Code tidy - Clang-Tidy rule modernize-use-override

32 files changed, 81 insertions, 81 deletions

diff --git a/include/qpdf/BufferInputSource.hh b/include/qpdf/BufferInputSource.hh
index 2ef04a28..bd63f788 100644
--- a/include/qpdf/BufferInputSource.hh
+++ b/include/qpdf/BufferInputSource.hh
@@ -32,21 +32,21 @@ class QPDF_DLL_CLASS BufferInputSource: public InputSource
     QPDF_DLL
     BufferInputSource(std::string const& description, std::string const& contents);
     QPDF_DLL
-    virtual ~BufferInputSource();
+    ~BufferInputSource() override;
     QPDF_DLL
-    virtual qpdf_offset_t findAndSkipNextEOL();
+    qpdf_offset_t findAndSkipNextEOL() override;
     QPDF_DLL
-    virtual std::string const& getName() const;
+    std::string const& getName() const override;
     QPDF_DLL
-    virtual qpdf_offset_t tell();
+    qpdf_offset_t tell() override;
     QPDF_DLL
-    virtual void seek(qpdf_offset_t offset, int whence);
+    void seek(qpdf_offset_t offset, int whence) override;
     QPDF_DLL
-    virtual void rewind();
+    void rewind() override;
     QPDF_DLL
-    virtual size_t read(char* buffer, size_t length);
+    size_t read(char* buffer, size_t length) override;
     QPDF_DLL
-    virtual void unreadCh(char ch);
+    void unreadCh(char ch) override;
 
   private:
     bool own_memory;
diff --git a/include/qpdf/ClosedFileInputSource.hh b/include/qpdf/ClosedFileInputSource.hh
index 41c46242..1a6a9a0b 100644
--- a/include/qpdf/ClosedFileInputSource.hh
+++ b/include/qpdf/ClosedFileInputSource.hh
@@ -37,21 +37,21 @@ class QPDF_DLL_CLASS ClosedFileInputSource: public InputSource
     QPDF_DLL
     ClosedFileInputSource(char const* filename);
     QPDF_DLL
-    virtual ~ClosedFileInputSource();
+    ~ClosedFileInputSource() override;
     QPDF_DLL
-    virtual qpdf_offset_t findAndSkipNextEOL();
+    qpdf_offset_t findAndSkipNextEOL() override;
     QPDF_DLL
-    virtual std::string const& getName() const;
+    std::string const& getName() const override;
     QPDF_DLL
-    virtual qpdf_offset_t tell();
+    qpdf_offset_t tell() override;
     QPDF_DLL
-    virtual void seek(qpdf_offset_t offset, int whence);
+    void seek(qpdf_offset_t offset, int whence) override;
     QPDF_DLL
-    virtual void rewind();
+    void rewind() override;
     QPDF_DLL
-    virtual size_t read(char* buffer, size_t length);
+    size_t read(char* buffer, size_t length) override;
     QPDF_DLL
-    virtual void unreadCh(char ch);
+    void unreadCh(char ch) override;
 
     // The file stays open between calls to stayOpen(true) and stayOpen(false). You can use this to
     // surround multiple operations on a single ClosedFileInputSource to reduce the overhead of a
diff --git a/include/qpdf/FileInputSource.hh b/include/qpdf/FileInputSource.hh
index 71adad7b..ed9ae6c6 100644
--- a/include/qpdf/FileInputSource.hh
+++ b/include/qpdf/FileInputSource.hh
@@ -35,21 +35,21 @@ class QPDF_DLL_CLASS FileInputSource: public InputSource
     QPDF_DLL
     void setFile(char const* description, FILE* filep, bool close_file);
     QPDF_DLL
-    virtual ~FileInputSource();
+    ~FileInputSource() override;
     QPDF_DLL
-    virtual qpdf_offset_t findAndSkipNextEOL();
+    qpdf_offset_t findAndSkipNextEOL() override;
     QPDF_DLL
-    virtual std::string const& getName() const;
+    std::string const& getName() const override;
     QPDF_DLL
-    virtual qpdf_offset_t tell();
+    qpdf_offset_t tell() override;
     QPDF_DLL
-    virtual void seek(qpdf_offset_t offset, int whence);
+    void seek(qpdf_offset_t offset, int whence) override;
     QPDF_DLL
-    virtual void rewind();
+    void rewind() override;
     QPDF_DLL
-    virtual size_t read(char* buffer, size_t length);
+    size_t read(char* buffer, size_t length) override;
     QPDF_DLL
-    virtual void unreadCh(char ch);
+    void unreadCh(char ch) override;
 
   private:
     FileInputSource(FileInputSource const&) = delete;
diff --git a/include/qpdf/Pl_Concatenate.hh b/include/qpdf/Pl_Concatenate.hh
index 24977de1..bee1bcf3 100644
--- a/include/qpdf/Pl_Concatenate.hh
+++ b/include/qpdf/Pl_Concatenate.hh
@@ -32,13 +32,13 @@ class QPDF_DLL_CLASS Pl_Concatenate: public Pipeline
     QPDF_DLL
     Pl_Concatenate(char const* identifier, Pipeline* next);
     QPDF_DLL
-    virtual ~Pl_Concatenate();
+    ~Pl_Concatenate() override;
 
     QPDF_DLL
-    virtual void write(unsigned char const* data, size_t len);
+    void write(unsigned char const* data, size_t len) override;
 
     QPDF_DLL
-    virtual void finish();
+    void finish() override;
 
     // At the very end, call manualFinish to actually finish the rest of the pipeline.
     QPDF_DLL
diff --git a/include/qpdf/Pl_Count.hh b/include/qpdf/Pl_Count.hh
index 51338607..3601f8de 100644
--- a/include/qpdf/Pl_Count.hh
+++ b/include/qpdf/Pl_Count.hh
@@ -30,11 +30,11 @@ class QPDF_DLL_CLASS Pl_Count: public Pipeline
     QPDF_DLL
     Pl_Count(char const* identifier, Pipeline* next);
     QPDF_DLL
-    virtual ~Pl_Count();
+    ~Pl_Count() override;
     QPDF_DLL
-    virtual void write(unsigned char const*, size_t);
+    void write(unsigned char const*, size_t) override;
     QPDF_DLL
-    virtual void finish();
+    void finish() override;
     // Returns the number of bytes written
     QPDF_DLL
     qpdf_offset_t getCount() const;
diff --git a/include/qpdf/Pl_DCT.hh b/include/qpdf/Pl_DCT.hh
index e4f6345f..b7e6b1e3 100644
--- a/include/qpdf/Pl_DCT.hh
+++ b/include/qpdf/Pl_DCT.hh
@@ -56,12 +56,12 @@ class QPDF_DLL_CLASS Pl_DCT: public Pipeline
         CompressConfig* config_callback = nullptr);
 
     QPDF_DLL
-    virtual ~Pl_DCT();
+    ~Pl_DCT() override;
 
     QPDF_DLL
-    virtual void write(unsigned char const* data, size_t len);
+    void write(unsigned char const* data, size_t len) override;
     QPDF_DLL
-    virtual void finish();
+    void finish() override;
 
   private:
     QPDF_DLL_PRIVATE
diff --git a/include/qpdf/Pl_Discard.hh b/include/qpdf/Pl_Discard.hh
index b2733a66..2eddf13d 100644
--- a/include/qpdf/Pl_Discard.hh
+++ b/include/qpdf/Pl_Discard.hh
@@ -31,11 +31,11 @@ class QPDF_DLL_CLASS Pl_Discard: public Pipeline
     QPDF_DLL
     Pl_Discard();
     QPDF_DLL
-    virtual ~Pl_Discard();
+    ~Pl_Discard() override;
     QPDF_DLL
-    virtual void write(unsigned char const*, size_t);
+    void write(unsigned char const*, size_t) override;
     QPDF_DLL
-    virtual void finish();
+    void finish() override;
 
   private:
     class QPDF_DLL_PRIVATE Members
diff --git a/include/qpdf/Pl_Flate.hh b/include/qpdf/Pl_Flate.hh
index c31d4a0b..14009b2a 100644
--- a/include/qpdf/Pl_Flate.hh
+++ b/include/qpdf/Pl_Flate.hh
@@ -40,12 +40,12 @@ class QPDF_DLL_CLASS Pl_Flate: public Pipeline
         action_e action,
         unsigned int out_bufsize = def_bufsize);
     QPDF_DLL
-    virtual ~Pl_Flate();
+    ~Pl_Flate() override;
 
     QPDF_DLL
-    virtual void write(unsigned char const* data, size_t len);
+    void write(unsigned char const* data, size_t len) override;
     QPDF_DLL
-    virtual void finish();
+    void finish() override;
 
     // Globally set compression level from 1 (fastest, least
     // compression) to 9 (slowest, most compression). Use -1 to set
diff --git a/include/qpdf/Pl_Function.hh b/include/qpdf/Pl_Function.hh
index c9d5550d..afd421a3 100644
--- a/include/qpdf/Pl_Function.hh
+++ b/include/qpdf/Pl_Function.hh
@@ -54,12 +54,12 @@ class QPDF_DLL_CLASS Pl_Function: public Pipeline
     Pl_Function(char const* identifier, Pipeline* next, writer_c_char_t fn, void* udata);
 
     QPDF_DLL
-    virtual ~Pl_Function();
+    ~Pl_Function() override;
 
     QPDF_DLL
-    virtual void write(unsigned char const* buf, size_t len);
+    void write(unsigned char const* buf, size_t len) override;
     QPDF_DLL
-    virtual void finish();
+    void finish() override;
 
   private:
     class QPDF_DLL_PRIVATE Members
diff --git a/include/qpdf/Pl_OStream.hh b/include/qpdf/Pl_OStream.hh
index 3ea21c93..9aeaac4d 100644
--- a/include/qpdf/Pl_OStream.hh
+++ b/include/qpdf/Pl_OStream.hh
@@ -36,12 +36,12 @@ class QPDF_DLL_CLASS Pl_OStream: public Pipeline
     QPDF_DLL
     Pl_OStream(char const* identifier, std::ostream& os);
     QPDF_DLL
-    virtual ~Pl_OStream();
+    ~Pl_OStream() override;
 
     QPDF_DLL
-    virtual void write(unsigned char const* buf, size_t len);
+    void write(unsigned char const* buf, size_t len) override;
     QPDF_DLL
-    virtual void finish();
+    void finish() override;
 
   private:
     class QPDF_DLL_PRIVATE Members
diff --git a/include/qpdf/Pl_QPDFTokenizer.hh b/include/qpdf/Pl_QPDFTokenizer.hh
index 5bc6cb87..79cbda7b 100644
--- a/include/qpdf/Pl_QPDFTokenizer.hh
+++ b/include/qpdf/Pl_QPDFTokenizer.hh
@@ -45,11 +45,11 @@ class QPDF_DLL_CLASS Pl_QPDFTokenizer: public Pipeline
     Pl_QPDFTokenizer(
         char const* identifier, QPDFObjectHandle::TokenFilter* filter, Pipeline* next = nullptr);
     QPDF_DLL
-    virtual ~Pl_QPDFTokenizer();
+    ~Pl_QPDFTokenizer() override;
     QPDF_DLL
-    virtual void write(unsigned char const* buf, size_t len);
+    void write(unsigned char const* buf, size_t len) override;
     QPDF_DLL
-    virtual void finish();
+    void finish() override;
 
   private:
     class QPDF_DLL_PRIVATE Members
diff --git a/include/qpdf/Pl_RunLength.hh b/include/qpdf/Pl_RunLength.hh
index 86782535..e04bce2d 100644
--- a/include/qpdf/Pl_RunLength.hh
+++ b/include/qpdf/Pl_RunLength.hh
@@ -29,12 +29,12 @@ class QPDF_DLL_CLASS Pl_RunLength: public Pipeline
     QPDF_DLL
     Pl_RunLength(char const* identifier, Pipeline* next, action_e action);
     QPDF_DLL
-    virtual ~Pl_RunLength();
+    ~Pl_RunLength() override;
 
     QPDF_DLL
-    virtual void write(unsigned char const* data, size_t len);
+    void write(unsigned char const* data, size_t len) override;
     QPDF_DLL
-    virtual void finish();
+    void finish() override;
 
   private:
     QPDF_DLL_PRIVATE
diff --git a/include/qpdf/Pl_StdioFile.hh b/include/qpdf/Pl_StdioFile.hh
index 90190d2b..fb994459 100644
--- a/include/qpdf/Pl_StdioFile.hh
+++ b/include/qpdf/Pl_StdioFile.hh
@@ -36,12 +36,12 @@ class QPDF_DLL_CLASS Pl_StdioFile: public Pipeline
     QPDF_DLL
     Pl_StdioFile(char const* identifier, FILE* f);
     QPDF_DLL
-    virtual ~Pl_StdioFile();
+    ~Pl_StdioFile() override;
 
     QPDF_DLL
-    virtual void write(unsigned char const* buf, size_t len);
+    void write(unsigned char const* buf, size_t len) override;
     QPDF_DLL
-    virtual void finish();
+    void finish() override;
 
   private:
     class QPDF_DLL_PRIVATE Members
diff --git a/include/qpdf/Pl_String.hh b/include/qpdf/Pl_String.hh
index 8f712fbf..dc720c90 100644
--- a/include/qpdf/Pl_String.hh
+++ b/include/qpdf/Pl_String.hh
@@ -41,12 +41,12 @@ class QPDF_DLL_CLASS Pl_String: public Pipeline
     QPDF_DLL
     Pl_String(char const* identifier, Pipeline* next, std::string& s);
     QPDF_DLL
-    virtual ~Pl_String();
+    ~Pl_String() override;
 
     QPDF_DLL
-    virtual void write(unsigned char const* buf, size_t len);
+    void write(unsigned char const* buf, size_t len) override;
     QPDF_DLL
-    virtual void finish();
+    void finish() override;
 
   private:
     class QPDF_DLL_PRIVATE Members
diff --git a/include/qpdf/QPDF.hh b/include/qpdf/QPDF.hh
index ee0a7b79..e54947d9 100644
--- a/include/qpdf/QPDF.hh
+++ b/include/qpdf/QPDF.hh
@@ -942,8 +942,8 @@ class QPDF
     {
       public:
         CopiedStreamDataProvider(QPDF& destination_qpdf);
-        virtual ~CopiedStreamDataProvider() = default;
-        virtual bool provideStreamData(
+        ~CopiedStreamDataProvider() override = default;
+        bool provideStreamData(
             QPDFObjGen const& og,
             Pipeline* pipeline,
             bool suppress_warnings,
@@ -963,8 +963,8 @@ class QPDF
 
       public:
         StringDecrypter(QPDF* qpdf, QPDFObjGen const& og);
-        virtual ~StringDecrypter() = default;
-        virtual void decryptString(std::string& val);
+        ~StringDecrypter() override = default;
+        void decryptString(std::string& val) override;
 
       private:
         QPDF* qpdf;
@@ -1308,9 +1308,9 @@ class QPDF
             checker(checker)
         {
         }
-        virtual ~PatternFinder() = default;
-        virtual bool
-        check()
+        ~PatternFinder() override = default;
+        bool
+        check() override
         {
             return (this->qpdf.*checker)();
         }
diff --git a/include/qpdf/QPDFAcroFormDocumentHelper.hh b/include/qpdf/QPDFAcroFormDocumentHelper.hh
index a86563fa..8be4d069 100644
--- a/include/qpdf/QPDFAcroFormDocumentHelper.hh
+++ b/include/qpdf/QPDFAcroFormDocumentHelper.hh
@@ -71,7 +71,7 @@ class QPDFAcroFormDocumentHelper: public QPDFDocumentHelper
     QPDF_DLL
     QPDFAcroFormDocumentHelper(QPDF&);
     QPDF_DLL
-    virtual ~QPDFAcroFormDocumentHelper() = default;
+    ~QPDFAcroFormDocumentHelper() override = default;
 
     // This class lazily creates an internal cache of the mapping among form fields, annotations,
     // and pages. Methods within this class preserve the validity of this cache. However, if you
diff --git a/include/qpdf/QPDFAnnotationObjectHelper.hh b/include/qpdf/QPDFAnnotationObjectHelper.hh
index b93f895f..69ec77b4 100644
--- a/include/qpdf/QPDFAnnotationObjectHelper.hh
+++ b/include/qpdf/QPDFAnnotationObjectHelper.hh
@@ -30,7 +30,7 @@ class QPDFAnnotationObjectHelper: public QPDFObjectHelper
     QPDF_DLL
     QPDFAnnotationObjectHelper(QPDFObjectHandle);
     QPDF_DLL
-    virtual ~QPDFAnnotationObjectHelper() = default;
+    ~QPDFAnnotationObjectHelper() override = default;
 
     // This class provides helper methods for annotations. More functionality will likely be added
     // in the future.
diff --git a/include/qpdf/QPDFEFStreamObjectHelper.hh b/include/qpdf/QPDFEFStreamObjectHelper.hh
index cdb5c278..2d55cca7 100644
--- a/include/qpdf/QPDFEFStreamObjectHelper.hh
+++ b/include/qpdf/QPDFEFStreamObjectHelper.hh
@@ -35,7 +35,7 @@ class QPDFEFStreamObjectHelper: public QPDFObjectHelper
     QPDF_DLL
     QPDFEFStreamObjectHelper(QPDFObjectHandle);
     QPDF_DLL
-    virtual ~QPDFEFStreamObjectHelper() = default;
+    ~QPDFEFStreamObjectHelper() override = default;
 
     // Date parameters are strings that conform to the PDF spec for date/time strings, which is
     // "D:yyyymmddhhmmss<z>" where <z> is either "Z" for UTC or "-hh'mm'" or "+hh'mm'" for timezone
diff --git a/include/qpdf/QPDFEmbeddedFileDocumentHelper.hh b/include/qpdf/QPDFEmbeddedFileDocumentHelper.hh
index 4727feef..b4633369 100644
--- a/include/qpdf/QPDFEmbeddedFileDocumentHelper.hh
+++ b/include/qpdf/QPDFEmbeddedFileDocumentHelper.hh
@@ -39,7 +39,7 @@ class QPDFEmbeddedFileDocumentHelper: public QPDFDocumentHelper
     QPDF_DLL
     QPDFEmbeddedFileDocumentHelper(QPDF&);
     QPDF_DLL
-    virtual ~QPDFEmbeddedFileDocumentHelper() = default;
+    ~QPDFEmbeddedFileDocumentHelper() override = default;
 
     QPDF_DLL
     bool hasEmbeddedFiles() const;
diff --git a/include/qpdf/QPDFExc.hh b/include/qpdf/QPDFExc.hh
index 1a9e16f2..daa52a47 100644
--- a/include/qpdf/QPDFExc.hh
+++ b/include/qpdf/QPDFExc.hh
@@ -37,7 +37,7 @@ class QPDF_DLL_CLASS QPDFExc: public std::runtime_error
         qpdf_offset_t offset,
         std::string const& message);
     QPDF_DLL
-    virtual ~QPDFExc() noexcept = default;
+    ~QPDFExc() noexcept override = default;
 
     // To get a complete error string, call what(), provided by std::exception.  The accessors below
     // return the original values used to create the exception.  Only the error code and message are
diff --git a/include/qpdf/QPDFFileSpecObjectHelper.hh b/include/qpdf/QPDFFileSpecObjectHelper.hh
index 9b6474df..6001f09d 100644
--- a/include/qpdf/QPDFFileSpecObjectHelper.hh
+++ b/include/qpdf/QPDFFileSpecObjectHelper.hh
@@ -35,7 +35,7 @@ class QPDFFileSpecObjectHelper: public QPDFObjectHelper
     QPDF_DLL
     QPDFFileSpecObjectHelper(QPDFObjectHandle);
     QPDF_DLL
-    virtual ~QPDFFileSpecObjectHelper() = default;
+    ~QPDFFileSpecObjectHelper() override = default;
 
     QPDF_DLL
     std::string getDescription();
diff --git a/include/qpdf/QPDFFormFieldObjectHelper.hh b/include/qpdf/QPDFFormFieldObjectHelper.hh
index fbd5547f..156ccc64 100644
--- a/include/qpdf/QPDFFormFieldObjectHelper.hh
+++ b/include/qpdf/QPDFFormFieldObjectHelper.hh
@@ -37,7 +37,7 @@ class QPDFFormFieldObjectHelper: public QPDFObjectHelper
     QPDF_DLL
     QPDFFormFieldObjectHelper(QPDFObjectHandle);
     QPDF_DLL
-    virtual ~QPDFFormFieldObjectHelper() = default;
+    ~QPDFFormFieldObjectHelper() override = default;
 
     QPDF_DLL
     bool isNull();
diff --git a/include/qpdf/QPDFNameTreeObjectHelper.hh b/include/qpdf/QPDFNameTreeObjectHelper.hh
index 90cb6856..1d344a6c 100644
--- a/include/qpdf/QPDFNameTreeObjectHelper.hh
+++ b/include/qpdf/QPDFNameTreeObjectHelper.hh
@@ -50,7 +50,7 @@ class QPDF_DLL_CLASS QPDFNameTreeObjectHelper: public QPDFObjectHelper
     static QPDFNameTreeObjectHelper newEmpty(QPDF&, bool auto_repair = true);
 
     QPDF_DLL
-    virtual ~QPDFNameTreeObjectHelper();
+    ~QPDFNameTreeObjectHelper() override;
 
     // Return whether the name tree has an explicit entry for this name.
     QPDF_DLL
diff --git a/include/qpdf/QPDFNumberTreeObjectHelper.hh b/include/qpdf/QPDFNumberTreeObjectHelper.hh
index 12603af0..fe55a28f 100644
--- a/include/qpdf/QPDFNumberTreeObjectHelper.hh
+++ b/include/qpdf/QPDFNumberTreeObjectHelper.hh
@@ -44,7 +44,7 @@ class QPDF_DLL_CLASS QPDFNumberTreeObjectHelper: public QPDFObjectHelper
     QPDFNumberTreeObjectHelper(QPDFObjectHandle, QPDF&, bool auto_repair = true);
 
     QPDF_DLL
-    virtual ~QPDFNumberTreeObjectHelper();
+    ~QPDFNumberTreeObjectHelper() override;
 
     // Create an empty number tree
     QPDF_DLL
diff --git a/include/qpdf/QPDFOutlineDocumentHelper.hh b/include/qpdf/QPDFOutlineDocumentHelper.hh
index eb5f8f9a..1d249969 100644
--- a/include/qpdf/QPDFOutlineDocumentHelper.hh
+++ b/include/qpdf/QPDFOutlineDocumentHelper.hh
@@ -41,7 +41,7 @@ class QPDFOutlineDocumentHelper: public QPDFDocumentHelper
     QPDF_DLL
     QPDFOutlineDocumentHelper(QPDF&);
     QPDF_DLL
-    virtual ~QPDFOutlineDocumentHelper() = default;
+    ~QPDFOutlineDocumentHelper() override = default;
 
     QPDF_DLL
     bool hasOutlines();
diff --git a/include/qpdf/QPDFOutlineObjectHelper.hh b/include/qpdf/QPDFOutlineObjectHelper.hh
index d9868949..6b42f509 100644
--- a/include/qpdf/QPDFOutlineObjectHelper.hh
+++ b/include/qpdf/QPDFOutlineObjectHelper.hh
@@ -34,7 +34,7 @@ class QPDFOutlineObjectHelper: public QPDFObjectHelper
 {
   public:
     QPDF_DLL
-    virtual ~QPDFOutlineObjectHelper()
+    ~QPDFOutlineObjectHelper() override
     {
         // This must be cleared explicitly to avoid circular references that prevent cleanup of
         // shared pointers.
diff --git a/include/qpdf/QPDFPageDocumentHelper.hh b/include/qpdf/QPDFPageDocumentHelper.hh
index a6005a45..b408fdd2 100644
--- a/include/qpdf/QPDFPageDocumentHelper.hh
+++ b/include/qpdf/QPDFPageDocumentHelper.hh
@@ -37,7 +37,7 @@ class QPDFPageDocumentHelper: public QPDFDocumentHelper
     QPDF_DLL
     QPDFPageDocumentHelper(QPDF&);
     QPDF_DLL
-    virtual ~QPDFPageDocumentHelper() = default;
+    ~QPDFPageDocumentHelper() override = default;
 
     // Traverse page tree, and return all /Page objects wrapped in QPDFPageObjectHelper objects.
     // Unlike with QPDF::getAllPages, the vector of pages returned by this call is not affected by
diff --git a/include/qpdf/QPDFPageLabelDocumentHelper.hh b/include/qpdf/QPDFPageLabelDocumentHelper.hh
index 64e85869..741329cb 100644
--- a/include/qpdf/QPDFPageLabelDocumentHelper.hh
+++ b/include/qpdf/QPDFPageLabelDocumentHelper.hh
@@ -44,7 +44,7 @@ class QPDFPageLabelDocumentHelper: public QPDFDocumentHelper
     QPDF_DLL
     QPDFPageLabelDocumentHelper(QPDF&);
     QPDF_DLL
-    virtual ~QPDFPageLabelDocumentHelper() = default;
+    ~QPDFPageLabelDocumentHelper() override = default;
 
     QPDF_DLL
     bool hasPageLabels();
diff --git a/include/qpdf/QPDFPageObjectHelper.hh b/include/qpdf/QPDFPageObjectHelper.hh
index 120df104..a5be1dee 100644
--- a/include/qpdf/QPDFPageObjectHelper.hh
+++ b/include/qpdf/QPDFPageObjectHelper.hh
@@ -39,7 +39,7 @@ class QPDFPageObjectHelper: public QPDFObjectHelper
     QPDF_DLL
     QPDFPageObjectHelper(QPDFObjectHandle);
     QPDF_DLL
-    virtual ~QPDFPageObjectHelper() = default;
+    ~QPDFPageObjectHelper() override = default;
 
     // PAGE ATTRIBUTES
 
diff --git a/include/qpdf/QPDFSystemError.hh b/include/qpdf/QPDFSystemError.hh
index 7833b070..cdc3e386 100644
--- a/include/qpdf/QPDFSystemError.hh
+++ b/include/qpdf/QPDFSystemError.hh
@@ -32,7 +32,7 @@ class QPDF_DLL_CLASS QPDFSystemError: public std::runtime_error
     QPDF_DLL
     QPDFSystemError(std::string const& description, int system_errno);
     QPDF_DLL
-    virtual ~QPDFSystemError() noexcept = default;
+    ~QPDFSystemError() noexcept override = default;
 
     // To get a complete error string, call what(), provided by std::exception.  The accessors below
     // return the original values used to create the exception.
diff --git a/include/qpdf/QPDFUsage.hh b/include/qpdf/QPDFUsage.hh
index 538392a0..16fbb867 100644
--- a/include/qpdf/QPDFUsage.hh
+++ b/include/qpdf/QPDFUsage.hh
@@ -30,7 +30,7 @@ class QPDF_DLL_CLASS QPDFUsage: public std::runtime_error
     QPDF_DLL
     QPDFUsage(std::string const& msg);
     QPDF_DLL
-    virtual ~QPDFUsage() noexcept = default;
+    ~QPDFUsage() noexcept override = default;
 };
 
 #endif // QPDFUSAGE_HH
diff --git a/include/qpdf/QPDFWriter.hh b/include/qpdf/QPDFWriter.hh
index 34720119..be2d6f2e 100644
--- a/include/qpdf/QPDFWriter.hh
+++ b/include/qpdf/QPDFWriter.hh
@@ -92,7 +92,7 @@ class QPDFWriter
         QPDF_DLL
         FunctionProgressReporter(std::function<void(int)>);
         QPDF_DLL
-        virtual ~FunctionProgressReporter();
+        ~FunctionProgressReporter() override;
         QPDF_DLL
         void reportProgress(int) override;