diff --git a/QXlsx/header/xlsxdocument.h b/QXlsx/header/xlsxdocument.h
index 99004e64..492f1a6b 100644
--- a/QXlsx/header/xlsxdocument.h
+++ b/QXlsx/header/xlsxdocument.h
@@ -81,8 +81,8 @@ class QXLSX_EXPORT Document : public QObject
     bool addDataValidation(const DataValidation &validation);
     bool addConditionalFormatting(const ConditionalFormatting &cf);
 
-    Cell *cellAt(const CellReference &cell) const;
-    Cell *cellAt(int row, int col) const;
+    std::shared_ptr<Cell> cellAt(const CellReference &cell) const;
+    std::shared_ptr<Cell> cellAt(int row, int col) const;
 
     bool defineName(const QString &name,
                     const QString &formula,
diff --git a/QXlsx/header/xlsxdocument_p.h b/QXlsx/header/xlsxdocument_p.h
index 9f6a647b..ca00aaa5 100644
--- a/QXlsx/header/xlsxdocument_p.h
+++ b/QXlsx/header/xlsxdocument_p.h
@@ -32,7 +32,7 @@ class DocumentPrivate
     QString packageName;              // name of the .xlsx file
 
     QMap<QString, QString> documentProperties; // core, app and custom properties
-    QSharedPointer<Workbook> workbook;
+    std::shared_ptr<Workbook> workbook;
     std::shared_ptr<ContentTypes> contentTypes;
     bool isLoad;
 };
diff --git a/QXlsx/header/xlsxdrawinganchor_p.h b/QXlsx/header/xlsxdrawinganchor_p.h
index a876da54..3b933caf 100644
--- a/QXlsx/header/xlsxdrawinganchor_p.h
+++ b/QXlsx/header/xlsxdrawinganchor_p.h
@@ -8,7 +8,6 @@
 #include <memory>
 
 #include <QPoint>
-#include <QSharedPointer>
 #include <QSize>
 #include <QString>
 #include <QXmlStreamReader>
@@ -49,7 +48,7 @@ class DrawingAnchor
     void setObjectPicture(const QImage &img);
     bool getObjectPicture(QImage &img);
 
-    void setObjectGraphicFrame(QSharedPointer<Chart> chart);
+    void setObjectGraphicFrame(std::shared_ptr<QXlsx::Chart> chart);
 
     virtual bool loadFromXml(QXmlStreamReader &reader)     = 0;
     virtual void saveToXml(QXmlStreamWriter &writer) const = 0;
@@ -83,7 +82,7 @@ class DrawingAnchor
     Drawing *m_drawing;
     ObjectType m_objectType;
     std::shared_ptr<MediaFile> m_pictureFile;
-    QSharedPointer<Chart> m_chartFile;
+    std::shared_ptr<Chart> m_chartFile;
 
     int m_id;
 
diff --git a/QXlsx/header/xlsxstyles_p.h b/QXlsx/header/xlsxstyles_p.h
index 77c68abb..7c1c0ba8 100644
--- a/QXlsx/header/xlsxstyles_p.h
+++ b/QXlsx/header/xlsxstyles_p.h
@@ -36,11 +36,12 @@
 // We mean it.
 //
 
+#include <memory>
+
 #include <QHash>
 #include <QIODevice>
 #include <QList>
 #include <QMap>
-#include <QSharedPointer>
 #include <QStringList>
 #include <QVector>
 #include <QXmlStreamReader>
@@ -124,8 +125,8 @@ class Styles : public AbstractOOXmlFile
     bool readCellStyleXfs(QXmlStreamReader &reader);
 
     QHash<QString, int> m_builtinNumFmtsHash;
-    QMap<int, QSharedPointer<XlsxFormatNumberData>> m_customNumFmtIdMap;
-    QHash<QString, QSharedPointer<XlsxFormatNumberData>> m_customNumFmtsHash;
+    QMap<int, std::shared_ptr<XlsxFormatNumberData>> m_customNumFmtIdMap;
+    QHash<QString, std::shared_ptr<XlsxFormatNumberData>> m_customNumFmtsHash;
     int m_nextCustomNumFmtId;
     QList<Format> m_fontsList;
     QList<Format> m_fillsList;
diff --git a/QXlsx/header/xlsxworkbook.h b/QXlsx/header/xlsxworkbook.h
index 22e8e8bc..9ad3641c 100644
--- a/QXlsx/header/xlsxworkbook.h
+++ b/QXlsx/header/xlsxworkbook.h
@@ -12,7 +12,6 @@
 #include <QIODevice>
 #include <QImage>
 #include <QList>
-#include <QSharedPointer>
 
 QT_BEGIN_NAMESPACE_XLSX
 
@@ -70,8 +69,8 @@ class QXLSX_EXPORT Workbook : public AbstractOOXmlFile
     // internal used member
     void addMediaFile(std::shared_ptr<MediaFile> media, bool force = false);
     QList<std::shared_ptr<MediaFile>> mediaFiles() const;
-    void addChartFile(QSharedPointer<Chart> chartFile);
-    QList<QSharedPointer<Chart>> chartFiles() const;
+    void addChartFile(std::shared_ptr<Chart> chartFile);
+    QList<std::shared_ptr<Chart>> chartFiles() const;
 
 private:
     friend class Worksheet;
@@ -90,7 +89,7 @@ class QXLSX_EXPORT Workbook : public AbstractOOXmlFile
     Theme *theme();
     QList<QImage> images();
     QList<Drawing *> drawings();
-    QList<QSharedPointer<AbstractSheet>> getSheetsByTypes(AbstractSheet::SheetType type) const;
+    QList<std::shared_ptr<AbstractSheet>> getSheetsByTypes(AbstractSheet::SheetType type) const;
     QStringList worksheetNames() const;
     AbstractSheet *addSheet(const QString &name,
                             int sheetId,
diff --git a/QXlsx/header/xlsxworkbook_p.h b/QXlsx/header/xlsxworkbook_p.h
index 32abcbf9..19ae8584 100644
--- a/QXlsx/header/xlsxworkbook_p.h
+++ b/QXlsx/header/xlsxworkbook_p.h
@@ -9,7 +9,6 @@
 #include "xlsxtheme_p.h"
 #include "xlsxworkbook.h"
 
-#include <QSharedPointer>
 #include <QStringList>
 
 QT_BEGIN_NAMESPACE_XLSX
@@ -42,14 +41,14 @@ class WorkbookPrivate : public AbstractOOXmlFilePrivate
 public:
     WorkbookPrivate(Workbook *q, Workbook::CreateFlag flag);
 
-    QSharedPointer<SharedStrings> sharedStrings;
-    QList<QSharedPointer<AbstractSheet>> sheets;
-    QList<QSharedPointer<SimpleOOXmlFile>> externalLinks;
+    std::shared_ptr<SharedStrings> sharedStrings;
+    QList<std::shared_ptr<AbstractSheet>> sheets;
+    QList<std::shared_ptr<SimpleOOXmlFile>> externalLinks;
     QStringList sheetNames;
-    QSharedPointer<Styles> styles;
-    QSharedPointer<Theme> theme;
+    std::shared_ptr<Styles> styles;
+    std::shared_ptr<Theme> theme;
     QList<std::shared_ptr<MediaFile>> mediaFiles;
-    QList<QSharedPointer<Chart>> chartFiles;
+    QList<std::shared_ptr<Chart>> chartFiles;
     QList<XlsxDefineNameData> definedNamesList;
 
     bool strings_to_numbers_enabled;
diff --git a/QXlsx/header/xlsxworksheet.h b/QXlsx/header/xlsxworksheet.h
index 13774eef..cdeb0f1b 100644
--- a/QXlsx/header/xlsxworksheet.h
+++ b/QXlsx/header/xlsxworksheet.h
@@ -126,8 +126,8 @@ class QXLSX_EXPORT Worksheet : public AbstractSheet
     bool addDataValidation(const DataValidation &validation);
     bool addConditionalFormatting(const ConditionalFormatting &cf);
 
-    Cell *cellAt(const CellReference &row_column) const;
-    Cell *cellAt(int row, int column) const;
+    std::shared_ptr<Cell> cellAt(const CellReference &row_column) const;
+    std::shared_ptr<Cell> cellAt(int row, int column) const;
 
     int insertImage(int row, int column, const QImage &image);
     bool getImage(int imageIndex, QImage &img);
diff --git a/QXlsx/header/xlsxworksheet_p.h b/QXlsx/header/xlsxworksheet_p.h
index 7e32df90..ee784da7 100644
--- a/QXlsx/header/xlsxworksheet_p.h
+++ b/QXlsx/header/xlsxworksheet_p.h
@@ -10,13 +10,12 @@
 #include "xlsxdatavalidation.h"
 #include "xlsxworksheet.h"
 
+#include <QHash>
 #include <QImage>
 #include <QObject>
 #include <QRegularExpression>
-#include <QSharedPointer>
 #include <QString>
 #include <QVector>
-#include <QHash>
 
 class QXmlStreamWriter;
 class QXmlStreamReader;
@@ -136,30 +135,35 @@ struct XlsxColumnInfo {
 class CellTable
 {
 public:
-    static QList<int> sorteIntList(QList<int> &&keys) {
+    static QList<int> sorteIntList(QList<int> &&keys)
+    {
         std::sort(keys.begin(), keys.end());
         return keys;
     }
 
-    inline QList<int> sortedRows() const {
+    inline QList<int> sortedRows() const
+    {
         QList<int> keys = cells.keys();
         std::sort(keys.begin(), keys.end());
         return keys;
     }
 
-    void setValue(int row, int column, const std::shared_ptr<Cell> &cell) {
+    void setValue(int row, int column, const std::shared_ptr<Cell> &cell)
+    {
         cells[row].insert(column, cell);
-        firstRow = qMin(firstRow, row);
+        firstRow    = qMin(firstRow, row);
         firstColumn = qMin(firstColumn, column);
-        lastRow = qMin(lastRow, row);
-        lastColumn = qMin(lastColumn, column);
+        lastRow     = qMin(lastRow, row);
+        lastColumn  = qMin(lastColumn, column);
     }
 
-    std::shared_ptr<Cell> cellAt(int row, int column) const{
+    std::shared_ptr<Cell> cellAt(int row, int column) const
+    {
         return cells.value(row).value(column);
     }
 
-    bool contains(int row, int column) const{
+    bool contains(int row, int column) const
+    {
         auto it = cells.find(row);
         if (it != cells.end()) {
             return it->contains(column);
@@ -167,17 +171,15 @@ class CellTable
         return false;
     }
 
-    bool isEmpty() const {
-        return cells.isEmpty();
-    }
+    bool isEmpty() const { return cells.isEmpty(); }
 
     // It's faster with a single QHash, but in Qt5 it's capacity limits
     // how much cells we can hold
     QHash<int, QHash<int, std::shared_ptr<Cell>>> cells;
-    int firstRow = -1;
+    int firstRow    = -1;
     int firstColumn = -1;
-    int lastRow = -1;
-    int lastColumn = -1;
+    int lastRow     = -1;
+    int lastColumn  = -1;
 };
 
 class WorksheetPrivate : public AbstractSheetPrivate
@@ -217,8 +219,8 @@ class WorksheetPrivate : public AbstractSheetPrivate
     void loadXmlSheetViews(QXmlStreamReader &reader);
     void loadXmlHyperlinks(QXmlStreamReader &reader);
 
-    QList<QSharedPointer<XlsxRowInfo>> getRowInfoList(int rowFirst, int rowLast);
-    QList<QSharedPointer<XlsxColumnInfo>> getColumnInfoList(int colFirst, int colLast);
+    QList<std::shared_ptr<XlsxRowInfo>> getRowInfoList(int rowFirst, int rowLast);
+    QList<std::shared_ptr<XlsxColumnInfo>> getColumnInfoList(int colFirst, int colLast);
     QList<int> getColumnIndexes(int colFirst, int colLast);
     bool isColumnRangeValid(int colFirst, int colLast);
 
@@ -228,11 +230,11 @@ class WorksheetPrivate : public AbstractSheetPrivate
     CellTable cellTable;
 
     QHash<int, QHash<int, QString>> comments;
-    QHash<int, QHash<int, QSharedPointer<XlsxHyperlinkData>>> urlTable;
+    QHash<int, QHash<int, std::shared_ptr<XlsxHyperlinkData>>> urlTable;
     QList<CellRange> merges;
-    QHash<int, QSharedPointer<XlsxRowInfo>> rowsInfo;
-    QHash<int, QSharedPointer<XlsxColumnInfo>> colsInfo;
-    QHash<int, QSharedPointer<XlsxColumnInfo>> colsInfoHelper;
+    QHash<int, std::shared_ptr<XlsxRowInfo>> rowsInfo;
+    QHash<int, std::shared_ptr<XlsxColumnInfo>> colsInfo;
+    QHash<int, std::shared_ptr<XlsxColumnInfo>> colsInfoHelper;
 
     QList<DataValidation> dataValidationsList;
     QList<ConditionalFormatting> conditionalFormattingList;
diff --git a/QXlsx/source/xlsxchartsheet.cpp b/QXlsx/source/xlsxchartsheet.cpp
index 733d5aae..ea743d0e 100644
--- a/QXlsx/source/xlsxchartsheet.cpp
+++ b/QXlsx/source/xlsxchartsheet.cpp
@@ -48,11 +48,11 @@ Chartsheet::Chartsheet(const QString &name, int id, Workbook *workbook, CreateFl
         anchor->pos = QPoint(0, 0);
         anchor->ext = QSize(9293679, 6068786);
 
-        QSharedPointer<Chart> chart = QSharedPointer<Chart>(new Chart(this, flag));
+        auto chart = std::shared_ptr<Chart>(new Chart(this, flag));
         chart->setChartType(Chart::CT_BarChart);
         anchor->setObjectGraphicFrame(chart);
 
-        d_func()->chart = chart.data();
+        d_func()->chart = chart.get();
     }
 }
 
diff --git a/QXlsx/source/xlsxdocument.cpp b/QXlsx/source/xlsxdocument.cpp
index f0cef3f9..f5987f1a 100644
--- a/QXlsx/source/xlsxdocument.cpp
+++ b/QXlsx/source/xlsxdocument.cpp
@@ -25,7 +25,6 @@
 #include <QDir>
 #include <QFile>
 #include <QPointF>
-#include <QSharedPointer>
 #include <QTemporaryFile>
 
 /*
@@ -163,8 +162,8 @@ void DocumentPrivate::init()
     if (!contentTypes)
         contentTypes = std::make_shared<ContentTypes>(ContentTypes::F_NewFromScratch);
 
-    if (workbook.isNull())
-        workbook = QSharedPointer<Workbook>(new Workbook(Workbook::F_NewFromScratch));
+    if (!workbook)
+        workbook = std::shared_ptr<Workbook>(new Workbook(Workbook::F_NewFromScratch));
 }
 
 bool DocumentPrivate::loadPackage(QIODevice *device)
@@ -217,7 +216,7 @@ bool DocumentPrivate::loadPackage(QIODevice *device)
 
     // load workbook now, Get the workbook file path from the root rels file
     // In normal case, this should be "xl/workbook.xml"
-    workbook = QSharedPointer<Workbook>(new Workbook(Workbook::F_LoadFromExists));
+    workbook = std::shared_ptr<Workbook>(new Workbook(Workbook::F_LoadFromExists));
     QList<XlsxRelationship> rels_xl =
         rootRels.documentRelationships(QStringLiteral("/officeDocument"));
     if (rels_xl.isEmpty())
@@ -247,7 +246,7 @@ bool DocumentPrivate::loadPackage(QIODevice *device)
             path = xlworkbook_Dir + QLatin1String("/") + name;
         }
 
-        QSharedPointer<Styles> styles(new Styles(Styles::F_LoadFromExists));
+        std::shared_ptr<Styles> styles(new Styles(Styles::F_LoadFromExists));
         styles->loadFromXmlData(zipReader.fileData(path));
         workbook->d_func()->styles = styles;
     }
@@ -285,7 +284,7 @@ bool DocumentPrivate::loadPackage(QIODevice *device)
 
     // load external links
     for (int i = 0; i < workbook->d_func()->externalLinks.count(); ++i) {
-        SimpleOOXmlFile *link = workbook->d_func()->externalLinks[i].data();
+        SimpleOOXmlFile *link = workbook->d_func()->externalLinks[i].get();
         QString rel_path      = getRelFilePath(link->filePath());
         // If the .rel file exists, load it.
         if (zipReader.filePaths().contains(rel_path))
@@ -303,9 +302,9 @@ bool DocumentPrivate::loadPackage(QIODevice *device)
     }
 
     // load charts
-    QList<QSharedPointer<Chart>> chartFileToLoad = workbook->chartFiles();
+    QList<std::shared_ptr<Chart>> chartFileToLoad = workbook->chartFiles();
     for (int i = 0; i < chartFileToLoad.size(); ++i) {
-        QSharedPointer<Chart> cf = chartFileToLoad[i];
+        std::shared_ptr<Chart> cf = chartFileToLoad[i];
         cf->loadFromXmlData(zipReader.fileData(cf->filePath()));
     }
 
@@ -335,13 +334,13 @@ bool DocumentPrivate::savePackage(QIODevice *device) const
     DocPropsCore docPropsCore(DocPropsCore::F_NewFromScratch);
 
     // save worksheet xml files
-    QList<QSharedPointer<AbstractSheet>> worksheets =
+    QList<std::shared_ptr<AbstractSheet>> worksheets =
         workbook->getSheetsByTypes(AbstractSheet::ST_WorkSheet);
     if (!worksheets.isEmpty())
         docPropsApp.addHeadingPair(QStringLiteral("Worksheets"), worksheets.size());
 
     for (int i = 0; i < worksheets.size(); ++i) {
-        QSharedPointer<AbstractSheet> sheet = worksheets[i];
+        std::shared_ptr<AbstractSheet> sheet = worksheets[i];
         contentTypes->addWorksheetName(QStringLiteral("sheet%1").arg(i + 1));
         docPropsApp.addPartTitle(sheet->sheetName());
 
@@ -355,12 +354,12 @@ bool DocumentPrivate::savePackage(QIODevice *device) const
     }
 
     // save chartsheet xml files
-    QList<QSharedPointer<AbstractSheet>> chartsheets =
+    QList<std::shared_ptr<AbstractSheet>> chartsheets =
         workbook->getSheetsByTypes(AbstractSheet::ST_ChartSheet);
     if (!chartsheets.isEmpty())
         docPropsApp.addHeadingPair(QStringLiteral("Chartsheets"), chartsheets.size());
     for (int i = 0; i < chartsheets.size(); ++i) {
-        QSharedPointer<AbstractSheet> sheet = chartsheets[i];
+        std::shared_ptr<AbstractSheet> sheet = chartsheets[i];
         contentTypes->addWorksheetName(QStringLiteral("sheet%1").arg(i + 1));
         docPropsApp.addPartTitle(sheet->sheetName());
 
@@ -374,7 +373,7 @@ bool DocumentPrivate::savePackage(QIODevice *device) const
 
     // save external links xml files
     for (int i = 0; i < workbook->d_func()->externalLinks.count(); ++i) {
-        SimpleOOXmlFile *link = workbook->d_func()->externalLinks[i].data();
+        SimpleOOXmlFile *link = workbook->d_func()->externalLinks[i].get();
         contentTypes->addExternalLinkName(QStringLiteral("externalLink%1").arg(i + 1));
 
         zipWriter.addFile(QStringLiteral("xl/externalLinks/externalLink%1.xml").arg(i + 1),
@@ -437,7 +436,7 @@ bool DocumentPrivate::savePackage(QIODevice *device) const
     // save chart xml files
     for (int i = 0; i < workbook->chartFiles().size(); ++i) {
         contentTypes->addChartName(QStringLiteral("chart%1").arg(i + 1));
-        QSharedPointer<Chart> cf = workbook->chartFiles()[i];
+        std::shared_ptr<Chart> cf = workbook->chartFiles()[i];
         zipWriter.addFile(QStringLiteral("xl/charts/chart%1.xml").arg(i + 1), cf->saveToXmlData());
     }
 
@@ -573,7 +572,7 @@ bool DocumentPrivate::copyStyle(const QString &from, const QString &to)
     ZipReader zipReader(from);
     QStringList filePaths = zipReader.filePaths();
 
-    QSharedPointer<ZipReader> toReader = QSharedPointer<ZipReader>(new ZipReader(to));
+    std::shared_ptr<ZipReader> toReader = std::shared_ptr<ZipReader>(new ZipReader(to));
 
     QStringList toFilePaths = toReader->filePaths();
 
@@ -628,7 +627,7 @@ bool DocumentPrivate::copyStyle(const QString &from, const QString &to)
 
     temporalZip.close();
 
-    toReader.clear();
+    toReader.reset();
 
     tempFile.close();
 
@@ -1098,7 +1097,7 @@ bool Document::addConditionalFormatting(const ConditionalFormatting &cf)
  *
  * \sa read()
  */
-Cell *Document::cellAt(const CellReference &pos) const
+std::shared_ptr<Cell> Document::cellAt(const CellReference &pos) const
 {
     if (Worksheet *sheet = currentWorksheet())
         return sheet->cellAt(pos);
@@ -1111,11 +1110,11 @@ Cell *Document::cellAt(const CellReference &pos) const
  *
  * \sa read()
  */
-Cell *Document::cellAt(int row, int col) const
+std::shared_ptr<Cell> Document::cellAt(int row, int col) const
 {
     if (Worksheet *sheet = currentWorksheet())
         return sheet->cellAt(row, col);
-    return nullptr;
+    return {};
 }
 
 /*!
@@ -1203,7 +1202,7 @@ QStringList Document::documentPropertyNames() const
 Workbook *Document::workbook() const
 {
     Q_D(const Document);
-    return d->workbook.data();
+    return d->workbook.get();
 }
 
 /*!
diff --git a/QXlsx/source/xlsxdrawinganchor.cpp b/QXlsx/source/xlsxdrawinganchor.cpp
index 14e71792..30f294da 100644
--- a/QXlsx/source/xlsxdrawinganchor.cpp
+++ b/QXlsx/source/xlsxdrawinganchor.cpp
@@ -99,7 +99,7 @@ void DrawingAnchor::setObjectShape(const QImage &img)
 }
 //}}
 
-void DrawingAnchor::setObjectGraphicFrame(QSharedPointer<Chart> chart)
+void DrawingAnchor::setObjectGraphicFrame(std::shared_ptr<Chart> chart)
 {
     m_chartFile = chart;
     m_drawing->workbook->addChartFile(chart);
@@ -341,8 +341,8 @@ void DrawingAnchor::loadXmlObjectGraphicFrame(QXmlStreamReader &reader)
                 const auto parts = splitPath(m_drawing->filePath());
                 QString path     = QDir::cleanPath(parts.first() + QLatin1String("/") + name);
 
-                bool exist                       = false;
-                QList<QSharedPointer<Chart>> cfs = m_drawing->workbook->chartFiles();
+                bool exist                        = false;
+                QList<std::shared_ptr<Chart>> cfs = m_drawing->workbook->chartFiles();
                 for (int i = 0; i < cfs.size(); ++i) {
                     if (cfs[i]->filePath() == path) {
                         // already exist
@@ -351,8 +351,8 @@ void DrawingAnchor::loadXmlObjectGraphicFrame(QXmlStreamReader &reader)
                     }
                 }
                 if (!exist) {
-                    m_chartFile =
-                        QSharedPointer<Chart>(new Chart(m_drawing->sheet, Chart::F_LoadFromExists));
+                    m_chartFile = std::shared_ptr<Chart>(
+                        new Chart(m_drawing->sheet, Chart::F_LoadFromExists));
                     m_chartFile->setFilePath(path);
                     m_drawing->workbook->addChartFile(m_chartFile);
                 }
@@ -475,7 +475,7 @@ void DrawingAnchor::loadXmlObjectShape(QXmlStreamReader &reader)
                 rId=sp_blip_rembed;
                 QString name = m_drawing->relationships()->getRelationshipById(rId).target;
                 QString path = QDir::cleanPath(splitPath(m_drawing->filePath())[0] +
-    QLatin1String("/") + name); bool exist = false; QList<QSharedPointer<MediaFile> > mfs =
+    QLatin1String("/") + name); bool exist = false; QList<std::shared_ptr<MediaFile> > mfs =
     m_drawing->workbook->mediaFiles(); for (int i=0; i<mfs.size(); ++i)
                    {
                        if (mfs[i]->fileName() == path)
@@ -486,7 +486,7 @@ void DrawingAnchor::loadXmlObjectShape(QXmlStreamReader &reader)
                        }
                    }
                    if (!exist) {
-                       m_pictureFile = QSharedPointer<MediaFile> (new MediaFile(path));
+                       m_pictureFile = std::shared_ptr<MediaFile> (new MediaFile(path));
                        m_drawing->workbook->addMediaFile(m_pictureFile, true);
                    }
             }
diff --git a/QXlsx/source/xlsxstyles.cpp b/QXlsx/source/xlsxstyles.cpp
index 2695e8b9..e4247f7a 100644
--- a/QXlsx/source/xlsxstyles.cpp
+++ b/QXlsx/source/xlsxstyles.cpp
@@ -148,7 +148,7 @@ void Styles::fixNumFmt(const Format &format)
 
     const auto &str = format.numberFormat();
     if (!str.isEmpty()) {
-        QHash<QString, QSharedPointer<XlsxFormatNumberData>>::ConstIterator cIt;
+        QHash<QString, std::shared_ptr<XlsxFormatNumberData>>::ConstIterator cIt;
         // Assign proper number format index
         const auto &it = m_builtinNumFmtsHash.constFind(str);
         if (it != m_builtinNumFmtsHash.constEnd()) {
@@ -159,7 +159,7 @@ void Styles::fixNumFmt(const Format &format)
             // Assign a new fmt Id.
             const_cast<Format *>(&format)->fixNumberFormat(m_nextCustomNumFmtId, str);
 
-            QSharedPointer<XlsxFormatNumberData> fmt(new XlsxFormatNumberData);
+            auto fmt          = std::make_shared<XlsxFormatNumberData>();
             fmt->formatIndex  = m_nextCustomNumFmtId;
             fmt->formatString = str;
             m_customNumFmtIdMap.insert(m_nextCustomNumFmtId, fmt);
@@ -356,7 +356,7 @@ void Styles::writeNumFmts(QXmlStreamWriter &writer) const
     writer.writeStartElement(QStringLiteral("numFmts"));
     writer.writeAttribute(QStringLiteral("count"), QString::number(m_customNumFmtIdMap.count()));
 
-    QMapIterator<int, QSharedPointer<XlsxFormatNumberData>> it(m_customNumFmtIdMap);
+    QMapIterator<int, std::shared_ptr<XlsxFormatNumberData>> it(m_customNumFmtIdMap);
     while (it.hasNext()) {
         it.next();
         writer.writeEmptyElement(QStringLiteral("numFmt"));
@@ -779,9 +779,9 @@ bool Styles::readNumFmts(QXmlStreamReader &reader)
         if (reader.tokenType() == QXmlStreamReader::StartElement) {
             if (reader.name() == QLatin1String("numFmt")) {
                 const auto &attributes = reader.attributes();
-                QSharedPointer<XlsxFormatNumberData> fmt(new XlsxFormatNumberData);
-                fmt->formatIndex  = attributes.value(QLatin1String("numFmtId")).toInt();
-                fmt->formatString = attributes.value(QLatin1String("formatCode")).toString();
+                auto fmt               = std::make_shared<XlsxFormatNumberData>();
+                fmt->formatIndex       = attributes.value(QLatin1String("numFmtId")).toInt();
+                fmt->formatString      = attributes.value(QLatin1String("formatCode")).toString();
                 if (fmt->formatIndex >= m_nextCustomNumFmtId)
                     m_nextCustomNumFmtId = fmt->formatIndex + 1;
                 m_customNumFmtIdMap.insert(fmt->formatIndex, fmt);
diff --git a/QXlsx/source/xlsxworkbook.cpp b/QXlsx/source/xlsxworkbook.cpp
index 650dc298..39a0981f 100644
--- a/QXlsx/source/xlsxworkbook.cpp
+++ b/QXlsx/source/xlsxworkbook.cpp
@@ -26,9 +26,9 @@ QT_BEGIN_NAMESPACE_XLSX
 WorkbookPrivate::WorkbookPrivate(Workbook *q, Workbook::CreateFlag flag)
     : AbstractOOXmlFilePrivate(q, flag)
 {
-    sharedStrings = QSharedPointer<SharedStrings>(new SharedStrings(flag));
-    styles        = QSharedPointer<Styles>(new Styles(flag));
-    theme         = QSharedPointer<Theme>(new Theme(flag));
+    sharedStrings = std::make_shared<SharedStrings>(flag);
+    styles        = std::make_shared<Styles>(flag);
+    theme         = std::make_shared<Theme>(flag);
 
     x_window      = 240;
     y_window      = 15;
@@ -206,7 +206,7 @@ AbstractSheet *Workbook::addSheet(const QString &name, int sheetId, AbstractShee
         Q_ASSERT(false);
     }
 
-    d->sheets.append(QSharedPointer<AbstractSheet>(sheet));
+    d->sheets.append(std::shared_ptr<AbstractSheet>(sheet));
     d->sheetNames.append(name);
 
     return sheet;
@@ -253,7 +253,7 @@ AbstractSheet *Workbook::insertSheet(int index, const QString &name, AbstractShe
         Q_ASSERT(false);
     }
 
-    d->sheets.insert(index, QSharedPointer<AbstractSheet>(sheet));
+    d->sheets.insert(index, std::shared_ptr<AbstractSheet>(sheet));
     d->sheetNames.insert(index, sheetName);
     d->activesheetIndex = index;
 
@@ -268,7 +268,7 @@ AbstractSheet *Workbook::activeSheet() const
     Q_D(const Workbook);
     if (d->sheets.isEmpty())
         const_cast<Workbook *>(this)->addSheet();
-    return d->sheets[d->activesheetIndex].data();
+    return d->sheets[d->activesheetIndex].get();
 }
 
 bool Workbook::setActiveSheet(int index)
@@ -330,7 +330,7 @@ bool Workbook::moveSheet(int srcIndex, int distIndex)
     if (srcIndex < 0 || srcIndex >= d->sheets.size())
         return false;
 
-    QSharedPointer<AbstractSheet> sheet = d->sheets.takeAt(srcIndex);
+    std::shared_ptr<AbstractSheet> sheet = d->sheets.takeAt(srcIndex);
     d->sheetNames.takeAt(srcIndex);
     if (distIndex >= 0 || distIndex <= d->sheets.size()) {
         d->sheets.insert(distIndex, sheet);
@@ -364,7 +364,7 @@ bool Workbook::copySheet(int index, const QString &newName)
 
     ++d->last_sheet_id;
     AbstractSheet *sheet = d->sheets[index]->copy(worksheetName, d->last_sheet_id);
-    d->sheets.append(QSharedPointer<AbstractSheet>(sheet));
+    d->sheets.append(std::shared_ptr<AbstractSheet>(sheet));
     d->sheetNames.append(sheet->sheetName());
 
     return true; // #162
@@ -387,25 +387,25 @@ AbstractSheet *Workbook::sheet(int index) const
     Q_D(const Workbook);
     if (index < 0 || index >= d->sheets.size())
         return nullptr;
-    return d->sheets.at(index).data();
+    return d->sheets.at(index).get();
 }
 
 SharedStrings *Workbook::sharedStrings() const
 {
     Q_D(const Workbook);
-    return d->sharedStrings.data();
+    return d->sharedStrings.get();
 }
 
 Styles *Workbook::styles()
 {
     Q_D(Workbook);
-    return d->styles.data();
+    return d->styles.get();
 }
 
 Theme *Workbook::theme()
 {
     Q_D(Workbook);
-    return d->theme.data();
+    return d->theme.get();
 }
 
 /*!
@@ -418,7 +418,7 @@ QList<Drawing *> Workbook::drawings()
     Q_D(Workbook);
     QList<Drawing *> ds;
     for (int i = 0; i < d->sheets.size(); ++i) {
-        QSharedPointer<AbstractSheet> sheet = d->sheets[i];
+        std::shared_ptr<AbstractSheet> sheet = d->sheets[i];
         if (sheet->drawing())
             ds.append(sheet->drawing());
     }
@@ -429,10 +429,11 @@ QList<Drawing *> Workbook::drawings()
 /*!
  * \internal
  */
-QList<QSharedPointer<AbstractSheet>> Workbook::getSheetsByTypes(AbstractSheet::SheetType type) const
+QList<std::shared_ptr<AbstractSheet>>
+    Workbook::getSheetsByTypes(AbstractSheet::SheetType type) const
 {
     Q_D(const Workbook);
-    QList<QSharedPointer<AbstractSheet>> list;
+    QList<std::shared_ptr<AbstractSheet>> list;
     for (int i = 0; i < d->sheets.size(); ++i) {
         if (d->sheets[i]->sheetType() == type)
             list.append(d->sheets[i]);
@@ -490,7 +491,7 @@ void Workbook::saveToXmlFile(QIODevice *device) const
     int worksheetIndex  = 0;
     int chartsheetIndex = 0;
     for (int i = 0; i < d->sheets.size(); ++i) {
-        QSharedPointer<AbstractSheet> sheet = d->sheets[i];
+        std::shared_ptr<AbstractSheet> sheet = d->sheets[i];
         writer.writeEmptyElement(QStringLiteral("sheet"));
         writer.writeAttribute(QStringLiteral("name"), sheet->sheetName());
         writer.writeAttribute(QStringLiteral("sheetId"), QString::number(sheet->sheetId()));
@@ -653,7 +654,7 @@ bool Workbook::loadFromXmlFile(QIODevice *device)
                 const QString rId             = attributes.value(QLatin1String("r:id")).toString();
                 XlsxRelationship relationship = d->relationships->getRelationshipById(rId);
 
-                QSharedPointer<SimpleOOXmlFile> link(new SimpleOOXmlFile(F_LoadFromExists));
+                std::shared_ptr<SimpleOOXmlFile> link(new SimpleOOXmlFile(F_LoadFromExists));
 
                 const auto parts = splitPath(filePath());
                 QString fullPath =
@@ -714,7 +715,7 @@ void Workbook::addMediaFile(std::shared_ptr<MediaFile> media, bool force)
 /*!
  * \internal
  */
-QList<QSharedPointer<Chart>> Workbook::chartFiles() const
+QList<std::shared_ptr<Chart>> Workbook::chartFiles() const
 {
     Q_D(const Workbook);
 
@@ -724,7 +725,7 @@ QList<QSharedPointer<Chart>> Workbook::chartFiles() const
 /*!
  * \internal
  */
-void Workbook::addChartFile(QSharedPointer<Chart> chart)
+void Workbook::addChartFile(std::shared_ptr<Chart> chart)
 {
     Q_D(Workbook);
 
diff --git a/QXlsx/source/xlsxworksheet.cpp b/QXlsx/source/xlsxworksheet.cpp
index 804a4015..cebeb18b 100644
--- a/QXlsx/source/xlsxworksheet.cpp
+++ b/QXlsx/source/xlsxworksheet.cpp
@@ -75,8 +75,7 @@ void WorksheetPrivate::calculateSpans() const
     int span_max = -1;
 
     for (int row_num = dimension.firstRow(); row_num <= dimension.lastRow(); row_num++) {
-        for (int col_num = dimension.firstColumn(); col_num <= dimension.lastColumn();
-             col_num++) {
+        for (int col_num = dimension.firstColumn(); col_num <= dimension.lastColumn(); col_num++) {
             if (cellTable.contains(row_num, col_num)) {
                 if (span_max == -1) {
                     span_min = col_num;
@@ -511,7 +510,7 @@ QVariant Worksheet::read(int row, int column) const
 {
     Q_D(const Worksheet);
 
-    Cell *cell = cellAt(row, column);
+    auto cell = cellAt(row, column);
     if (!cell)
         return QVariant();
 
@@ -545,10 +544,10 @@ QVariant Worksheet::read(int row, int column) const
  * Returns the cell at the given \a row_column. If there
  * is no cell at the specified position, the function returns 0.
  */
-Cell *Worksheet::cellAt(const CellReference &row_column) const
+std::shared_ptr<Cell> Worksheet::cellAt(const CellReference &row_column) const
 {
     if (!row_column.isValid())
-        return nullptr;
+        return {};
 
     return cellAt(row_column.row(), row_column.column());
 }
@@ -557,10 +556,10 @@ Cell *Worksheet::cellAt(const CellReference &row_column) const
  * Returns the cell at the given \a row and \a column. If there
  * is no cell at the specified position, the function returns 0.
  */
-Cell *Worksheet::cellAt(int row, int col) const
+std::shared_ptr<Cell> Worksheet::cellAt(int row, int col) const
 {
     Q_D(const Worksheet);
-    return d->cellTable.cellAt(row, col).get();
+    return d->cellTable.cellAt(row, col);
 }
 
 Format WorksheetPrivate::cellFormat(int row, int col) const
@@ -611,7 +610,7 @@ bool Worksheet::writeString(int row, int column, const RichString &value, const
         fmt.mergeFormat(value.fragmentFormat(0));
     d->workbook->styles()->addXfFormat(fmt);
     auto cell = std::make_shared<Cell>(value.toPlainString(), Cell::SharedStringType, fmt, this);
-    cell->d_ptr->richString   = value;
+    cell->d_ptr->richString = value;
     d->cellTable.setValue(row, column, cell);
     return true;
 }
@@ -767,8 +766,8 @@ bool Worksheet::writeFormula(int row,
         d->sharedFormulaMap[si] = formula;
     }
 
-    auto data                 = std::make_shared<Cell>(result, Cell::NumberType, fmt, this);
-    data->d_ptr->formula      = formula;
+    auto data            = std::make_shared<Cell>(result, Cell::NumberType, fmt, this);
+    data->d_ptr->formula = formula;
     d->cellTable.setValue(row, column, data);
 
     CellRange range = formula.reference();
@@ -778,7 +777,7 @@ bool Worksheet::writeFormula(int row,
         for (int r = range.firstRow(); r <= range.lastRow(); ++r) {
             for (int c = range.firstColumn(); c <= range.lastColumn(); ++c) {
                 if (!(r == row && c == column)) {
-                    if (Cell *cell = cellAt(r, c)) {
+                    if (auto cell = cellAt(r, c)) {
                         cell->d_ptr->formula = sf;
                     } else {
                         auto newCell = std::make_shared<Cell>(result, Cell::NumberType, fmt, this);
@@ -1032,7 +1031,7 @@ bool Worksheet::writeHyperlink(int row,
     d->cellTable.setValue(row, column, cell);
 
     // Store the hyperlink data in a separate table
-    d->urlTable[row][column] = QSharedPointer<XlsxHyperlinkData>(new XlsxHyperlinkData(
+    d->urlTable[row][column] = std::shared_ptr<XlsxHyperlinkData>(new XlsxHyperlinkData(
         XlsxHyperlinkData::External, urlString, locationString, QString(), tip));
 
     return true;
@@ -1123,7 +1122,7 @@ bool Worksheet::getImage(int imageIndex, QImage &img)
     int realImageIndex = imageIndex - 1; // minus one
 
     DrawingAnchor *danchor = d->drawing->anchors.at(realImageIndex);
-    // QSharedPointer<Drawing> // for multithread
+    // std::shared_ptr<Drawing> // for multithread
     if (danchor == nullptr) {
         return false;
     }
@@ -1190,10 +1189,10 @@ Chart *Worksheet::insertChart(int row, int column, const QSize &size)
     anchor->from = XlsxMarker(row, column, 0, 0);
     anchor->ext  = size * 9525;
 
-    QSharedPointer<Chart> chart = QSharedPointer<Chart>(new Chart(this, F_NewFromScratch));
+    auto chart = std::shared_ptr<Chart>(new Chart(this, F_NewFromScratch));
     anchor->setObjectGraphicFrame(chart);
 
-    return chart.data();
+    return chart.get();
 }
 
 /*!
@@ -1219,7 +1218,7 @@ bool Worksheet::mergeCells(const CellRange &range, const Format &format)
     for (int row = range.firstRow(); row <= range.lastRow(); ++row) {
         for (int col = range.firstColumn(); col <= range.lastColumn(); ++col) {
             if (row == range.firstRow() && col == range.firstColumn()) {
-                Cell *cell = cellAt(row, col);
+                auto cell = cellAt(row, col);
                 if (cell) {
                     if (format.isValid())
                         cell->d_ptr->format = format;
@@ -1342,7 +1341,7 @@ void Worksheet::saveToXmlFile(QIODevice *device) const
         writer.writeStartElement(QStringLiteral("cols"));
 
         for (auto it = d->colsInfo.begin(); it != d->colsInfo.end(); ++it) {
-            QSharedPointer<XlsxColumnInfo> col_info = it.value();
+            std::shared_ptr<XlsxColumnInfo> col_info = it.value();
             writer.writeStartElement(QStringLiteral("col"));
             writer.writeAttribute(QStringLiteral("min"), QString::number(col_info->firstColumn));
             writer.writeAttribute(QStringLiteral("max"), QString::number(col_info->lastColumn));
@@ -1504,7 +1503,7 @@ void WorksheetPrivate::saveXmlSheetData(QXmlStreamWriter &writer) const
             writer.writeAttribute(QStringLiteral("spans"), span);
 
         if (riIt != rowsInfo.constEnd()) {
-            QSharedPointer<XlsxRowInfo> rowInfo = riIt.value();
+            std::shared_ptr<XlsxRowInfo> rowInfo = riIt.value();
             if (!rowInfo->format.isEmpty()) {
                 writer.writeAttribute(QStringLiteral("s"),
                                       QString::number(rowInfo->format.xfIndex()));
@@ -1566,7 +1565,8 @@ void WorksheetPrivate::saveXmlCellData(QXmlStreamWriter &writer,
         } else {
             auto cIt = colsInfoHelper.constFind(col);
             if (cIt != colsInfoHelper.constEnd() && !(*cIt)->format.isEmpty()) {
-                writer.writeAttribute(QStringLiteral("s"), QString::number((*cIt)->format.xfIndex()));
+                writer.writeAttribute(QStringLiteral("s"),
+                                      QString::number((*cIt)->format.xfIndex()));
             }
         }
     }
@@ -1724,9 +1724,9 @@ void WorksheetPrivate::saveXmlHyperlinks(QXmlStreamWriter &writer) const
         int row = it.key();
 
         for (auto it2 = it.value().begin(); it2 != it.value().end(); ++it2) {
-            int col                                = it2.key();
-            QSharedPointer<XlsxHyperlinkData> data = it2.value();
-            QString ref                            = CellReference(row, col).toString();
+            int col                                 = it2.key();
+            std::shared_ptr<XlsxHyperlinkData> data = it2.value();
+            QString ref                             = CellReference(row, col).toString();
 
             // dev57
             // writer.writeEmptyElement(QStringLiteral("hyperlink"));
@@ -1784,10 +1784,10 @@ void WorksheetPrivate::splitColsInfo(int colFirst, int colLast)
     // This will be more complex if we try to set "C:F" after "B:D".
     {
         for (auto it = colsInfo.begin(); it != colsInfo.end(); ++it) {
-            QSharedPointer<XlsxColumnInfo> info = it.value();
+            std::shared_ptr<XlsxColumnInfo> info = it.value();
             if (colFirst > info->firstColumn && colFirst <= info->lastColumn) {
                 // split the range,
-                QSharedPointer<XlsxColumnInfo> info2(new XlsxColumnInfo(*info));
+                std::shared_ptr<XlsxColumnInfo> info2(new XlsxColumnInfo(*info));
                 info->lastColumn   = colFirst - 1;
                 info2->firstColumn = colFirst;
                 colsInfo.insert(colFirst, info2);
@@ -1800,9 +1800,9 @@ void WorksheetPrivate::splitColsInfo(int colFirst, int colLast)
     }
     {
         for (auto it = colsInfo.begin(); it != colsInfo.end(); ++it) {
-            QSharedPointer<XlsxColumnInfo> info = it.value();
+            std::shared_ptr<XlsxColumnInfo> info = it.value();
             if (colLast >= info->firstColumn && colLast < info->lastColumn) {
-                QSharedPointer<XlsxColumnInfo> info2(new XlsxColumnInfo(*info));
+                std::shared_ptr<XlsxColumnInfo> info2(new XlsxColumnInfo(*info));
                 info->lastColumn   = colLast;
                 info2->firstColumn = colLast + 1;
                 colsInfo.insert(colLast + 1, info2);
@@ -1898,9 +1898,9 @@ bool Worksheet::setColumnWidth(int colFirst, int colLast, double width)
 {
     Q_D(Worksheet);
 
-    const QList<QSharedPointer<XlsxColumnInfo>> columnInfoList =
+    const QList<std::shared_ptr<XlsxColumnInfo>> columnInfoList =
         d->getColumnInfoList(colFirst, colLast);
-    for (const QSharedPointer<XlsxColumnInfo> &columnInfo : columnInfoList) {
+    for (const std::shared_ptr<XlsxColumnInfo> &columnInfo : columnInfoList) {
         columnInfo->width = width;
     }
 
@@ -1916,9 +1916,9 @@ bool Worksheet::setColumnFormat(int colFirst, int colLast, const Format &format)
 {
     Q_D(Worksheet);
 
-    const QList<QSharedPointer<XlsxColumnInfo>> columnInfoList =
+    const QList<std::shared_ptr<XlsxColumnInfo>> columnInfoList =
         d->getColumnInfoList(colFirst, colLast);
-    for (const QSharedPointer<XlsxColumnInfo> &columnInfo : columnInfoList)
+    for (const std::shared_ptr<XlsxColumnInfo> &columnInfo : columnInfoList)
         columnInfo->format = format;
 
     if (columnInfoList.count() > 0) {
@@ -1937,9 +1937,9 @@ bool Worksheet::setColumnHidden(int colFirst, int colLast, bool hidden)
 {
     Q_D(Worksheet);
 
-    const QList<QSharedPointer<XlsxColumnInfo>> columnInfoList =
+    const QList<std::shared_ptr<XlsxColumnInfo>> columnInfoList =
         d->getColumnInfoList(colFirst, colLast);
-    for (const QSharedPointer<XlsxColumnInfo> &columnInfo : columnInfoList)
+    for (const std::shared_ptr<XlsxColumnInfo> &columnInfo : columnInfoList)
         columnInfo->hidden = hidden;
 
     return (columnInfoList.count() > 0);
@@ -1952,7 +1952,7 @@ double Worksheet::columnWidth(int column)
 {
     Q_D(Worksheet);
 
-    QList<QSharedPointer<XlsxColumnInfo>> columnInfoList = d->getColumnInfoList(column, column);
+    QList<std::shared_ptr<XlsxColumnInfo>> columnInfoList = d->getColumnInfoList(column, column);
 
     // [dev54]
     if (columnInfoList.size() == 0) {
@@ -1983,7 +1983,7 @@ Format Worksheet::columnFormat(int column)
 {
     Q_D(Worksheet);
 
-    QList<QSharedPointer<XlsxColumnInfo>> columnInfoList = d->getColumnInfoList(column, column);
+    QList<std::shared_ptr<XlsxColumnInfo>> columnInfoList = d->getColumnInfoList(column, column);
     if (columnInfoList.count() == 1)
         return columnInfoList.at(0)->format;
 
@@ -1997,7 +1997,7 @@ bool Worksheet::isColumnHidden(int column)
 {
     Q_D(Worksheet);
 
-    QList<QSharedPointer<XlsxColumnInfo>> columnInfoList = d->getColumnInfoList(column, column);
+    QList<std::shared_ptr<XlsxColumnInfo>> columnInfoList = d->getColumnInfoList(column, column);
     if (columnInfoList.count() == 1)
         return columnInfoList.at(0)->hidden;
 
@@ -2015,8 +2015,8 @@ bool Worksheet::setRowHeight(int rowFirst, int rowLast, double height)
 {
     Q_D(Worksheet);
 
-    const QList<QSharedPointer<XlsxRowInfo>> rowInfoList = d->getRowInfoList(rowFirst, rowLast);
-    for (const QSharedPointer<XlsxRowInfo> &rowInfo : rowInfoList) {
+    const QList<std::shared_ptr<XlsxRowInfo>> rowInfoList = d->getRowInfoList(rowFirst, rowLast);
+    for (const std::shared_ptr<XlsxRowInfo> &rowInfo : rowInfoList) {
         rowInfo->height       = height;
         rowInfo->customHeight = true;
     }
@@ -2034,8 +2034,8 @@ bool Worksheet::setRowFormat(int rowFirst, int rowLast, const Format &format)
 {
     Q_D(Worksheet);
 
-    const QList<QSharedPointer<XlsxRowInfo>> rowInfoList = d->getRowInfoList(rowFirst, rowLast);
-    for (const QSharedPointer<XlsxRowInfo> &rowInfo : rowInfoList)
+    const QList<std::shared_ptr<XlsxRowInfo>> rowInfoList = d->getRowInfoList(rowFirst, rowLast);
+    for (const std::shared_ptr<XlsxRowInfo> &rowInfo : rowInfoList)
         rowInfo->format = format;
 
     d->workbook->styles()->addXfFormat(format);
@@ -2052,8 +2052,8 @@ bool Worksheet::setRowHidden(int rowFirst, int rowLast, bool hidden)
 {
     Q_D(Worksheet);
 
-    const QList<QSharedPointer<XlsxRowInfo>> rowInfoList = d->getRowInfoList(rowFirst, rowLast);
-    for (const QSharedPointer<XlsxRowInfo> &rowInfo : rowInfoList)
+    const QList<std::shared_ptr<XlsxRowInfo>> rowInfoList = d->getRowInfoList(rowFirst, rowLast);
+    for (const std::shared_ptr<XlsxRowInfo> &rowInfo : rowInfoList)
         rowInfo->hidden = hidden;
 
     return rowInfoList.count() > 0;
@@ -2117,7 +2117,7 @@ bool Worksheet::groupRows(int rowFirst, int rowLast, bool collapsed)
         if (it != d->rowsInfo.end()) {
             (*it)->outlineLevel += 1;
         } else {
-            QSharedPointer<XlsxRowInfo> info(new XlsxRowInfo);
+            std::shared_ptr<XlsxRowInfo> info(new XlsxRowInfo);
             info->outlineLevel += 1;
             it = d->rowsInfo.insert(row, info);
         }
@@ -2127,7 +2127,7 @@ bool Worksheet::groupRows(int rowFirst, int rowLast, bool collapsed)
     if (collapsed) {
         auto it = d->rowsInfo.find(rowLast + 1);
         if (it == d->rowsInfo.end())
-            it = d->rowsInfo.insert(rowLast + 1, QSharedPointer<XlsxRowInfo>(new XlsxRowInfo));
+            it = d->rowsInfo.insert(rowLast + 1, std::shared_ptr<XlsxRowInfo>(new XlsxRowInfo));
         (*it)->collapsed = true;
     }
     return true;
@@ -2178,7 +2178,7 @@ bool Worksheet::groupColumns(int colFirst, int colLast, bool collapsed)
                 (*it)->hidden = true;
         } else {
             int colEnd = (idx == nodes.size() - 1) ? colLast : nodes[idx + 1] - 1;
-            QSharedPointer<XlsxColumnInfo> info(new XlsxColumnInfo(colStart, colEnd, false));
+            std::shared_ptr<XlsxColumnInfo> info(new XlsxColumnInfo(colStart, colEnd, false));
             info->outlineLevel += 1;
             d->colsInfo.insert(colFirst, info);
             if (collapsed)
@@ -2195,7 +2195,7 @@ bool Worksheet::groupColumns(int colFirst, int colLast, bool collapsed)
         if (it != d->colsInfo.constEnd())
             (*it)->collapsed = true;
         else {
-            QSharedPointer<XlsxColumnInfo> info(new XlsxColumnInfo(col, col, false));
+            std::shared_ptr<XlsxColumnInfo> info(new XlsxColumnInfo(col, col, false));
             info->collapsed = true;
             d->colsInfo.insert(col, info);
             d->colsInfoHelper[col] = info;
@@ -2276,7 +2276,7 @@ void WorksheetPrivate::loadXmlSheetData(QXmlStreamReader &reader)
                     attributes.hasAttribute(QLatin1String("outlineLevel")) ||
                     attributes.hasAttribute(QLatin1String("collapsed"))) {
 
-                    QSharedPointer<XlsxRowInfo> info(new XlsxRowInfo);
+                    std::shared_ptr<XlsxRowInfo> info(new XlsxRowInfo);
                     if (attributes.hasAttribute(QLatin1String("customFormat")) &&
                         attributes.hasAttribute(QLatin1String("s"))) {
                         int idx      = attributes.value(QLatin1String("s")).toInt();
@@ -2321,8 +2321,7 @@ void WorksheetPrivate::loadXmlSheetData(QXmlStreamReader &reader)
                 QXmlStreamAttributes attributes = reader.attributes();
                 QString r                       = attributes.value(QLatin1String("r")).toString();
                 CellReference pos(r);
-                if (r.isEmpty())
-                {
+                if (r.isEmpty()) {
                     pos.setRow(row_num);
                     pos.setColumn(++col_num);
                 }
@@ -2464,7 +2463,7 @@ void WorksheetPrivate::loadXmlColumnsInfo(QXmlStreamReader &reader)
         reader.readNextStartElement();
         if (reader.tokenType() == QXmlStreamReader::StartElement) {
             if (reader.name() == QLatin1String("col")) {
-                QSharedPointer<XlsxColumnInfo> info(new XlsxColumnInfo(0, 1, false));
+                std::shared_ptr<XlsxColumnInfo> info(new XlsxColumnInfo(0, 1, false));
 
                 QXmlStreamAttributes colAttrs = reader.attributes();
                 int min                       = colAttrs.value(QLatin1String("min")).toInt();
@@ -2658,7 +2657,7 @@ void WorksheetPrivate::loadXmlHyperlinks(QXmlStreamReader &reader)
             QXmlStreamAttributes attrs = reader.attributes();
             CellReference pos(attrs.value(QLatin1String("ref")).toString());
             if (pos.isValid()) { // Valid
-                QSharedPointer<XlsxHyperlinkData> link(new XlsxHyperlinkData);
+                std::shared_ptr<XlsxHyperlinkData> link(new XlsxHyperlinkData);
                 link->display  = attrs.value(QLatin1String("display")).toString();
                 link->tooltip  = attrs.value(QLatin1String("tooltip")).toString();
                 link->location = attrs.value(QLatin1String("location")).toString();
@@ -2678,9 +2677,10 @@ void WorksheetPrivate::loadXmlHyperlinks(QXmlStreamReader &reader)
     }
 }
 
-QList<QSharedPointer<XlsxColumnInfo>> WorksheetPrivate::getColumnInfoList(int colFirst, int colLast)
+QList<std::shared_ptr<XlsxColumnInfo>> WorksheetPrivate::getColumnInfoList(int colFirst,
+                                                                           int colLast)
 {
-    QList<QSharedPointer<XlsxColumnInfo>> columnsInfoList;
+    QList<std::shared_ptr<XlsxColumnInfo>> columnsInfoList;
     if (isColumnRangeValid(colFirst, colLast)) {
         QList<int> nodes = getColumnIndexes(colFirst, colLast);
 
@@ -2691,7 +2691,7 @@ QList<QSharedPointer<XlsxColumnInfo>> WorksheetPrivate::getColumnInfoList(int co
                 columnsInfoList.append(*it);
             } else {
                 int colEnd = (idx == nodes.size() - 1) ? colLast : nodes[idx + 1] - 1;
-                QSharedPointer<XlsxColumnInfo> info(new XlsxColumnInfo(colStart, colEnd, false));
+                std::shared_ptr<XlsxColumnInfo> info(new XlsxColumnInfo(colStart, colEnd, false));
                 colsInfo.insert(colFirst, info);
                 columnsInfoList.append(info);
                 for (int c = colStart; c <= colEnd; ++c) {
@@ -2704,9 +2704,9 @@ QList<QSharedPointer<XlsxColumnInfo>> WorksheetPrivate::getColumnInfoList(int co
     return columnsInfoList;
 }
 
-QList<QSharedPointer<XlsxRowInfo>> WorksheetPrivate::getRowInfoList(int rowFirst, int rowLast)
+QList<std::shared_ptr<XlsxRowInfo>> WorksheetPrivate::getRowInfoList(int rowFirst, int rowLast)
 {
-    QList<QSharedPointer<XlsxRowInfo>> rowInfoList;
+    QList<std::shared_ptr<XlsxRowInfo>> rowInfoList;
 
     int min_col = dimension.firstColumn() < 1 ? 1 : dimension.firstColumn();
 
@@ -2714,9 +2714,9 @@ QList<QSharedPointer<XlsxRowInfo>> WorksheetPrivate::getRowInfoList(int rowFirst
         if (checkDimensions(row, min_col, false, true))
             continue;
 
-        QSharedPointer<XlsxRowInfo> rowInfo;
-        if ((rowsInfo[row]).isNull()) {
-            rowsInfo[row] = QSharedPointer<XlsxRowInfo>(new XlsxRowInfo());
+        std::shared_ptr<XlsxRowInfo> rowInfo;
+        if (!(rowsInfo[row])) {
+            rowsInfo[row] = std::make_shared<XlsxRowInfo>();
         }
         rowInfoList.append(rowsInfo[row]);
     }
@@ -2820,7 +2820,8 @@ void WorksheetPrivate::validateDimension()
     if (dimension.isValid() || cellTable.isEmpty())
         return;
 
-    CellRange cr(cellTable.firstRow, cellTable.firstColumn, cellTable.lastRow, cellTable.lastColumn);
+    CellRange cr(
+        cellTable.firstRow, cellTable.firstColumn, cellTable.lastRow, cellTable.lastColumn);
 
     if (cr.isValid())
         dimension = cr;
@@ -2858,11 +2859,11 @@ QVector<CellLocation> Worksheet::getFullCells(int *maxRow, int *maxCol)
     }
 
     for (const auto row : d->cellTable.sortedRows()) {
-        auto &columns = d->cellTable.cells[row];
+        auto &columns      = d->cellTable.cells[row];
         auto columnsSorted = CellTable::sorteIntList(columns.keys());
         for (const auto col : columnsSorted) {
-                   // It's faster to iterate but cellTable is unordered which might not
-                   // be what callers want?
+            // It's faster to iterate but cellTable is unordered which might not
+            // be what callers want?
             auto cell = std::make_shared<Cell>(columns.value(col).get());
 
             CellLocation cl;
diff --git a/TestExcel/extractdata.cpp b/TestExcel/extractdata.cpp
index 7694e718..b70d48e4 100644
--- a/TestExcel/extractdata.cpp
+++ b/TestExcel/extractdata.cpp
@@ -39,7 +39,7 @@ int extractdata()
     //![2]
     qDebug() << "extractdata.xlsx - QXlsx::Cell.value()";
     for (int row = 1; row < 10; ++row) {
-        if (QXlsx::Cell *cell = xlsx.cellAt(row, 1)) {
+        if (auto cell = xlsx.cellAt(row, 1)) {
             qDebug() << cell->value();
         }
     }
diff --git a/TestExcel/hello.cpp b/TestExcel/hello.cpp
index b73f8521..cf7bdbdb 100644
--- a/TestExcel/hello.cpp
+++ b/TestExcel/hello.cpp
@@ -126,7 +126,7 @@ int ReadExcel(bool isTest)
     //![2]
     qDebug() << " QXlsx::Cell.cellAt()";
     for (int row = 1; row < 20; ++row) {
-        Cell *cell = xlsx.cellAt(row, 1);
+        auto cell = xlsx.cellAt(row, 1);
         if (cell == NULL)
             continue;
         QVariant var   = cell->readValue();
diff --git a/TestExcel/readStyle.cpp b/TestExcel/readStyle.cpp
index 820df783..593894fd 100644
--- a/TestExcel/readStyle.cpp
+++ b/TestExcel/readStyle.cpp
@@ -41,7 +41,7 @@ int readGoogleSpreadsheet()
     // current sheet is default sheet. (Sheet1)
 
     for (int row = 1; row < 20; ++row) {
-        Cell *cell = xlsx.cellAt(row, 1);
+        auto cell = xlsx.cellAt(row, 1);
         if (cell == NULL)
             continue;
         QVariant var   = cell->readValue();
@@ -145,7 +145,7 @@ int readMSExcel201xNumber(QXlsx::Document *pXlsx)
         return (-1);
 
     for (int row = 1; row < 10; ++row) {
-        Cell *cell = pXlsx->cellAt(row, 1);
+        auto cell = pXlsx->cellAt(row, 1);
         if (cell == NULL)
             continue;