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>

19 files changed, 46 insertions, 46 deletions

diff --git a/vcl/inc/bitmapwriteaccess.hxx b/vcl/inc/bitmapwriteaccess.hxx
index 02ca3f983300..0cb7fbf3a653 100644
--- a/vcl/inc/bitmapwriteaccess.hxx
+++ b/vcl/inc/bitmapwriteaccess.hxx
@@ -14,7 +14,7 @@
 #include <vcl/alpha.hxx>
 #include <vcl/bitmap.hxx>
 #include <vcl/bitmapaccess.hxx>
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 
 typedef vcl::ScopedBitmapAccess<BitmapWriteAccess, Bitmap, &Bitmap::AcquireWriteAccess>
     BitmapScopedWriteAccess;
@@ -83,8 +83,8 @@ public:
     void DrawRect(const tools::Rectangle& rRect);
 
 private:
-    boost::optional<BitmapColor> mpLineColor;
-    boost::optional<BitmapColor> mpFillColor;
+    o3tl::optional<BitmapColor> mpLineColor;
+    o3tl::optional<BitmapColor> mpFillColor;
 
     BitmapWriteAccess() = delete;
     BitmapWriteAccess(const BitmapWriteAccess&) = delete;
diff --git a/vcl/inc/fontinstance.hxx b/vcl/inc/fontinstance.hxx
index b4d7da663090..03663e025b6d 100644
--- a/vcl/inc/fontinstance.hxx
+++ b/vcl/inc/fontinstance.hxx
@@ -30,7 +30,7 @@
 #include <tools/fontenum.hxx>
 #include <vcl/glyphitem.hxx>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #include <unordered_map>
 #include <memory>
 
@@ -103,7 +103,7 @@ private:
     hb_font_t* m_pHbFont;
     double m_nAveWidthFactor;
     rtl::Reference<PhysicalFontFace> m_pFontFace;
-    boost::optional<bool> m_xbIsGraphiteFont;
+    o3tl::optional<bool> m_xbIsGraphiteFont;
 };
 
 inline hb_font_t* LogicalFontInstance::GetHbFont()
diff --git a/vcl/inc/pch/precompiled_vcl.hxx b/vcl/inc/pch/precompiled_vcl.hxx
index aad967c13739..d1b9eaf54270 100644
--- a/vcl/inc/pch/precompiled_vcl.hxx
+++ b/vcl/inc/pch/precompiled_vcl.hxx
@@ -50,7 +50,7 @@
 #include <boost/functional/hash.hpp>
 #include <boost/math/special_functions/sinc.hpp>
 #include <boost/multi_array.hpp>
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #endif // PCH_LEVEL >= 1
 #if PCH_LEVEL >= 2
 #include <osl/conditn.hxx>
diff --git a/vcl/inc/sft.hxx b/vcl/inc/sft.hxx
index 8c7e4aaa8711..985ad5623e50 100644
--- a/vcl/inc/sft.hxx
+++ b/vcl/inc/sft.hxx
@@ -489,8 +489,8 @@ constexpr sal_uInt32 T_CFF  = 0x43464620;
 #endif
 
     bool VCL_DLLPUBLIC getTTCoverage(
-        boost::optional<std::bitset<UnicodeCoverage::MAX_UC_ENUM>> & rUnicodeCoverage,
-        boost::optional<std::bitset<CodePageCoverage::MAX_CP_ENUM>> & rCodePageCoverage,
+        o3tl::optional<std::bitset<UnicodeCoverage::MAX_UC_ENUM>> & rUnicodeCoverage,
+        o3tl::optional<std::bitset<CodePageCoverage::MAX_CP_ENUM>> & rCodePageCoverage,
         const unsigned char* pTable, size_t nLength);
 
 /**
diff --git a/vcl/inc/svdata.hxx b/vcl/inc/svdata.hxx
index 181082782e06..f95b6136e6d8 100644
--- a/vcl/inc/svdata.hxx
+++ b/vcl/inc/svdata.hxx
@@ -135,10 +135,10 @@ struct ImplSVAppData
     SVAppKeyListeners       maKeyListeners;       // listeners for key events only (eg, extended toolkit)
     std::vector<ImplPostEventPair> maPostedEventList;
     ImplAccelManager*       mpAccelMgr;           // Accelerator Manager
-    boost::optional<OUString> mxAppName;            // Application name
-    boost::optional<OUString> mxAppFileName;        // Abs. Application FileName
-    boost::optional<OUString> mxDisplayName;        // Application Display Name
-    boost::optional<OUString> mxToolkitName;        // Toolkit Name
+    o3tl::optional<OUString> mxAppName;            // Application name
+    o3tl::optional<OUString> mxAppFileName;        // Abs. Application FileName
+    o3tl::optional<OUString> mxDisplayName;        // Application Display Name
+    o3tl::optional<OUString> mxToolkitName;        // Toolkit Name
     Help*                   mpHelp = nullptr;               // Application help
     VclPtr<PopupMenu>       mpActivePopupMenu;              // Actives Popup-Menu (in Execute)
     VclPtr<ImplWheelWindow> mpWheelWindow;                  // WheelWindow
diff --git a/vcl/inc/unx/screensaverinhibitor.hxx b/vcl/inc/unx/screensaverinhibitor.hxx
index 7100a8877399..fcc6f4917fa1 100644
--- a/vcl/inc/unx/screensaverinhibitor.hxx
+++ b/vcl/inc/unx/screensaverinhibitor.hxx
@@ -16,24 +16,24 @@
 #include <rtl/ustring.hxx>
 #include <vcl/dllapi.h>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 
 class VCL_PLUGIN_PUBLIC ScreenSaverInhibitor
 {
 public:
     void inhibit( bool bInhibit, const OUString& sReason,
-                  bool bIsX11, const boost::optional<unsigned int>& xid, boost::optional<Display*> pDisplay );
+                  bool bIsX11, const o3tl::optional<unsigned int>& xid, o3tl::optional<Display*> pDisplay );
 
 private:
     // These are all used as guint, however this header may be included
     // in kde/tde/etc backends, where we would ideally avoid having
     // any glib dependencies, hence the direct use of unsigned int.
-    boost::optional<unsigned int> mnFDOCookie; // FDO ScreenSaver Inhibit
-    boost::optional<unsigned int> mnFDOPMCookie; // FDO PowerManagement Inhibit
-    boost::optional<unsigned int> mnGSMCookie;
-    boost::optional<unsigned int> mnMSMCookie;
+    o3tl::optional<unsigned int> mnFDOCookie; // FDO ScreenSaver Inhibit
+    o3tl::optional<unsigned int> mnFDOPMCookie; // FDO PowerManagement Inhibit
+    o3tl::optional<unsigned int> mnGSMCookie;
+    o3tl::optional<unsigned int> mnMSMCookie;
 
-    boost::optional<int> mnXScreenSaverTimeout;
+    o3tl::optional<int> mnXScreenSaverTimeout;
 
 #if !defined(__sun) && !defined(AIX)
     BOOL mbDPMSWasEnabled;
diff --git a/vcl/inc/wall2.hxx b/vcl/inc/wall2.hxx
index 37cd4fa66812..ec96d905cc7c 100644
--- a/vcl/inc/wall2.hxx
+++ b/vcl/inc/wall2.hxx
@@ -20,14 +20,14 @@
 #ifndef INCLUDED_VCL_INC_WALL2_HXX
 #define INCLUDED_VCL_INC_WALL2_HXX
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 
 class ImplWallpaper
 {
     friend class Wallpaper;
 
 private:
-    boost::optional<tools::Rectangle>  mpRect;
+    o3tl::optional<tools::Rectangle>  mpRect;
     std::unique_ptr<BitmapEx>   mpBitmap;
     std::unique_ptr<Gradient>   mpGradient;
     std::unique_ptr<BitmapEx>   mpCache;
diff --git a/vcl/inc/window.h b/vcl/inc/window.h
index ab2e1497b301..970e7c58b0c3 100644
--- a/vcl/inc/window.h
+++ b/vcl/inc/window.h
@@ -31,7 +31,7 @@
 #include <o3tl/typed_flags_set.hxx>
 #include <cppuhelper/weakref.hxx>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #include <list>
 #include <memory>
 #include <vector>
@@ -97,20 +97,20 @@ bool ImplWindowFrameProc( vcl::Window* pInst, SalEvent nEvent, const void* pEven
 
 struct ImplWinData
 {
-    boost::optional<OUString>
+    o3tl::optional<OUString>
                         mpExtOldText;
     std::unique_ptr<ExtTextInputAttr[]>
                         mpExtOldAttrAry;
-    boost::optional<tools::Rectangle>
+    o3tl::optional<tools::Rectangle>
                         mpCursorRect;
     long                mnCursorExtWidth;
     bool                mbVertical;
     std::unique_ptr<tools::Rectangle[]>
                         mpCompositionCharRects;
     long                mnCompositionCharRects;
-    boost::optional<tools::Rectangle>
+    o3tl::optional<tools::Rectangle>
                         mpFocusRect;
-    boost::optional<tools::Rectangle>
+    o3tl::optional<tools::Rectangle>
                         mpTrackRect;
     ShowTrackFlags      mnTrackFlags;
     sal_uInt16          mnIsTopWindow;
@@ -183,9 +183,9 @@ struct ImplFrameData
 struct ImplAccessibleInfos
 {
     sal_uInt16          nAccessibleRole;
-    boost::optional<OUString>
+    o3tl::optional<OUString>
                         pAccessibleName;
-    boost::optional<OUString>
+    o3tl::optional<OUString>
                         pAccessibleDescription;
     VclPtr<vcl::Window> pLabeledByWindow;
     VclPtr<vcl::Window> pLabelForWindow;
diff --git a/vcl/qt5/Qt5Frame.cxx b/vcl/qt5/Qt5Frame.cxx
index 21916ee56f13..070e17a742a9 100644
--- a/vcl/qt5/Qt5Frame.cxx
+++ b/vcl/qt5/Qt5Frame.cxx
@@ -651,8 +651,8 @@ void Qt5Frame::StartPresentation(bool bStart)
 // meh - so there's no Qt platform independent solution
 // https://forum.qt.io/topic/38504/solved-qdialog-in-fullscreen-disable-os-screensaver
 #if QT5_USING_X11
-    boost::optional<unsigned int> aRootWindow;
-    boost::optional<Display*> aDisplay;
+    o3tl::optional<unsigned int> aRootWindow;
+    o3tl::optional<Display*> aDisplay;
 
     if (QX11Info::isPlatformX11())
     {
diff --git a/vcl/source/app/settings.cxx b/vcl/source/app/settings.cxx
index 18c6f0f536ee..bf50a8150d47 100644
--- a/vcl/source/app/settings.cxx
+++ b/vcl/source/app/settings.cxx
@@ -199,7 +199,7 @@ struct ImplStyleData
 
     BitmapEx                        maPersonaHeaderBitmap; ///< Cache the header bitmap.
     BitmapEx                        maPersonaFooterBitmap; ///< Cache the footer bitmap.
-    boost::optional<Color>          maPersonaMenuBarTextColor; ///< Cache the menubar color.
+    o3tl::optional<Color>          maPersonaMenuBarTextColor; ///< Cache the menubar color.
 };
 
 struct ImplMiscData
@@ -2098,7 +2098,7 @@ enum WhichPersona { PERSONA_HEADER, PERSONA_FOOTER };
 }
 
 /** Update the setting of the Persona header / footer in ImplStyleData */
-static void setupPersonaHeaderFooter( WhichPersona eWhich, OUString& rHeaderFooter, BitmapEx& rHeaderFooterBitmap, boost::optional<Color>& rMenuBarTextColor )
+static void setupPersonaHeaderFooter( WhichPersona eWhich, OUString& rHeaderFooter, BitmapEx& rHeaderFooterBitmap, o3tl::optional<Color>& rMenuBarTextColor )
 {
     uno::Reference< uno::XComponentContext > xContext( comphelper::getProcessComponentContext() );
     if ( !xContext.is() )
@@ -2191,7 +2191,7 @@ BitmapEx const & StyleSettings::GetPersonaFooter() const
     return mxData->maPersonaFooterBitmap;
 }
 
-const boost::optional<Color>& StyleSettings::GetPersonaMenuBarTextColor() const
+const o3tl::optional<Color>& StyleSettings::GetPersonaMenuBarTextColor() const
 {
     GetPersonaHeader();
     return mxData->maPersonaMenuBarTextColor;
diff --git a/vcl/source/control/quickselectionengine.cxx b/vcl/source/control/quickselectionengine.cxx
index aff324a4eb65..5b76b0352872 100644
--- a/vcl/source/control/quickselectionengine.cxx
+++ b/vcl/source/control/quickselectionengine.cxx
@@ -25,7 +25,7 @@
 #include <vcl/settings.hxx>
 #include <sal/log.hxx>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 
 namespace vcl
 {
@@ -34,7 +34,7 @@ namespace vcl
     {
         ISearchableStringList&              rEntryList;
         OUString                            sCurrentSearchString;
-        ::boost::optional< sal_Unicode >    aSingleSearchChar;
+        ::o3tl::optional< sal_Unicode >    aSingleSearchChar;
         Timer                               aSearchTimeout;
 
         explicit QuickSelectionEngine_Data( ISearchableStringList& _entryList )
diff --git a/vcl/source/fontsubset/sft.cxx b/vcl/source/fontsubset/sft.cxx
index c0c0c709e8a2..8c428653c1e9 100644
--- a/vcl/source/fontsubset/sft.cxx
+++ b/vcl/source/fontsubset/sft.cxx
@@ -2601,8 +2601,8 @@ append(std::bitset<N> & rSet, size_t const nOffset, sal_uInt32 const nValue)
 }
 
 bool getTTCoverage(
-    boost::optional<std::bitset<UnicodeCoverage::MAX_UC_ENUM>> &rUnicodeRange,
-    boost::optional<std::bitset<CodePageCoverage::MAX_CP_ENUM>> &rCodePageRange,
+    o3tl::optional<std::bitset<UnicodeCoverage::MAX_UC_ENUM>> &rUnicodeRange,
+    o3tl::optional<std::bitset<CodePageCoverage::MAX_CP_ENUM>> &rCodePageRange,
     const unsigned char* pTable, size_t nLength)
 {
     bool bRet = false;
diff --git a/vcl/unx/generic/window/salframe.cxx b/vcl/unx/generic/window/salframe.cxx
index 2ffb60b4999b..65da95ac09bf 100644
--- a/vcl/unx/generic/window/salframe.cxx
+++ b/vcl/unx/generic/window/salframe.cxx
@@ -57,7 +57,7 @@
 #include <svdata.hxx>
 #include <bitmaps.hlst>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 
 #include <algorithm>
 
diff --git a/vcl/unx/generic/window/screensaverinhibitor.cxx b/vcl/unx/generic/window/screensaverinhibitor.cxx
index 87dd4ab3df7f..8c84a3ae5345 100644
--- a/vcl/unx/generic/window/screensaverinhibitor.cxx
+++ b/vcl/unx/generic/window/screensaverinhibitor.cxx
@@ -47,7 +47,7 @@
 #include <sal/log.hxx>
 
 void ScreenSaverInhibitor::inhibit( bool bInhibit, const OUString& sReason,
-                                    bool bIsX11, const boost::optional<unsigned int>& xid, boost::optional<Display*> pDisplay )
+                                    bool bIsX11, const o3tl::optional<unsigned int>& xid, o3tl::optional<Display*> pDisplay )
 {
     const char* appname = SalGenericSystem::getFrameClassName();
     const OString aReason = OUStringToOString( sReason, RTL_TEXTENCODING_UTF8 );
@@ -77,7 +77,7 @@ static void dbusInhibit( bool bInhibit,
                   const gchar* service, const gchar* path, const gchar* interface,
                   const std::function<GVariant*( GDBusProxy*, GError*& )>& fInhibit,
                   const std::function<GVariant*( GDBusProxy*, const guint, GError*& )>& fUnInhibit,
-                  boost::optional<guint>& rCookie )
+                  o3tl::optional<guint>& rCookie )
 {
     if ( ( !bInhibit && !rCookie ) ||
          (  bInhibit &&  rCookie ) )
diff --git a/vcl/unx/gtk3/gtk3gtkframe.cxx b/vcl/unx/gtk3/gtk3gtkframe.cxx
index 0d1348b8e551..91df150c26cf 100644
--- a/vcl/unx/gtk3/gtk3gtkframe.cxx
+++ b/vcl/unx/gtk3/gtk3gtkframe.cxx
@@ -1888,8 +1888,8 @@ void GtkSalFrame::ShowFullScreen( bool bFullScreen, sal_Int32 nScreen )
 
 void GtkSalFrame::StartPresentation( bool bStart )
 {
-    boost::optional<guint> aWindow;
-    boost::optional<Display*> aDisplay;
+    o3tl::optional<guint> aWindow;
+    o3tl::optional<Display*> aDisplay;
     if( getDisplay()->IsX11Display() )
     {
         aWindow = widget_get_xid(m_pWindow);
diff --git a/vcl/unx/gtk3/gtk3salnativewidgets-gtk.cxx b/vcl/unx/gtk3/gtk3salnativewidgets-gtk.cxx
index 8a2e998f4e74..3e2b92568c5b 100644
--- a/vcl/unx/gtk3/gtk3salnativewidgets-gtk.cxx
+++ b/vcl/unx/gtk3/gtk3salnativewidgets-gtk.cxx
@@ -23,7 +23,7 @@
 #include <unx/fontmanager.hxx>
 
 #include "cairo_gtk3_cairo.hxx"
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 
 GtkStyleContext* GtkSalGraphics::mpWindowStyle = nullptr;
 GtkStyleContext* GtkSalGraphics::mpButtonStyle = nullptr;
diff --git a/vcl/unx/kf5/KF5SalFrame.cxx b/vcl/unx/kf5/KF5SalFrame.cxx
index a212759aeb91..ba34839a1291 100644
--- a/vcl/unx/kf5/KF5SalFrame.cxx
+++ b/vcl/unx/kf5/KF5SalFrame.cxx
@@ -40,7 +40,7 @@
 
 #include <svdata.hxx>
 
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 
 KF5SalFrame::KF5SalFrame(KF5SalFrame* pParent, SalFrameStyleFlags nState, bool bUseCairo)
     : Qt5Frame(pParent, nState, bUseCairo)
diff --git a/vcl/win/gdi/salnativewidgets-luna.cxx b/vcl/win/gdi/salnativewidgets-luna.cxx
index 41189555e55a..d0d0a07b8105 100644
--- a/vcl/win/gdi/salnativewidgets-luna.cxx
+++ b/vcl/win/gdi/salnativewidgets-luna.cxx
@@ -51,7 +51,7 @@
 
 #include <map>
 #include <string>
-#include <boost/optional.hpp>
+#include <o3tl/optional.hxx>
 #include <ControlCacheKey.hxx>
 
 using namespace std;
diff --git a/vcl/win/window/salframe.cxx b/vcl/win/window/salframe.cxx
index 944acf6cd52d..b9e3b7026a81 100644
--- a/vcl/win/window/salframe.cxx
+++ b/vcl/win/window/salframe.cxx
@@ -2648,7 +2648,7 @@ void WinSalFrame::UpdateSettings( AllSettings& rSettings )
     aStyleSettings.SetUseFlatBorders( false );
     aStyleSettings.SetUseFlatMenus( false );
     aStyleSettings.SetMenuTextColor( ImplWinColorToSal( GetSysColor( COLOR_MENUTEXT ) ) );
-    if ( boost::optional<Color> aColor = aStyleSettings.GetPersonaMenuBarTextColor() )
+    if ( o3tl::optional<Color> aColor = aStyleSettings.GetPersonaMenuBarTextColor() )
     {
         aStyleSettings.SetMenuBarTextColor( *aColor );
         aStyleSettings.SetMenuBarRolloverTextColor( *aColor );