Introduce o3tl::optional as an alias for std::optional

...with a boost::optional fallback for Xcode < 10 (as std::optional is only
available starting with Xcode 10 according to
<https://en.cppreference.com/w/cpp/compiler_support>, and our baseline for iOS
and macOS is still Xcode 9.3 according to README.md).  And mechanically rewrite
all code to use o3tl::optional instead of boost::optional.

One immediate benefit is that disabling -Wmaybe-uninitialized for GCC as per
fed7c3deb3f4ec81f78967c2d7f3c4554398cb9d "Slience bogus
-Werror=maybe-uninitialized" should no longer be necessary (and whose check
happened to no longer trigger for GCC 10 trunk, even though that compiler would
still emit bogus -Wmaybe-uninitialized for uses of boost::optional under
--enable-optimized, which made me ponder whether this switch from
boost::optional to std::optional would be a useful thing to do; I keep that
configure.ac check for now, though, and will only remove it in a follow up
commit).

Another longer-term benefit is that the code is now already in good shape for an
eventual switch to std::optional (a switch we would have done anyway once we no
longer need to support Xcode < 10).

Only desktop/qa/desktop_lib/test_desktop_lib.cxx heavily uses
boost::property_tree::ptree::get_child_optional returning boost::optional, so
let it keep using boost::optional for now.

After a number of preceding commits have paved the way for this change, this
commit is completely mechanical, done with

> git ls-files -z | grep -vz -e '^bin/find-unneeded-includes$' -e '^configure.ac$' -e '^desktop/qa/desktop_lib/test_desktop_lib.cxx$' -e '^dictionaries$' -e '^external/' -e '^helpcontent2$' -e '^include/IwyuFilter_include.yaml$' -e '^sc/IwyuFilter_sc.yaml$' -e '^solenv/gdb/boost/optional.py$' -e '^solenv/vs/LibreOffice.natvis$' -e '^translations$' -e '\.svg$' | xargs -0 sed -i -E -e 's|\<boost(/optional)?/optional\.hpp\>|o3tl/optional.hxx|g' -e 's/\<boost(\s*)::(\s*)(make_)?optional\>/o3tl\1::\2\3optional/g' -e 's/\<boost(\s*)::(\s*)none\>/o3tl\1::\2nullopt/g'

(before committing include/o3tl/optional.hxx, and relying on some GNU features).
It excludes some files where mention of boost::optional et al should apparently
not be changed (and the sub-repo directory stubs).  It turned out that all uses
of boost::none across the code base were in combination with boost::optional, so
had all to be rewritten as o3tl::nullopt.

Change-Id: Ibfd9f4b3d5a8aee6e6eed310b988c4e5ffd8b11b
Reviewed-on: https://gerrit.libreoffice.org/84128
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

34 files changed, 175 insertions, 129 deletions

diff --git a/include/comphelper/configuration.hxx b/include/comphelper/configuration.hxx
index cb2ad5675660..7c2a0a7fb4ec 100644
--- a/include/comphelper/configuration.hxx
+++ b/include/comphelper/configuration.hxx
@@ -12,7 +12,7 @@
 
 #include <sal/config.h>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #include <com/sun/star/uno/Any.hxx>
 #include <com/sun/star/uno/Reference.h>
 #include <comphelper/comphelperdllapi.h>
@@ -158,18 +158,18 @@ private:
 };
 
 /// @internal
-template< typename T > struct Convert< boost::optional< T > >
+template< typename T > struct Convert< o3tl::optional< T > >
 {
-    static css::uno::Any toAny(boost::optional< T > const & value) {
+    static css::uno::Any toAny(o3tl::optional< T > const & value) {
         return value
             ? css::uno::makeAny(*value)
             : css::uno::Any();
     }
 
-    static boost::optional< T > fromAny(css::uno::Any const & value)
+    static o3tl::optional< T > fromAny(css::uno::Any const & value)
     {
         return value.hasValue()
-            ? boost::optional< T >(value.get< T >()) : boost::optional< T >();
+            ? o3tl::optional< T >(value.get< T >()) : o3tl::optional< T >();
     }
 
 private:
@@ -200,7 +200,7 @@ template< typename T, typename U > struct ConfigurationProperty
 
     /// Get the value of the given (non-localized) configuration property.
     ///
-    /// For nillable properties, U is of type boost::optional<U'>.
+    /// For nillable properties, U is of type o3tl::optional<U'>.
     static U get(
         css::uno::Reference< css::uno::XComponentContext >
             const & context = comphelper::getProcessComponentContext())
@@ -216,7 +216,7 @@ template< typename T, typename U > struct ConfigurationProperty
     /// Set the value of the given (non-localized) configuration property, via a
     /// given changes batch.
     ///
-    /// For nillable properties, U is of type boost::optional<U'>.
+    /// For nillable properties, U is of type o3tl::optional<U'>.
     static void set(
         U const & value,
         std::shared_ptr< ConfigurationChanges > const & batch)
@@ -244,7 +244,7 @@ template< typename T, typename U > struct ConfigurationLocalizedProperty
     /// locale currently set at the
     /// com.sun.star.configuration.theDefaultProvider.
     ///
-    /// For nillable properties, U is of type boost::optional<U'>.
+    /// For nillable properties, U is of type o3tl::optional<U'>.
     static U get(css::uno::Reference< css::uno::XComponentContext > const & context)
     {
         // Folding this into one statement causes a bogus error at least with
@@ -260,7 +260,7 @@ template< typename T, typename U > struct ConfigurationLocalizedProperty
     /// com.sun.star.configuration.theDefaultProvider, via a given changes
     /// batch.
     ///
-    /// For nillable properties, U is of type boost::optional<U'>.
+    /// For nillable properties, U is of type o3tl::optional<U'>.
     static void set(
         U const & value,
         std::shared_ptr< ConfigurationChanges > const & batch)
diff --git a/include/comphelper/logging.hxx b/include/comphelper/logging.hxx
index 5057ff9d838f..1fa7601519db 100644
--- a/include/comphelper/logging.hxx
+++ b/include/comphelper/logging.hxx
@@ -23,7 +23,7 @@
 #include <comphelper/comphelperdllapi.h>
 #include <rtl/ustring.hxx>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #include <memory>
 
 namespace com::sun::star::uno { template <class interface_type> class Reference; }
@@ -65,7 +65,7 @@ namespace comphelper
     //= EventLogger
 
     class EventLogger_Impl;
-    typedef ::boost::optional< OUString >    OptionalString;
+    typedef ::o3tl::optional< OUString >    OptionalString;
 
     /** encapsulates a css::logging::XLogger
 
diff --git a/include/comphelper/unwrapargs.hxx b/include/comphelper/unwrapargs.hxx
index 7c1d26d3a0aa..3ba4e213c266 100644
--- a/include/comphelper/unwrapargs.hxx
+++ b/include/comphelper/unwrapargs.hxx
@@ -22,7 +22,7 @@
 
 #include <sal/config.h>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 
 #include <rtl/ustrbuf.hxx>
 #include <com/sun/star/uno/Sequence.hxx>
@@ -67,7 +67,7 @@ namespace detail {
     template< typename T, typename... Args >
     inline void unwrapArgs(
         const css::uno::Sequence< css::uno::Any >& seq,
-        sal_Int32 nArg, ::boost::optional< T >& v, Args&... args );
+        sal_Int32 nArg, ::o3tl::optional< T >& v, Args&... args );
 
     template< typename T, typename... Args >
     inline void unwrapArgs(
@@ -95,7 +95,7 @@ namespace detail {
     template< typename T, typename... Args >
     inline void unwrapArgs(
         const css::uno::Sequence< css::uno::Any >& seq,
-        sal_Int32 nArg, ::boost::optional< T >& v, Args&... args )
+        sal_Int32 nArg, ::o3tl::optional< T >& v, Args&... args )
     {
         if( nArg < seq.getLength() )
         {
diff --git a/include/connectivity/sqlerror.hxx b/include/connectivity/sqlerror.hxx
index 9b4c60c49476..9b75657290f4 100644
--- a/include/connectivity/sqlerror.hxx
+++ b/include/connectivity/sqlerror.hxx
@@ -22,7 +22,7 @@
 
 #include <com/sun/star/sdbc/SQLException.hpp>
 #include <connectivity/dbtoolsdllapi.hxx>
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #include <memory>
 
 namespace connectivity
@@ -61,11 +61,11 @@ namespace connectivity
 
         // - optional
 
-        /** convenience wrapper around boost::optional, allowing implicit construction
+        /** convenience wrapper around o3tl::optional, allowing implicit construction
         */
-        class ParamValue : public ::boost::optional< OUString >
+        class ParamValue : public ::o3tl::optional< OUString >
         {
-            typedef ::boost::optional< OUString >  base_type;
+            typedef ::o3tl::optional< OUString >  base_type;
 
         public:
             ParamValue( ) : base_type( ) { }
diff --git a/include/cppcanvas/renderer.hxx b/include/cppcanvas/renderer.hxx
index 113bda783f20..ed1dc04a11f7 100644
--- a/include/cppcanvas/renderer.hxx
+++ b/include/cppcanvas/renderer.hxx
@@ -22,7 +22,7 @@
 
 #include <sal/types.h>
 #include <rtl/ustring.hxx>
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #include <basegfx/matrix/b2dhommatrix.hxx>
 #include <cppcanvas/canvasgraphic.hxx>
 #include <cppcanvas/color.hxx>
@@ -100,16 +100,16 @@ namespace cppcanvas
         struct Parameters
         {
             /// Optionally forces the fill color attribute for all actions
-            ::boost::optional< IntSRGBA >                  maFillColor;
+            ::o3tl::optional< IntSRGBA >                  maFillColor;
 
             /// Optionally forces the line color attribute for all actions
-            ::boost::optional< IntSRGBA >                 maLineColor;
+            ::o3tl::optional< IntSRGBA >                 maLineColor;
 
             /// Optionally forces the text color attribute for all actions
-            ::boost::optional< IntSRGBA >                  maTextColor;
+            ::o3tl::optional< IntSRGBA >                  maTextColor;
 
             /// Optionally forces the given fontname for all text actions
-            ::boost::optional< OUString >                  maFontName;
+            ::o3tl::optional< OUString >                  maFontName;
 
             /** Optionally transforms all text output actions with the
                 given matrix (in addition to the overall canvas
@@ -119,16 +119,16 @@ namespace cppcanvas
                 rect coordinate system, i.e. the metafile is assumed
                 to be contained in the unit rect.
              */
-            ::boost::optional< ::basegfx::B2DHomMatrix >    maTextTransformation;
+            ::o3tl::optional< ::basegfx::B2DHomMatrix >    maTextTransformation;
 
             /// Optionally forces the given font weight for all text actions
-            ::boost::optional< sal_Int8 >                   maFontWeight;
+            ::o3tl::optional< sal_Int8 >                   maFontWeight;
 
             /// Optionally forces the given font letter form (italics etc.) for all text actions
-            ::boost::optional< sal_Int8 >                   maFontLetterForm;
+            ::o3tl::optional< sal_Int8 >                   maFontLetterForm;
 
             /// Optionally forces underlining for all text actions
-            ::boost::optional< bool >                       maFontUnderline;
+            ::o3tl::optional< bool >                       maFontUnderline;
         };
     };
 
diff --git a/include/dbaccess/genericcontroller.hxx b/include/dbaccess/genericcontroller.hxx
index 0d4d460ad886..a63144ef76ab 100644
--- a/include/dbaccess/genericcontroller.hxx
+++ b/include/dbaccess/genericcontroller.hxx
@@ -27,7 +27,7 @@
 #include <memory>
 #include <vector>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 
 #include <com/sun/star/awt/XUserInputInterception.hpp>
 #include <com/sun/star/frame/CommandGroup.hpp>
@@ -94,7 +94,7 @@ namespace dbaui
     class ODataView;
 
     template< typename T >
-    inline bool SAL_CALL operator >>= (const css::uno::Any& _any, boost::optional< T >& _value)
+    inline bool SAL_CALL operator >>= (const css::uno::Any& _any, o3tl::optional< T >& _value)
     {
         _value.reset();  // de-init the optional value
 
@@ -118,10 +118,10 @@ namespace dbaui
     {
         bool                        bEnabled;
 
-        boost::optional<bool> bChecked;
-        boost::optional<bool> bInvisible;
+        o3tl::optional<bool> bChecked;
+        o3tl::optional<bool> bInvisible;
         css::uno::Any               aValue;
-        boost::optional<OUString> sTitle;
+        o3tl::optional<OUString> sTitle;
 
         FeatureState() : bEnabled(false) { }
     };
diff --git a/include/editeng/editeng.hxx b/include/editeng/editeng.hxx
index 12b4b0b28398..01dcffe10022 100644
--- a/include/editeng/editeng.hxx
+++ b/include/editeng/editeng.hxx
@@ -23,7 +23,7 @@
 #include <memory>
 #include <vector>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 
 #include <com/sun/star/uno/Reference.h>
 #include <com/sun/star/i18n/WordType.hpp>
@@ -506,7 +506,7 @@ public:
     virtual OUString  GetUndoComment( sal_uInt16 nUndoId ) const;
     virtual bool    SpellNextDocument();
     virtual void    FieldClicked( const SvxFieldItem& rField );
-    virtual OUString CalcFieldValue( const SvxFieldItem& rField, sal_Int32 nPara, sal_Int32 nPos, boost::optional<Color>& rTxtColor, boost::optional<Color>& rFldColor );
+    virtual OUString CalcFieldValue( const SvxFieldItem& rField, sal_Int32 nPara, sal_Int32 nPos, o3tl::optional<Color>& rTxtColor, o3tl::optional<Color>& rFldColor );
 
     // override this if access to bullet information needs to be provided
     virtual const SvxNumberFormat * GetNumberFormat( sal_Int32 nPara ) const;
diff --git a/include/editeng/outliner.hxx b/include/editeng/outliner.hxx
index 70c08e5e45ee..2f6cc2d9abf3 100644
--- a/include/editeng/outliner.hxx
+++ b/include/editeng/outliner.hxx
@@ -40,7 +40,7 @@
 #include <editeng/paragraphdata.hxx>
 #include <o3tl/typed_flags_set.hxx>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #include <functional>
 #include <memory>
 #include <vector>
@@ -484,8 +484,8 @@ private:
     Outliner*           pOutliner;
     const SvxFieldItem& rFldItem;
 
-    boost::optional<Color> mxTxtColor;
-    boost::optional<Color> mxFldColor;
+    o3tl::optional<Color> mxTxtColor;
+    o3tl::optional<Color> mxFldColor;
 
     OUString            aRepresentation;
 
@@ -509,11 +509,11 @@ public:
 
     const SvxFieldItem& GetField() const { return rFldItem; }
 
-    boost::optional<Color> const & GetTextColor() const { return mxTxtColor; }
-    void            SetTextColor( boost::optional<Color> xCol ) { mxTxtColor = xCol; }
+    o3tl::optional<Color> const & GetTextColor() const { return mxTxtColor; }
+    void            SetTextColor( o3tl::optional<Color> xCol ) { mxTxtColor = xCol; }
 
-    boost::optional<Color> const & GetFieldColor() const { return mxFldColor; }
-    void            SetFieldColor( boost::optional<Color> xCol ) { mxFldColor = xCol; }
+    o3tl::optional<Color> const & GetFieldColor() const { return mxFldColor; }
+    void            SetFieldColor( o3tl::optional<Color> xCol ) { mxFldColor = xCol; }
 
     sal_Int32       GetPara() const { return nPara; }
     sal_Int32       GetPos() const { return nPos; }
@@ -880,7 +880,7 @@ public:
     bool            UpdateFields();
     void            RemoveFields( const std::function<bool ( const SvxFieldData* )>& isFieldData = [] (const SvxFieldData* ){return true;} );
 
-    virtual OUString CalcFieldValue( const SvxFieldItem& rField, sal_Int32 nPara, sal_Int32 nPos, boost::optional<Color>& rTxtColor, boost::optional<Color>& rFldColor );
+    virtual OUString CalcFieldValue( const SvxFieldItem& rField, sal_Int32 nPara, sal_Int32 nPos, o3tl::optional<Color>& rTxtColor, o3tl::optional<Color>& rFldColor );
 
     void            SetSpeller( css::uno::Reference< css::linguistic2::XSpellChecker1 > const &xSpeller );
     css::uno::Reference< css::linguistic2::XSpellChecker1 > const &
diff --git a/include/editeng/svxacorr.hxx b/include/editeng/svxacorr.hxx
index 46c3df27f18f..cde80d6aca83 100644
--- a/include/editeng/svxacorr.hxx
+++ b/include/editeng/svxacorr.hxx
@@ -28,7 +28,7 @@
 #include <editeng/swafopt.hxx>
 #include <editeng/editengdllapi.h>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #include <map>
 #include <memory>
 
@@ -155,7 +155,7 @@ public:
                            ~SvxAutocorrWordList();
     void                   DeleteAndDestroyAll();
     const SvxAutocorrWord* Insert(SvxAutocorrWord aWord) const;
-    boost::optional<SvxAutocorrWord> FindAndRemove(const SvxAutocorrWord *pWord);
+    o3tl::optional<SvxAutocorrWord> FindAndRemove(const SvxAutocorrWord *pWord);
     void                   LoadEntry(const OUString& sWrong, const OUString& sRight, bool bOnlyTxt);
     bool                   empty() const;
 
diff --git a/include/editeng/unoedprx.hxx b/include/editeng/unoedprx.hxx
index 132cbbf96c66..a3aa0b915cc3 100644
--- a/include/editeng/unoedprx.hxx
+++ b/include/editeng/unoedprx.hxx
@@ -54,7 +54,7 @@ public:
 
     virtual SfxItemPool*    GetPool() const override;
 
-    virtual OUString        CalcFieldValue( const SvxFieldItem& rField, sal_Int32 nPara, sal_Int32 nPos, boost::optional<Color>& rpTxtColor, boost::optional<Color>& rpFldColor ) override;
+    virtual OUString        CalcFieldValue( const SvxFieldItem& rField, sal_Int32 nPara, sal_Int32 nPos, o3tl::optional<Color>& rpTxtColor, o3tl::optional<Color>& rpFldColor ) override;
     virtual void            FieldClicked( const SvxFieldItem& rField ) override;
 
     virtual bool            IsValid() const override;
diff --git a/include/editeng/unoedsrc.hxx b/include/editeng/unoedsrc.hxx
index e9f3ee0dd093..ab8a567d78d2 100644
--- a/include/editeng/unoedsrc.hxx
+++ b/include/editeng/unoedsrc.hxx
@@ -159,7 +159,7 @@ public:
     virtual void        QuickSetAttribs( const SfxItemSet& rSet, const ESelection& rSel ) = 0;
     virtual void        QuickInsertLineBreak( const ESelection& rSel ) = 0;
 
-    virtual OUString    CalcFieldValue( const SvxFieldItem& rField, sal_Int32 nPara, sal_Int32 nPos, boost::optional<Color>& rpTxtColor, boost::optional<Color>& rpFldColor ) = 0;
+    virtual OUString    CalcFieldValue( const SvxFieldItem& rField, sal_Int32 nPara, sal_Int32 nPos, o3tl::optional<Color>& rpTxtColor, o3tl::optional<Color>& rpFldColor ) = 0;
     virtual void        FieldClicked( const SvxFieldItem& rField ) = 0;
 
     virtual SfxItemPool* GetPool() const = 0;
diff --git a/include/editeng/unofored.hxx b/include/editeng/unofored.hxx
index 8222a3043bdb..a0cf70caf5f8 100644
--- a/include/editeng/unofored.hxx
+++ b/include/editeng/unofored.hxx
@@ -54,7 +54,7 @@ public:
 
     virtual SfxItemPool* GetPool() const override;
 
-    virtual OUString     CalcFieldValue( const SvxFieldItem& rField, sal_Int32 nPara, sal_Int32 nPos, boost::optional<Color>& rpTxtColor, boost::optional<Color>& rpFldColor ) override;
+    virtual OUString     CalcFieldValue( const SvxFieldItem& rField, sal_Int32 nPara, sal_Int32 nPos, o3tl::optional<Color>& rpTxtColor, o3tl::optional<Color>& rpFldColor ) override;
     virtual void         FieldClicked( const SvxFieldItem& rField ) override;
     virtual bool         IsValid() const override;
 
diff --git a/include/editeng/unoforou.hxx b/include/editeng/unoforou.hxx
index f2d28a53e405..17029f9ca85c 100644
--- a/include/editeng/unoforou.hxx
+++ b/include/editeng/unoforou.hxx
@@ -72,7 +72,7 @@ public:
 
     virtual SfxItemPool* GetPool() const override;
 
-    virtual OUString    CalcFieldValue( const SvxFieldItem& rField, sal_Int32 nPara, sal_Int32 nPos, boost::optional<Color>& rpTxtColor, boost::optional<Color>& rpFldColor ) override;
+    virtual OUString    CalcFieldValue( const SvxFieldItem& rField, sal_Int32 nPara, sal_Int32 nPos, o3tl::optional<Color>& rpTxtColor, o3tl::optional<Color>& rpFldColor ) override;
     virtual void        FieldClicked( const SvxFieldItem& rField ) override;
 
     virtual bool        IsValid() const override;
diff --git a/include/editeng/unotext.hxx b/include/editeng/unotext.hxx
index 203bf309809d..4fae9a92dfe3 100644
--- a/include/editeng/unotext.hxx
+++ b/include/editeng/unotext.hxx
@@ -189,7 +189,7 @@ public:
     virtual void            QuickSetAttribs( const SfxItemSet& rSet, const ESelection& rSel ) override;
     virtual void            QuickInsertLineBreak( const ESelection& rSel ) override;
 
-    virtual OUString        CalcFieldValue( const SvxFieldItem& rField, sal_Int32 nPara, sal_Int32 nPos, boost::optional<Color>& rpTxtColor, boost::optional<Color>& rpFldColor ) override;
+    virtual OUString        CalcFieldValue( const SvxFieldItem& rField, sal_Int32 nPara, sal_Int32 nPos, o3tl::optional<Color>& rpTxtColor, o3tl::optional<Color>& rpFldColor ) override;
     virtual void            FieldClicked( const SvxFieldItem& rField ) override;
 
     virtual bool            IsValid() const override;
diff --git a/include/filter/msfilter/msdffimp.hxx b/include/filter/msfilter/msdffimp.hxx
index 341dc2b5329e..efb71e6737ee 100644
--- a/include/filter/msfilter/msdffimp.hxx
+++ b/include/filter/msfilter/msdffimp.hxx
@@ -28,7 +28,7 @@
 #include <vector>
 #include <unordered_map>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #include <com/sun/star/uno/Any.hxx>
 #include <com/sun/star/uno/Reference.hxx>
 #include <comphelper/stl_types.hxx>
@@ -226,9 +226,9 @@ struct MSFILTER_DLLPUBLIC SvxMSDffImportRec
                     pClientDataBuffer;
     sal_uInt32      nClientDataLen;
     sal_uInt32      nXAlign;
-    boost::optional<sal_uInt32> nXRelTo;
+    o3tl::optional<sal_uInt32> nXRelTo;
     sal_uInt32      nYAlign;
-    boost::optional<sal_uInt32> nYRelTo;
+    o3tl::optional<sal_uInt32> nYRelTo;
     sal_uInt32      nLayoutInTableCell;
     ShapeFlag       nFlags;
     sal_Int32       nDxTextLeft;    ///< distance of text box from surrounding shape
diff --git a/include/filter/msfilter/svdfppt.hxx b/include/filter/msfilter/svdfppt.hxx
index 51bdd1917e35..ec50015bb191 100644
--- a/include/filter/msfilter/svdfppt.hxx
+++ b/include/filter/msfilter/svdfppt.hxx
@@ -25,7 +25,7 @@
 #include <memory>
 #include <vector>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 
 #include <com/sun/star/uno/Reference.hxx>
 #include <editeng/eeitem.hxx>
@@ -491,7 +491,7 @@ struct MSFILTER_DLLPUBLIC PPTFieldEntry
     sal_uInt16          nTextRangeEnd;
     std::unique_ptr<SvxFieldItem> xField1;
     std::unique_ptr<SvxFieldItem> xField2;
-    boost::optional<OUString> xString;
+    o3tl::optional<OUString> xString;
 
     PPTFieldEntry()
         : nPos(0)
@@ -813,7 +813,7 @@ class PPTNumberFormatCreator
                     sal_uInt32 nLevel,
                     TSS_Type nInstance,
                     TSS_Type nInstanceInSheet,
-                    boost::optional< sal_Int16 >& rStartNumbering,
+                    o3tl::optional< sal_Int16 >& rStartNumbering,
                     sal_uInt32 nFontHeight,
                     PPTParagraphObj const * pPara
                 );
@@ -841,7 +841,7 @@ public:
                     SvxNumberFormat& rNumberFormat,
                     PPTParagraphObj* pPara,
                     TSS_Type nInstanceInSheet,
-                    boost::optional< sal_Int16 >& rStartNumbering
+                    o3tl::optional< sal_Int16 >& rStartNumbering
                 );
 };
 
@@ -1177,7 +1177,7 @@ public:
     void                    AppendPortion( PPTPortionObj& rPortion );
     void                    ApplyTo(
                                 SfxItemSet& rSet,
-                                boost::optional< sal_Int16 >& rStartNumbering,
+                                o3tl::optional< sal_Int16 >& rStartNumbering,
                                 SdrPowerPointImport const & rManager,
                                 TSS_Type nInstanceInSheet
                             );
diff --git a/include/o3tl/any.hxx b/include/o3tl/any.hxx
index 141d788e15c4..b4d9e5272fc5 100644
--- a/include/o3tl/any.hxx
+++ b/include/o3tl/any.hxx
@@ -16,7 +16,7 @@
 #include <type_traits>
 #include <utility>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 
 #include <com/sun/star/uno/Any.hxx>
 #include <com/sun/star/uno/RuntimeException.hpp>
@@ -36,37 +36,37 @@ namespace detail {
 struct Void {};
 
 template<typename T> struct Optional { using type = T const *; };
-template<> struct Optional<void> { using type = boost::optional<Void const>; };
-template<> struct Optional<bool> { using type = boost::optional<bool const>; };
+template<> struct Optional<void> { using type = o3tl::optional<Void const>; };
+template<> struct Optional<bool> { using type = o3tl::optional<bool const>; };
 template<> struct Optional<sal_Int8> {
-    using type = boost::optional<sal_Int8 const>;
+    using type = o3tl::optional<sal_Int8 const>;
 };
 template<> struct Optional<sal_Int16> {
-    using type = boost::optional<sal_Int16 const>;
+    using type = o3tl::optional<sal_Int16 const>;
 };
 template<> struct Optional<sal_uInt16> {
-    using type = boost::optional<sal_uInt16 const>;
+    using type = o3tl::optional<sal_uInt16 const>;
 };
 template<> struct Optional<sal_Int32> {
-    using type = boost::optional<sal_Int32 const>;
+    using type = o3tl::optional<sal_Int32 const>;
 };
 template<> struct Optional<sal_uInt32> {
-    using type = boost::optional<sal_uInt32 const>;
+    using type = o3tl::optional<sal_uInt32 const>;
 };
 template<> struct Optional<sal_Int64> {
-    using type = boost::optional<sal_Int64 const>;
+    using type = o3tl::optional<sal_Int64 const>;
 };
 template<> struct Optional<sal_uInt64> {
-    using type = boost::optional<sal_uInt64 const>;
+    using type = o3tl::optional<sal_uInt64 const>;
 };
 template<> struct Optional<float> {
-    using type = boost::optional<float const>;
+    using type = o3tl::optional<float const>;
 };
 template<> struct Optional<double> {
-    using type = boost::optional<double const>;
+    using type = o3tl::optional<double const>;
 };
 template<typename T> struct Optional<css::uno::Reference<T>> {
-    using type = boost::optional<css::uno::Reference<T> const>;
+    using type = o3tl::optional<css::uno::Reference<T> const>;
 };
 template<> struct Optional<css::uno::Reference<css::uno::XInterface>> {
     using type = css::uno::Reference<css::uno::XInterface> const *;
@@ -85,12 +85,12 @@ template<typename T> struct IsUnoSequenceType<cppu::UnoSequenceType<T>>:
     std::true_type
 {};
 
-template<typename T> inline boost::optional<T const> tryGetConverted(
+template<typename T> inline o3tl::optional<T const> tryGetConverted(
     css::uno::Any const & any)
 {
     T v;
     return (any >>= v)
-        ? boost::optional<T const>(std::move(v)) : boost::optional<T const>();
+        ? o3tl::optional<T const>(std::move(v)) : o3tl::optional<T const>();
 }
 
 }
@@ -105,7 +105,7 @@ template<typename T> inline boost::optional<T const> tryGetConverted(
     proxy is positive.  For a positive proxy P representing a value of requested
     type T, for any T other than void, the expression *P yields that value of
     type T.  (Technically, the proxy is either a plain pointer or a
-    boost::optional, depending on whether a plain pointer into the given Any can
+    o3tl::optional, depending on whether a plain pointer into the given Any can
     be returned for the specified type.)
 
     @attention A proxy returned from this function must not outlive the
@@ -124,7 +124,7 @@ template<typename T> inline boost::optional<T const> tryGetConverted(
     @note Ideally this would be a public member function of css::uno::Any (at
     least conditional on LIBO_INTERNAL_ONLY, as it requires C++11).  However, as
     std::optional (which would be needed to implement the proxies) is only
-    available since C++14, we need to use boost::optional for now.  But To not
+    available since C++14, we need to use o3tl::optional for now.  But To not
     make every entity that includes <com/sun/star/uno/Any.hxx> depend on
     boost_headers, keep this here for now.
 
@@ -156,8 +156,8 @@ template<> inline detail::Optional<void>::type tryAccess<void>(
     css::uno::Any const & any)
 {
     return any.hasValue()
-        ? boost::optional<detail::Void const>()
-        : boost::optional<detail::Void const>(detail::Void());
+        ? o3tl::optional<detail::Void const>()
+        : o3tl::optional<detail::Void const>(detail::Void());
 }
 
 template<> inline detail::Optional<bool>::type tryAccess<bool>(
diff --git a/include/o3tl/optional.hxx b/include/o3tl/optional.hxx
new file mode 100644
index 000000000000..6da85698c2d8
--- /dev/null
+++ b/include/o3tl/optional.hxx
@@ -0,0 +1,46 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+// A wrapper selecting either std::optional or boost::optional as a fallback for Xcode < 10.  To be
+// removed once std::optional is available everywhere.
+
+#ifndef INCLUDED_O3TL_OPTIONAL_HXX
+#define INCLUDED_O3TL_OPTIONAL_HXX
+
+#include <sal/config.h>
+
+#if defined __APPLE__ && !__has_include(<optional>)
+
+#include <boost/none.hpp>
+#include <boost/optional.hpp>
+
+namespace o3tl
+{
+using boost::make_optional;
+using boost::optional;
+
+inline constexpr auto nullopt = boost::none;
+}
+
+#else
+
+#include <optional>
+
+namespace o3tl
+{
+using std::make_optional;
+using std::nullopt;
+using std::optional;
+}
+
+#endif
+
+#endif
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */
diff --git a/include/oox/helper/helper.hxx b/include/oox/helper/helper.hxx
index d2077aaaa319..5a83c3780bc8 100644
--- a/include/oox/helper/helper.hxx
+++ b/include/oox/helper/helper.hxx
@@ -154,7 +154,7 @@ inline void setFlag( Type& ornBitField, Type nMask, bool bSet = true )
 }
 
 
-/** Optional value, similar to ::boost::optional<>, with convenience accessors.
+/** Optional value, similar to ::o3tl::optional<>, with convenience accessors.
  */
 template< typename Type >
 class OptValue
diff --git a/include/sax/tools/converter.hxx b/include/sax/tools/converter.hxx
index 967c395433ff..42b769706da0 100644
--- a/include/sax/tools/converter.hxx
+++ b/include/sax/tools/converter.hxx
@@ -22,7 +22,7 @@
 
 #include <sal/config.h>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 
 #include <sax/saxdllapi.h>
 
@@ -196,7 +196,7 @@ public:
                     css::util::Date * pDate,
                     css::util::DateTime & rDateTime,
                     bool & rbDateTime,
-                    boost::optional<sal_Int16> * pTimeZoneOffset,
+                    o3tl::optional<sal_Int16> * pTimeZoneOffset,
                     const OUString & rString );
 
     /** gets the position of the first comma after npos in the string
diff --git a/include/sfx2/dinfdlg.hxx b/include/sfx2/dinfdlg.hxx
index 08be8bb5ea19..b02a3138b6c8 100644
--- a/include/sfx2/dinfdlg.hxx
+++ b/include/sfx2/dinfdlg.hxx
@@ -36,7 +36,7 @@
 
 #include <sfx2/tabdlg.hxx>
 
-#include <boost/optional/optional.hpp>
+#include <o3tl/optional.hxx>
 #include <memory>
 
 namespace com::sun::star::beans { struct PropertyValue; }
@@ -249,7 +249,7 @@ class CustomPropertiesDateField
 private:
     std::unique_ptr<SvtCalendarBox> m_xDateField;
 public:
-    ::boost::optional<sal_Int16> m_TZ;
+    ::o3tl::optional<sal_Int16> m_TZ;
 
     CustomPropertiesDateField(SvtCalendarBox* pDateField);
     void set_visible(bool bVisible) { m_xDateField->set_visible(bVisible); }
diff --git a/include/sfx2/sidebar/SidebarController.hxx b/include/sfx2/sidebar/SidebarController.hxx
index 596382a36888..e65bceb78b6f 100644
--- a/include/sfx2/sidebar/SidebarController.hxx
+++ b/include/sfx2/sidebar/SidebarController.hxx
@@ -36,7 +36,7 @@
 #include <com/sun/star/ui/XContextChangeEventListener.hpp>
 #include <com/sun/star/ui/XSidebar.hpp>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #include <cppuhelper/compbase.hxx>
 #include <cppuhelper/basemutex.hxx>
 
@@ -196,8 +196,8 @@ private:
         mbIsDeckRequestedOpen.  Normally both flags have the same
         value.  A document being read-only can prevent the deck from opening.
     */
-    ::boost::optional<bool> mbIsDeckRequestedOpen;
-    ::boost::optional<bool> mbIsDeckOpen;
+    ::o3tl::optional<bool> mbIsDeckRequestedOpen;
+    ::o3tl::optional<bool> mbIsDeckOpen;
 
     bool mbFloatingDeckClosed;
 
diff --git a/include/svtools/table/tablemodel.hxx b/include/svtools/table/tablemodel.hxx
index 088b9a81783a..8fadf6f10c54 100644
--- a/include/svtools/table/tablemodel.hxx
+++ b/include/svtools/table/tablemodel.hxx
@@ -30,7 +30,7 @@
 
 #include <sal/types.h>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #include <memory>
 #include <vector>
 #include <o3tl/typed_flags_set.hxx>
@@ -365,55 +365,55 @@ namespace svt { namespace table
 
             If this value is not set, a default color from the style settings will be used.
         */
-        virtual ::boost::optional< ::Color >    getLineColor() const = 0;
+        virtual ::o3tl::optional< ::Color >    getLineColor() const = 0;
 
         /** returns the color to be used for rendering the header background.
 
             If this value is not set, a default color from the style settings will be used.
         */
-        virtual ::boost::optional< ::Color >    getHeaderBackgroundColor() const = 0;
+        virtual ::o3tl::optional< ::Color >    getHeaderBackgroundColor() const = 0;
 
         /** returns the color to be used for rendering the header text.
 
             If this value is not set, a default color from the style settings will be used.
         */
-        virtual ::boost::optional< ::Color >    getHeaderTextColor() const = 0;
+        virtual ::o3tl::optional< ::Color >    getHeaderTextColor() const = 0;
 
         /** returns the color to be used for the background of selected cells, when the control has the focus
 
             If this value is not set, a default color from the style settings will be used.
         */
-        virtual ::boost::optional< ::Color >    getActiveSelectionBackColor() const = 0;
+        virtual ::o3tl::optional< ::Color >    getActiveSelectionBackColor() const = 0;
 
         /** returns the color to be used for the background of selected cells, when the control does not have the focus
 
             If this value is not set, a default color from the style settings will be used.
         */
-        virtual ::boost::optional< ::Color >    getInactiveSelectionBackColor() const = 0;
+        virtual ::o3tl::optional< ::Color >    getInactiveSelectionBackColor() const = 0;
 
         /** returns the color to be used for the text of selected cells, when the control has the focus
 
             If this value is not set, a default color from the style settings will be used.
         */
-        virtual ::boost::optional< ::Color >    getActiveSelectionTextColor() const = 0;
+        virtual ::o3tl::optional< ::Color >    getActiveSelectionTextColor() const = 0;
 
         /** returns the color to be used for the text of selected cells, when the control does not have the focus
 
             If this value is not set, a default color from the style settings will be used.
         */
-        virtual ::boost::optional< ::Color >    getInactiveSelectionTextColor() const = 0;
+        virtual ::o3tl::optional< ::Color >    getInactiveSelectionTextColor() const = 0;
 
         /** returns the color to be used for rendering cell texts.
 
             If this value is not set, a default color from the style settings will be used.
         */
-        virtual ::boost::optional< ::Color >    getTextColor() const = 0;
+        virtual ::o3tl::optional< ::Color >    getTextColor() const = 0;
 
         /** returns the color to be used for text lines (underline, strikethrough) when rendering cell text.
 
             If this value is not set, a default color from the style settings will be used.
         */
-        virtual ::boost::optional< ::Color >    getTextLineColor() const = 0;
+        virtual ::o3tl::optional< ::Color >    getTextLineColor() const = 0;
 
         /** returns the colors to be used for the row backgrounds.
 
@@ -426,7 +426,7 @@ namespace svt { namespace table
             If value is a non-empty sequence, then rows will have the background colors as specified in the sequence,
             in alternating order.
         */
-        virtual ::boost::optional< ::std::vector< ::Color > >
+        virtual ::o3tl::optional< ::std::vector< ::Color > >
                                                 getRowBackgroundColors() const = 0;
 
         /** determines the vertical alignment of content within a cell
diff --git a/include/svx/ClassificationEditView.hxx b/include/svx/ClassificationEditView.hxx
index fbea139b9792..8c30518b1816 100644
--- a/include/svx/ClassificationEditView.hxx
+++ b/include/svx/ClassificationEditView.hxx
@@ -24,7 +24,7 @@ class ClassificationEditEngine final : public EditEngine
 public:
     ClassificationEditEngine(SfxItemPool* pItemPool);
 
-    virtual OUString CalcFieldValue(const SvxFieldItem& rField, sal_Int32 nPara, sal_Int32 nPos, boost::optional<Color>& rTxtColor, boost::optional<Color>& rFldColor) override;
+    virtual OUString CalcFieldValue(const SvxFieldItem& rField, sal_Int32 nPara, sal_Int32 nPos, o3tl::optional<Color>& rTxtColor, o3tl::optional<Color>& rFldColor) override;
 };
 
 class ClassificationEditView final : public WeldEditView
diff --git a/include/svx/svdomeas.hxx b/include/svx/svdomeas.hxx
index cce1df59819a..bb182c6e2f67 100644
--- a/include/svx/svdomeas.hxx
+++ b/include/svx/svdomeas.hxx
@@ -140,7 +140,7 @@ public:
     virtual OutlinerParaObject* GetOutlinerParaObject() const override;
 
     virtual bool CalcFieldValue(const SvxFieldItem& rField, sal_Int32 nPara, sal_uInt16 nPos,
-        bool bEdit, boost::optional<Color>& rpTxtColor, boost::optional<Color>& rpFldColor, OUString& rRet) const override;
+        bool bEdit, o3tl::optional<Color>& rpTxtColor, o3tl::optional<Color>& rpFldColor, OUString& rRet) const override;
 
     // #i97878#
     virtual bool TRGetBaseGeometry(basegfx::B2DHomMatrix& rMatrix, basegfx::B2DPolyPolygon& rPolyPolygon) const override;
diff --git a/include/svx/svdotext.hxx b/include/svx/svdotext.hxx
index d49f1221dc98..ccb6686e883d 100644
--- a/include/svx/svdotext.hxx
+++ b/include/svx/svdotext.hxx
@@ -497,7 +497,7 @@ public:
     virtual void NbcReformatText() override;
 
     virtual bool CalcFieldValue(const SvxFieldItem& rField, sal_Int32 nPara, sal_uInt16 nPos,
-        bool bEdit, boost::optional<Color>& rpTxtColor, boost::optional<Color>& rpFldColor, OUString& rRet) const;
+        bool bEdit, o3tl::optional<Color>& rpTxtColor, o3tl::optional<Color>& rpFldColor, OUString& rRet) const;
 
     virtual SdrObjectUniquePtr DoConvertToPolyObj(bool bBezier, bool bAddText) const override;
 
diff --git a/include/svx/svdoutl.hxx b/include/svx/svdoutl.hxx
index 7655dee739b7..eb1b51523f53 100644
--- a/include/svx/svdoutl.hxx
+++ b/include/svx/svdoutl.hxx
@@ -43,7 +43,7 @@ public:
     void setVisualizedPage(const SdrPage* pPage) { if(pPage != mpVisualizedPage) mpVisualizedPage = pPage; }
     const SdrPage* getVisualizedPage() const { return mpVisualizedPage; }
 
-    virtual OUString CalcFieldValue(const SvxFieldItem& rField, sal_Int32 nPara, sal_Int32 nPos, boost::optional<Color>& rpTxtColor, boost::optional<Color>& rpFldColor) override;
+    virtual OUString CalcFieldValue(const SvxFieldItem& rField, sal_Int32 nPara, sal_Int32 nPos, o3tl::optional<Color>& rpTxtColor, o3tl::optional<Color>& rpFldColor) override;
 
     bool hasEditViewCallbacks() const;
 };
diff --git a/include/toolkit/controls/unocontrols.hxx b/include/toolkit/controls/unocontrols.hxx
index 5ea17a412915..6bc0fafb570a 100644
--- a/include/toolkit/controls/unocontrols.hxx
+++ b/include/toolkit/controls/unocontrols.hxx
@@ -54,7 +54,7 @@
 #include <memory>
 #include <vector>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 
 namespace com { namespace sun { namespace star { namespace graphic { class XGraphic; } } } }
 namespace com { namespace sun { namespace star { namespace graphic { class XGraphicObject; } } } }
@@ -804,15 +804,15 @@ protected:
 private:
     void    impl_notifyItemListEvent_nolck(
                 const sal_Int32 i_nItemPosition,
-                const ::boost::optional< OUString >& i_rItemText,
-                const ::boost::optional< OUString >& i_rItemImageURL,
+                const ::o3tl::optional< OUString >& i_rItemText,
+                const ::o3tl::optional< OUString >& i_rItemImageURL,
                 void ( SAL_CALL css::awt::XItemListListener::*NotificationMethod )( const css::awt::ItemListEvent& )
             );
 
     void    impl_handleInsert(
                 const sal_Int32 i_nItemPosition,
-                const ::boost::optional< OUString >& i_rItemText,
-                const ::boost::optional< OUString >& i_rItemImageURL,
+                const ::o3tl::optional< OUString >& i_rItemText,
+                const ::o3tl::optional< OUString >& i_rItemImageURL,
                 ::osl::ClearableMutexGuard& i_rClearBeforeNotify
             );
 
@@ -823,8 +823,8 @@ private:
 
     void    impl_handleModify(
                 const sal_Int32 i_nItemPosition,
-                const ::boost::optional< OUString >& i_rItemText,
-                const ::boost::optional< OUString >& i_rItemImageURL,
+                const ::o3tl::optional< OUString >& i_rItemText,
+                const ::o3tl::optional< OUString >& i_rItemImageURL,
                 ::osl::ClearableMutexGuard& i_rClearBeforeNotify
             );
 
diff --git a/include/unotools/historyoptions.hxx b/include/unotools/historyoptions.hxx
index 87ce484533c3..b723dc9326b7 100644
--- a/include/unotools/historyoptions.hxx
+++ b/include/unotools/historyoptions.hxx
@@ -27,7 +27,7 @@
 #include <unotools/options.hxx>
 #include <memory>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 
 namespace com { namespace sun { namespace star { namespace beans { struct PropertyValue; } } } }
 
@@ -86,7 +86,7 @@ public:
     */
     void AppendItem(EHistoryType eHistory,
             const OUString& sURL, const OUString& sFilter, const OUString& sTitle,
-            const boost::optional<OUString>& sThumbnail);
+            const o3tl::optional<OUString>& sThumbnail);
 
     /** Delete item from the specified list.
     */
diff --git a/include/vcl/fontcapabilities.hxx b/include/vcl/fontcapabilities.hxx
index 51aa13e58ade..539dd2710d0c 100644
--- a/include/vcl/fontcapabilities.hxx
+++ b/include/vcl/fontcapabilities.hxx
@@ -10,7 +10,7 @@
 #ifndef INCLUDED_VCL_FONTCAPABILITIES_HXX
 #define INCLUDED_VCL_FONTCAPABILITIES_HXX
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #include <bitset>
 
 //See OS/2 table, i.e. http://www.microsoft.com/typography/otspec/os2.htm#ur
@@ -193,8 +193,8 @@ namespace vcl
 
     struct FontCapabilities
     {
-        boost::optional<std::bitset<UnicodeCoverage::MAX_UC_ENUM>> oUnicodeRange;
-        boost::optional<std::bitset<CodePageCoverage::MAX_CP_ENUM>> oCodePageRange;
+        o3tl::optional<std::bitset<UnicodeCoverage::MAX_UC_ENUM>> oUnicodeRange;
+        o3tl::optional<std::bitset<CodePageCoverage::MAX_CP_ENUM>> oCodePageRange;
     };
 }
 
diff --git a/include/vcl/outdevstate.hxx b/include/vcl/outdevstate.hxx
index 493855248db0..5f0b12d41d86 100644
--- a/include/vcl/outdevstate.hxx
+++ b/include/vcl/outdevstate.hxx
@@ -28,7 +28,7 @@
 #include <tools/fontenum.hxx>
 #include <o3tl/typed_flags_set.hxx>
 #include <memory>
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #include <i18nlangtag/lang.h>
 
 namespace vcl { class Font; }
@@ -81,17 +81,17 @@ struct OutDevState
     OutDevState(OutDevState&&);
     ~OutDevState();
 
-    boost::optional<MapMode>        mpMapMode;
+    o3tl::optional<MapMode>        mpMapMode;
     bool            mbMapActive;
     std::unique_ptr<vcl::Region>    mpClipRegion;
-    boost::optional<Color>          mpLineColor;
-    boost::optional<Color>          mpFillColor;
+    o3tl::optional<Color>          mpLineColor;
+    o3tl::optional<Color>          mpFillColor;
     std::unique_ptr<vcl::Font>      mpFont;
-    boost::optional<Color>          mpTextColor;
-    boost::optional<Color>          mpTextFillColor;
-    boost::optional<Color>          mpTextLineColor;
-    boost::optional<Color>          mpOverlineColor;
-    boost::optional<Point>          mpRefPoint;
+    o3tl::optional<Color>          mpTextColor;
+    o3tl::optional<Color>          mpTextFillColor;
+    o3tl::optional<Color>          mpTextLineColor;
+    o3tl::optional<Color>          mpOverlineColor;
+    o3tl::optional<Point>          mpRefPoint;
     TextAlign       meTextAlign;
     RasterOp        meRasterOp;
     ComplexTextLayoutFlags  mnTextLayoutMode;
diff --git a/include/vcl/settings.hxx b/include/vcl/settings.hxx
index 1f879b188c18..a45e0e685633 100644
--- a/include/vcl/settings.hxx
+++ b/include/vcl/settings.hxx
@@ -29,7 +29,7 @@
 #include <memory>
 #include <vector>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 
 class BitmapEx;
 class LanguageTag;
@@ -549,7 +549,7 @@ public:
 
     BitmapEx const &                GetPersonaFooter() const;
 
-    const boost::optional<Color>&   GetPersonaMenuBarTextColor() const;
+    const o3tl::optional<Color>&   GetPersonaMenuBarTextColor() const;
 
     // global switch to allow EdgeBlenging; currently possible for ValueSet and ListBox
     // when activated there using Get/SetEdgeBlending; default is true
diff --git a/include/vcl/threadex.hxx b/include/vcl/threadex.hxx
index 05d0bada3f58..ceb3354556a8 100644
--- a/include/vcl/threadex.hxx
+++ b/include/vcl/threadex.hxx
@@ -24,7 +24,7 @@
 #include <tools/link.hxx>
 #include <vcl/dllapi.h>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #include <memory>
 
 namespace vcl
@@ -84,9 +84,9 @@ private:
 #else
     FuncT const m_func;
 #endif
-    // using boost::optional here omits the need that ResultT is default
+    // using o3tl::optional here omits the need that ResultT is default
     // constructable:
-    ::boost::optional<ResultT> m_result;
+    ::o3tl::optional<ResultT> m_result;
 };
 
 template <typename FuncT>
diff --git a/include/vcl/treelistentry.hxx b/include/vcl/treelistentry.hxx
index 71c8e8229f11..deb733b7bf9a 100644
--- a/include/vcl/treelistentry.hxx
+++ b/include/vcl/treelistentry.hxx
@@ -27,7 +27,7 @@
 #include <vcl/treelistentries.hxx>
 #include <o3tl/typed_flags_set.hxx>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #include <vector>
 #include <memory>
 
@@ -64,7 +64,7 @@ class VCL_DLLPUBLIC SvTreeListEntry
     void*               pUserData;
     SvTLEntryFlags      nEntryFlags;
     Color               maBackColor;
-    boost::optional<Color> mxTextColor;
+    o3tl::optional<Color> mxTextColor;
 
 private:
     void ClearChildren();
@@ -112,8 +112,8 @@ public:
     void SetBackColor( const Color& rColor ) { maBackColor = rColor; }
     const Color& GetBackColor() const { return maBackColor; }
 
-    void SetTextColor( boost::optional<Color> xColor ) { mxTextColor = xColor; }
-    boost::optional<Color> const & GetTextColor() const { return mxTextColor; }
+    void SetTextColor( o3tl::optional<Color> xColor ) { mxTextColor = xColor; }
+    o3tl::optional<Color> const & GetTextColor() const { return mxTextColor; }
 
     SvTreeListEntry* GetParent() const { return pParent; }