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>

4 files changed, 19 insertions, 19 deletions

diff --git a/oox/inc/drawingml/table/tablestylepart.hxx b/oox/inc/drawingml/table/tablestylepart.hxx
index 2a03339962ca..056b79b393f1 100644
--- a/oox/inc/drawingml/table/tablestylepart.hxx
+++ b/oox/inc/drawingml/table/tablestylepart.hxx
@@ -21,7 +21,7 @@
 #define INCLUDED_OOX_DRAWINGML_TABLE_TABLESTYLEPART_HXX
 
 #include <rtl/ustring.hxx>
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #include <oox/drawingml/color.hxx>
 #include <drawingml/textfont.hxx>
 #include <oox/drawingml/shape.hxx>
@@ -40,8 +40,8 @@ public:
     TableStylePart();
 
     ::oox::drawingml::Color&            getTextColor(){ return maTextColor; }
-    ::boost::optional< bool >&          getTextBoldStyle(){ return maTextBoldStyle; }
-    ::boost::optional< bool >&          getTextItalicStyle(){ return maTextItalicStyle; }
+    ::o3tl::optional< bool >&          getTextBoldStyle(){ return maTextBoldStyle; }
+    ::o3tl::optional< bool >&          getTextItalicStyle(){ return maTextItalicStyle; }
     ::oox::drawingml::TextFont&         getAsianFont(){ return maAsianFont; }
     ::oox::drawingml::TextFont&         getComplexFont(){ return maComplexFont; }
     ::oox::drawingml::TextFont&         getSymbolFont(){ return maSymbolFont; }
@@ -55,8 +55,8 @@ public:
 private:
 
     ::oox::drawingml::Color             maTextColor;
-    ::boost::optional< bool >           maTextBoldStyle;
-    ::boost::optional< bool >           maTextItalicStyle;
+    ::o3tl::optional< bool >           maTextBoldStyle;
+    ::o3tl::optional< bool >           maTextItalicStyle;
     ::oox::drawingml::TextFont          maAsianFont;
     ::oox::drawingml::TextFont          maComplexFont;
     ::oox::drawingml::TextFont          maSymbolFont;
diff --git a/oox/inc/drawingml/textbodyproperties.hxx b/oox/inc/drawingml/textbodyproperties.hxx
index 785f117568a9..4c378cf094a0 100644
--- a/oox/inc/drawingml/textbodyproperties.hxx
+++ b/oox/inc/drawingml/textbodyproperties.hxx
@@ -23,7 +23,7 @@
 #include <com/sun/star/drawing/TextVerticalAdjust.hpp>
 #include <oox/helper/helper.hxx>
 #include <oox/helper/propertymap.hxx>
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 
 namespace oox {
 namespace drawingml {
@@ -35,11 +35,11 @@ struct TextBodyProperties
     OptValue< sal_Int32 >                           moRotation;
     bool                                            mbAnchorCtr;
     OptValue< sal_Int32 >                           moVert;
-    boost::optional< sal_Int32 >                    moInsets[4];
-    boost::optional< sal_Int32 >                    moTextOffUpper;
-    boost::optional< sal_Int32 >                    moTextOffLeft;
-    boost::optional< sal_Int32 >                    moTextOffLower;
-    boost::optional< sal_Int32 >                    moTextOffRight;
+    o3tl::optional< sal_Int32 >                    moInsets[4];
+    o3tl::optional< sal_Int32 >                    moTextOffUpper;
+    o3tl::optional< sal_Int32 >                    moTextOffLeft;
+    o3tl::optional< sal_Int32 >                    moTextOffLower;
+    o3tl::optional< sal_Int32 >                    moTextOffRight;
     css::drawing::TextVerticalAdjust                meVA;
     OUString                                        msPrst;
     /// Number of requested columns.
diff --git a/oox/inc/drawingml/textparagraphproperties.hxx b/oox/inc/drawingml/textparagraphproperties.hxx
index 5b8093bab391..6b9d93ccdf78 100644
--- a/oox/inc/drawingml/textparagraphproperties.hxx
+++ b/oox/inc/drawingml/textparagraphproperties.hxx
@@ -27,7 +27,7 @@
 #include <com/sun/star/style/ParagraphAdjust.hpp>
 #include <drawingml/textfont.hxx>
 #include <drawingml/textspacing.hxx>
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 
 namespace com { namespace sun { namespace star {
     namespace graphic { class XGraphic; }
@@ -90,10 +90,10 @@ public:
 
     TextSpacing&                        getParaTopMargin() { return maParaTopMargin; }
     TextSpacing&                        getParaBottomMargin() { return maParaBottomMargin; }
-    boost::optional< sal_Int32 >&       getParaLeftMargin(){ return moParaLeftMargin; }
-    boost::optional< sal_Int32 >&       getFirstLineIndentation(){ return moFirstLineIndentation; }
+    o3tl::optional< sal_Int32 >&       getParaLeftMargin(){ return moParaLeftMargin; }
+    o3tl::optional< sal_Int32 >&       getFirstLineIndentation(){ return moFirstLineIndentation; }
 
-    boost::optional< css::style::ParagraphAdjust >&       getParaAdjust() { return moParaAdjust; }
+    o3tl::optional< css::style::ParagraphAdjust >&       getParaAdjust() { return moParaAdjust; }
     void                                setParaAdjust( css::style::ParagraphAdjust nParaAdjust ) { moParaAdjust = nParaAdjust; }
 
     TextSpacing&                        getLineSpacing() { return maLineSpacing; }
@@ -124,9 +124,9 @@ protected:
     BulletList                      maBulletList;
     TextSpacing                     maParaTopMargin;
     TextSpacing                     maParaBottomMargin;
-    boost::optional< sal_Int32 >    moParaLeftMargin;
-    boost::optional< sal_Int32 >    moFirstLineIndentation;
-    boost::optional< css::style::ParagraphAdjust >    moParaAdjust;
+    o3tl::optional< sal_Int32 >    moParaLeftMargin;
+    o3tl::optional< sal_Int32 >    moFirstLineIndentation;
+    o3tl::optional< css::style::ParagraphAdjust >    moParaAdjust;
     sal_Int16                       mnLevel;
     TextSpacing                     maLineSpacing;
 };
diff --git a/oox/inc/pch/precompiled_oox.hxx b/oox/inc/pch/precompiled_oox.hxx
index 17c38625bf2d..e261a0a46118 100644
--- a/oox/inc/pch/precompiled_oox.hxx
+++ b/oox/inc/pch/precompiled_oox.hxx
@@ -40,7 +40,7 @@
 #include <utility>
 #include <vector>
 #include <boost/algorithm/string.hpp>
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #endif // PCH_LEVEL >= 1
 #if PCH_LEVEL >= 2
 #include <osl/diagnose.h>