h
index eb251c7d14..418f19866d 100644
--- a/src/corelib/thread/qfutureinterface.h
+++ b/src/corelib/thread/qfutureinterface.h
@@ -347,7 +347,7 @@ inline bool QFutureInterface<T>::reportResults(const QList<T> &_results, int beg
     if (store.filterMode()) {
         this->reportResultsReady(resultCountBefore, store.count());
     } else {
-        this->reportResultsReady(insertIndex, insertIndex + _results.count());
+        this->reportResultsReady(insertIndex, insertIndex + _results.size());
     }
     return true;
 }
diff --git a/src/corelib/thread/qfuturesynchronizer.h b/src/corelib/thread/qfuturesynchronizer.h
index 8b85e20038..2cf2ca1b76 100644
--- a/src/corelib/thread/qfuturesynchronizer.h
+++ b/src/corelib/thread/qfuturesynchronizer.h
@@ -38,12 +38,12 @@ public:
     void waitForFinished()
     {
         if (m_cancelOnWait) {
-            for (int i = 0; i < m_futures.count(); ++i) {
+            for (int i = 0; i < m_futures.size(); ++i) {
                  m_futures[i].cancel();
             }
         }
 
-        for (int i = 0; i < m_futures.count(); ++i) {
+        for (int i = 0; i < m_futures.size(); ++i) {
              m_futures[i].waitForFinished();
          }
     }
diff --git a/src/corelib/thread/qthreadpool.cpp b/src/corelib/thread/qthreadpool.cpp
index b1078dab18..1c3b79033a 100644
--- a/src/corelib/thread/qthreadpool.cpp
+++ b/src/corelib/thread/qthreadpool.cpp
@@ -200,9 +200,9 @@ void QThreadPoolPrivate::enqueueTask(QRunnable *runnable, int priority)
 
 int QThreadPoolPrivate::activeThreadCount() const
 {
-    return (allThreads.count()
-            - expiredThreads.count()
-            - waitingThreads.count()
+    return (allThreads.size()
+            - expiredThreads.size()
+            - waitingThreads.size()
             + reservedThreads);
 }
 
diff --git a/src/corelib/thread/qthreadstorage.cpp b/src/corelib/thread/qthreadstorage.cpp
index 55a603e0e6..0386e47102 100644
--- a/src/corelib/thread/qthreadstorage.cpp
+++ b/src/corelib/thread/qthreadstorage.cpp
@@ -51,7 +51,7 @@ QThreadStorageData::QThreadStorageData(void (*func)(void *))
          no where to store it, and no way to actually call it.
          */
         QThreadData *data = QThreadData::current();
-        id = data->tls.count();
+        id = data->tls.size();
         DEBUG_MSG("QThreadStorageData: Allocated id %d, destructor %p cannot be stored", id, func);
         return;
     }
diff --git a/src/corelib/time/qdatetime.cpp b/src/corelib/time/qdatetime.cpp
index 689bc88c24..46a33d55c7 100644
--- a/src/corelib/time/qdatetime.cpp
+++ b/src/corelib/time/qdatetime.cpp
@@ -4998,7 +4998,7 @@ QDateTime QDateTime::fromString(QStringView string, Qt::DateFormat format)
 
         // Documented as "ddd MMM d HH:mm:ss yyyy" with optional offset-suffix;
         // and allow time either before or after year.
-        if (parts.count() < 5 || it != tokens.end())
+        if (parts.size() < 5 || it != tokens.end())
             return QDateTime();
 
         // Year and time can be in either order.
@@ -5027,7 +5027,7 @@ QDateTime QDateTime::fromString(QStringView string, Qt::DateFormat format)
         if (!time.isValid())
             return QDateTime();
 
-        if (parts.count() == 5)
+        if (parts.size() == 5)
             return QDateTime(date, time, Qt::LocalTime);
 
         QStringView tz = parts.at(5);
diff --git a/src/corelib/time/qtimezoneprivate.cpp b/src/corelib/time/qtimezoneprivate.cpp
index ab3a4e395d..53be1330dc 100644
--- a/src/corelib/time/qtimezoneprivate.cpp
+++ b/src/corelib/time/qtimezoneprivate.cpp
@@ -662,7 +662,7 @@ QByteArray QTimeZonePrivate::windowsIdToDefaultIanaId(const QByteArray &windowsI
                                                       QLocale::Territory territory)
 {
     const QList<QByteArray> list = windowsIdToIanaIds(windowsId, territory);
-    return list.count() > 0 ? list.first() : QByteArray();
+    return list.size() > 0 ? list.first() : QByteArray();
 }
 
 QList<QByteArray> QTimeZonePrivate::windowsIdToIanaIds(const QByteArray &windowsId)
diff --git a/src/corelib/time/qtimezoneprivate_tz.cpp b/src/corelib/time/qtimezoneprivate_tz.cpp
index 627a4a8165..1ee1360fa1 100644
--- a/src/corelib/time/qtimezoneprivate_tz.cpp
+++ b/src/corelib/time/qtimezoneprivate_tz.cpp
@@ -357,7 +357,7 @@ static QDate calculatePosixDate(const QByteArray &dateRule, int year)
     if (dateRule.at(0) == 'M') {
         // nth week in month format "Mmonth.week.dow"
         QList<QByteArray> dateParts = dateRule.split('.');
-        if (dateParts.count() > 2) {
+        if (dateParts.size() > 2) {
             int month = dateParts.at(0).mid(1).toInt(&ok);
             int week = ok ? dateParts.at(1).toInt(&ok) : 0;
             int dow = ok ? dateParts.at(2).toInt(&ok) : 0;
@@ -526,7 +526,7 @@ static auto validatePosixRule(const QByteArray &posixRule)
     // http://www.gnu.org/software/libc/manual/html_node/TZ-Variable.html
     // See also calculatePosixTransition()'s reference.
     const auto parts = posixRule.split(',');
-    const struct { bool isValid, hasDst; } fail{false, false}, good{true, parts.count() > 1};
+    const struct { bool isValid, hasDst; } fail{false, false}, good{true, parts.size() > 1};
     const QByteArray &zoneinfo = parts.at(0);
     if (zoneinfo.isEmpty())
         return fail;
@@ -548,13 +548,13 @@ static auto validatePosixRule(const QByteArray &posixRule)
         return fail;
 
     if (good.hasDst) {
-        if (parts.count() != 3 || parts.at(1).isEmpty() || parts.at(2).isEmpty())
+        if (parts.size() != 3 || parts.at(1).isEmpty() || parts.at(2).isEmpty())
             return fail;
         for (int i = 1; i < 3; ++i) {
             const auto tran = parts.at(i).split('/');
             if (!calculatePosixDate(tran.at(0), 1972).isValid())
                 return fail;
-            if (tran.count() > 1) {
+            if (tran.size() > 1) {
                 const auto time = tran.at(1);
                 if (parsePosixTime(time.begin(), time.end()) == INT_MIN)
                     return fail;
@@ -595,7 +595,7 @@ static QList<QTimeZonePrivate::Data> calculatePosixTransitions(const QByteArray
     }
 
     // If only the name part, or no DST specified, then no transitions
-    if (parts.count() == 1 || !dstZone.hasValidOffset()) {
+    if (parts.size() == 1 || !dstZone.hasValidOffset()) {
         QTimeZonePrivate::Data data;
         data.atMSecsSinceEpoch = lastTranMSecs;
         data.offsetFromUtc = stdZone.offset;
@@ -605,19 +605,19 @@ static QList<QTimeZonePrivate::Data> calculatePosixTransitions(const QByteArray
         result << data;
         return result;
     }
-    if (parts.count() < 3 || parts.at(1).isEmpty() || parts.at(2).isEmpty())
+    if (parts.size() < 3 || parts.at(1).isEmpty() || parts.at(2).isEmpty())
         return result; // Malformed.
 
     // Get the std to dst transition details
     const int twoOClock = 7200; // Default transition time, when none specified
     const auto dstParts = parts.at(1).split('/');
     const QByteArray dstDateRule = dstParts.at(0);
-    const int dstTime = dstParts.count() < 2 ? twoOClock : parsePosixTransitionTime(dstParts.at(1));
+    const int dstTime = dstParts.size() < 2 ? twoOClock : parsePosixTransitionTime(dstParts.at(1));
 
     // Get the dst to std transition details
     const auto stdParts = parts.at(2).split('/');
     const QByteArray stdDateRule = stdParts.at(0);
-    const int stdTime = stdParts.count() < 2 ? twoOClock : parsePosixTransitionTime(stdParts.at(1));
+    const int stdTime = stdParts.size() < 2 ? twoOClock : parsePosixTransitionTime(stdParts.at(1));
 
     if (dstDateRule.isEmpty() || stdDateRule.isEmpty() || dstTime == INT_MIN || stdTime == INT_MIN)
         return result; // Malformed.
@@ -834,7 +834,7 @@ QTzTimeZoneCacheEntry QTzTimeZoneCache::findEntry(const QByteArray &ianaId)
     }
 
     // Now for each transition time calculate and store our rule:
-    const int tranCount = tranList.count();;
+    const int tranCount = tranList.size();;
     ret.m_tranTimes.reserve(tranCount);
     // The DST offset when in effect: usually stable, usually an hour:
     int lastDstOff = 3600;
diff --git a/src/corelib/tools/qcommandlineparser.cpp b/src/corelib/tools/qcommandlineparser.cpp
index e771877265..9f890fa8be 100644
--- a/src/corelib/tools/qcommandlineparser.cpp
+++ b/src/corelib/tools/qcommandlineparser.cpp
@@ -691,7 +691,7 @@ bool QCommandLineParserPrivate::parse(const QStringList &args)
         if (forcePositional) {
             positionalArgumentList.append(argument);
         } else if (argument.startsWith(doubleDashString)) {
-            if (argument.length() > 2) {
+            if (argument.size() > 2) {
                 QString optionName = argument.mid(2).section(assignChar, 0, 0);
                 if (registerFoundOption(optionName)) {
                     if (!parseOptionValue(optionName, argument, &argumentIterator, args.end()))
@@ -1042,7 +1042,7 @@ static QString wrapText(const QString &names, int optionNameMaxWidth, const QStr
     int lastBreakable = -1;
     const int max = 79 - (indentation.size() + optionNameMaxWidth + 1);
     int x = 0;
-    const int len = description.length();
+    const int len = description.size();
 
     for (int i = 0; i < len; ++i) {
         ++x;
@@ -1116,7 +1116,7 @@ QString QCommandLineParserPrivate::helpText(bool includeQtOptions) const
         const QStringList optionNames = option.names();
         QString optionNamesString;
         for (const QString &optionName : optionNames) {
-            const int numDashes = optionName.length() == 1 ? 1 : 2;
+            const int numDashes = optionName.size() == 1 ? 1 : 2;
             optionNamesString += QLatin1StringView("--", numDashes) + optionName + ", "_L1;
         }
         if (!optionNames.isEmpty())
@@ -1125,7 +1125,7 @@ QString QCommandLineParserPrivate::helpText(bool includeQtOptions) const
         if (!valueName.isEmpty())
             optionNamesString += " <"_L1 + valueName + u'>';
         optionNameList.append(optionNamesString);
-        longestOptionNameString = qMax(longestOptionNameString, optionNamesString.length());
+        longestOptionNameString = qMax(longestOptionNameString, optionNamesString.size());
     }
     ++longestOptionNameString;
     const int optionNameMaxWidth = qMin(50, longestOptionNameString);
diff --git a/src/corelib/tools/qeasingcurve.cpp b/src/corelib/tools/qeasingcurve.cpp
index 9242a617ba..40041a9ff3 100644
--- a/src/corelib/tools/qeasingcurve.cpp
+++ b/src/corelib/tools/qeasingcurve.cpp
@@ -447,7 +447,7 @@ struct BezierEase : public QEasingCurveFunction
     {
         if (_bezierCurves.constLast() == QPointF(1.0, 1.0)) {
             _init = true;
-            _curveCount = _bezierCurves.count() / 3;
+            _curveCount = _bezierCurves.size() / 3;
 
             for (int i=0; i < _curveCount; i++) {
                 _intervals[i] = _bezierCurves.at(i * 3 + 2).x();
@@ -466,17 +466,17 @@ struct BezierEase : public QEasingCurveFunction
                     _curves[0].p3y = _bezierCurves.at(2).y();
 
                 } else if (i == (_curveCount - 1)) {
-                    _curves[i].p0x = _bezierCurves.at(_bezierCurves.count() - 4).x();
-                    _curves[i].p0y = _bezierCurves.at(_bezierCurves.count() - 4).y();
+                    _curves[i].p0x = _bezierCurves.at(_bezierCurves.size() - 4).x();
+                    _curves[i].p0y = _bezierCurves.at(_bezierCurves.size() - 4).y();
 
-                    _curves[i].p1x = _bezierCurves.at(_bezierCurves.count() - 3).x();
-                    _curves[i].p1y = _bezierCurves.at(_bezierCurves.count() - 3).y();
+                    _curves[i].p1x = _bezierCurves.at(_bezierCurves.size() - 3).x();
+                    _curves[i].p1y = _bezierCurves.at(_bezierCurves.size() - 3).y();
 
-                    _curves[i].p2x = _bezierCurves.at(_bezierCurves.count() - 2).x();
-                    _curves[i].p2y = _bezierCurves.at(_bezierCurves.count() - 2).y();
+                    _curves[i].p2x = _bezierCurves.at(_bezierCurves.size() - 2).x();
+                    _curves[i].p2y = _bezierCurves.at(_bezierCurves.size() - 2).y();
 
-                    _curves[i].p3x = _bezierCurves.at(_bezierCurves.count() - 1).x();
-                    _curves[i].p3y = _bezierCurves.at(_bezierCurves.count() - 1).y();
+                    _curves[i].p3x = _bezierCurves.at(_bezierCurves.size() - 1).x();
+                    _curves[i].p3y = _bezierCurves.at(_bezierCurves.size() - 1).y();
                 } else {
                     _curves[i].p0x = _bezierCurves.at(i * 3 - 1).x();
                     _curves[i].p0y = _bezierCurves.at(i * 3 - 1).y();
@@ -535,7 +535,7 @@ struct BezierEase : public QEasingCurveFunction
 
     qreal value(qreal x) override
     {
-        Q_ASSERT(_bezierCurves.count() % 3 == 0);
+        Q_ASSERT(_bezierCurves.size() % 3 == 0);
 
         if (_bezierCurves.isEmpty()) {
             return x;
@@ -869,7 +869,7 @@ struct TCBEase : public BezierEase
 
     qreal value(qreal x) override
     {
-        Q_ASSERT(_bezierCurves.count() % 3 == 0);
+        Q_ASSERT(_bezierCurves.size() % 3 == 0);
 
         if (_bezierCurves.isEmpty()) {
             qWarning("QEasingCurve: Invalid tcb curve");