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>

11 files changed, 18 insertions, 18 deletions

diff --git a/svx/inc/pch/precompiled_svx.hxx b/svx/inc/pch/precompiled_svx.hxx
index 0de6708d0827..3a99ad7ed9b3 100644
--- a/svx/inc/pch/precompiled_svx.hxx
+++ b/svx/inc/pch/precompiled_svx.hxx
@@ -41,7 +41,7 @@
 #include <unordered_map>
 #include <utility>
 #include <vector>
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #include <boost/property_tree/ptree.hpp>
 #endif // PCH_LEVEL >= 1
 #if PCH_LEVEL >= 2
diff --git a/svx/inc/pch/precompiled_svxcore.hxx b/svx/inc/pch/precompiled_svxcore.hxx
index ea9506e07fb9..a03b6f300169 100644
--- a/svx/inc/pch/precompiled_svxcore.hxx
+++ b/svx/inc/pch/precompiled_svxcore.hxx
@@ -49,7 +49,7 @@
 #include <unordered_map>
 #include <utility>
 #include <vector>
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #endif // PCH_LEVEL >= 1
 #if PCH_LEVEL >= 2
 #include <osl/diagnose.h>
diff --git a/svx/source/accessibility/AccessibleEmptyEditSource.cxx b/svx/source/accessibility/AccessibleEmptyEditSource.cxx
index a0a31d959183..297315a32bb7 100644
--- a/svx/source/accessibility/AccessibleEmptyEditSource.cxx
+++ b/svx/source/accessibility/AccessibleEmptyEditSource.cxx
@@ -121,7 +121,7 @@ namespace accessibility
         //XTextCopy
         void        CopyText(const SvxTextForwarder& ) override {}
 
-        OUString    CalcFieldValue( const SvxFieldItem& /*rField*/, sal_Int32 /*nPara*/, sal_Int32 /*nPos*/, boost::optional<Color>& /*rpTxtColor*/, boost::optional<Color>& /*rpFldColor*/ ) override
+        OUString    CalcFieldValue( const SvxFieldItem& /*rField*/, sal_Int32 /*nPara*/, sal_Int32 /*nPos*/, o3tl::optional<Color>& /*rpTxtColor*/, o3tl::optional<Color>& /*rpFldColor*/ ) override
         {
             return  OUString();
         }
diff --git a/svx/source/dialog/ClassificationEditView.cxx b/svx/source/dialog/ClassificationEditView.cxx
index bc2266626c35..6eba6e6f12d7 100644
--- a/svx/source/dialog/ClassificationEditView.cxx
+++ b/svx/source/dialog/ClassificationEditView.cxx
@@ -30,7 +30,7 @@ ClassificationEditEngine::ClassificationEditEngine(SfxItemPool* pItemPool)
 {}
 
 OUString ClassificationEditEngine::CalcFieldValue(const SvxFieldItem& rField, sal_Int32 /*nPara*/,
-                                                  sal_Int32 /*nPos*/, boost::optional<Color>& /*rTxtColor*/, boost::optional<Color>& /*rFldColor*/)
+                                                  sal_Int32 /*nPos*/, o3tl::optional<Color>& /*rTxtColor*/, o3tl::optional<Color>& /*rFldColor*/)
 {
     OUString aString;
     const ClassificationField* pClassificationField = dynamic_cast<const ClassificationField*>(rField.GetField());
diff --git a/svx/source/dialog/weldeditview.cxx b/svx/source/dialog/weldeditview.cxx
index 0d0173fc0be5..222a3db5747b 100644
--- a/svx/source/dialog/weldeditview.cxx
+++ b/svx/source/dialog/weldeditview.cxx
@@ -241,8 +241,8 @@ 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;
+                                    o3tl::optional<Color>& rpTxtColor,
+                                    o3tl::optional<Color>& rpFldColor) override;
     virtual void FieldClicked(const SvxFieldItem&) override;
     virtual bool IsValid() const override;
 
@@ -905,8 +905,8 @@ bool WeldTextForwarder::IsValid() const
 }
 
 OUString WeldTextForwarder::CalcFieldValue(const SvxFieldItem& rField, sal_Int32 nPara,
-                                           sal_Int32 nPos, boost::optional<Color>& rpTxtColor,
-                                           boost::optional<Color>& rpFldColor)
+                                           sal_Int32 nPos, o3tl::optional<Color>& rpTxtColor,
+                                           o3tl::optional<Color>& rpFldColor)
 {
     EditEngine* pEditEngine = m_rEditAcc.GetEditEngine();
     return pEditEngine ? pEditEngine->CalcFieldValue(rField, nPara, nPos, rpTxtColor, rpFldColor)
diff --git a/svx/source/form/fmmodel.cxx b/svx/source/form/fmmodel.cxx
index 3791cb7a77d7..5942abfa6454 100644
--- a/svx/source/form/fmmodel.cxx
+++ b/svx/source/form/fmmodel.cxx
@@ -28,7 +28,7 @@
 
 #include <sfx2/objsh.hxx>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 
 using ::com::sun::star::uno::Reference;
 using ::com::sun::star::container::XNameContainer;
@@ -39,7 +39,7 @@ struct FmFormModelImplData
 {
     rtl::Reference<FmXUndoEnvironment>  mxUndoEnv;
     bool                bOpenInDesignIsDefaulted;
-    boost::optional<bool> aControlsUseRefDevice;
+    o3tl::optional<bool> aControlsUseRefDevice;
 
     FmFormModelImplData()
         :bOpenInDesignIsDefaulted( true )
diff --git a/svx/source/svdraw/svdedxv.cxx b/svx/source/svdraw/svdedxv.cxx
index bafc02dc27db..f6861bdadee6 100644
--- a/svx/source/svdraw/svdedxv.cxx
+++ b/svx/source/svdraw/svdedxv.cxx
@@ -1012,8 +1012,8 @@ IMPL_LINK(SdrObjEditView, ImpOutlinerCalcFieldValueHdl, EditFieldInfo*, pFI, voi
     SdrTextObj* pTextObj = mxTextEditObj.get();
     if (pTextObj != nullptr)
     {
-        boost::optional<Color> pTxtCol;
-        boost::optional<Color> pFldCol;
+        o3tl::optional<Color> pTxtCol;
+        o3tl::optional<Color> pFldCol;
         bOk = pTextObj->CalcFieldValue(pFI->GetField(), pFI->GetPara(), pFI->GetPos(), true,
                                        pTxtCol, pFldCol, rStr);
         if (bOk)
diff --git a/svx/source/svdraw/svdobj.cxx b/svx/source/svdraw/svdobj.cxx
index 3758426b974a..28fb05eae8c2 100644
--- a/svx/source/svdraw/svdobj.cxx
+++ b/svx/source/svdraw/svdobj.cxx
@@ -138,7 +138,7 @@
 
 #include <unordered_set>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #include <libxml/xmlwriter.h>
 #include <memory>
 
@@ -207,9 +207,9 @@ struct SdrObject::Impl
 {
     sdr::ObjectUserVector maObjectUsers;
 
-    boost::optional<double> mnRelativeWidth;
+    o3tl::optional<double> mnRelativeWidth;
     sal_Int16               meRelativeWidthRelation;
-    boost::optional<double> mnRelativeHeight;
+    o3tl::optional<double> mnRelativeHeight;
     sal_Int16               meRelativeHeightRelation;
 
     std::shared_ptr<DiagramDataInterface> mpDiagramData;
diff --git a/svx/source/svdraw/svdomeas.cxx b/svx/source/svdraw/svdomeas.cxx
index ca047cde59af..e950dc8f14e3 100644
--- a/svx/source/svdraw/svdomeas.cxx
+++ b/svx/source/svdraw/svdomeas.cxx
@@ -550,7 +550,7 @@ basegfx::B2DPolyPolygon SdrMeasureObj::ImpCalcXPoly(const ImpMeasurePoly& rPol)
 
 bool SdrMeasureObj::CalcFieldValue(const SvxFieldItem& rField, sal_Int32 nPara, sal_uInt16 nPos,
     bool bEdit,
-    boost::optional<Color>& rpTxtColor, boost::optional<Color>& rpFldColor, OUString& rRet) const
+    o3tl::optional<Color>& rpTxtColor, o3tl::optional<Color>& rpFldColor, OUString& rRet) const
 {
     const SvxFieldData* pField=rField.GetField();
     const SdrMeasureField* pMeasureField=dynamic_cast<const SdrMeasureField*>( pField );
diff --git a/svx/source/svdraw/svdotxfl.cxx b/svx/source/svdraw/svdotxfl.cxx
index c8e82711b6a3..11fe15d6eedd 100644
--- a/svx/source/svdraw/svdotxfl.cxx
+++ b/svx/source/svdraw/svdotxfl.cxx
@@ -22,7 +22,7 @@
 #include <svx/svdotext.hxx>
 
 bool SdrTextObj::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
 {
     return false;
 }
diff --git a/svx/source/svdraw/svdoutl.cxx b/svx/source/svdraw/svdoutl.cxx
index 0387afaa5ec9..31fb093bedb2 100644
--- a/svx/source/svdraw/svdoutl.cxx
+++ b/svx/source/svdraw/svdoutl.cxx
@@ -72,7 +72,7 @@ void SdrOutliner::SetTextObjNoInit( const SdrTextObj* pObj )
 }
 
 OUString SdrOutliner::CalcFieldValue(const SvxFieldItem& rField, sal_Int32 nPara, sal_Int32 nPos,
-                                     boost::optional<Color>& rpTxtColor, boost::optional<Color>& rpFldColor)
+                                     o3tl::optional<Color>& rpTxtColor, o3tl::optional<Color>& rpFldColor)
 {
     bool bOk = false;
     OUString aRet;