QWindowsFontDatabase: port local QSets to QDuplicateTracker

Apart from a more fitting, minimal, API, QDuplicateTracker also
transparently uses C++17 pmr::monotonic_buffer_resource to avoid, or
at least reduce, memory allocations.

Change-Id: I155f5518190c5f8f6d21fbec3fcecd6bcc7ff852
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

1 files changed, 3 insertions, 4 deletions

diff --git a/src/gui/text/windows/qwindowsfontdatabase.cpp b/src/gui/text/windows/qwindowsfontdatabase.cpp
index 58ff99e3a8..c89039ac58 100644
--- a/src/gui/text/windows/qwindowsfontdatabase.cpp
+++ b/src/gui/text/windows/qwindowsfontdatabase.cpp
@@ -51,6 +51,7 @@
 #include <QtCore/QDebug>
 #include <QtCore/QFile>
 #include <QtCore/QtEndian>
+#include <QtCore/private/qduplicatetracker_p.h>
 #include <QtCore/private/qsystemlibrary_p.h>
 #include <QtCore/private/qwinregistry_p.h>
 
@@ -499,7 +500,7 @@ namespace {
         {}
 
         QString populatedFontFamily;
-        QSet<FontAndStyle> foundFontAndStyles;
+        QDuplicateTracker<FontAndStyle> foundFontAndStyles;
         QWindowsFontDatabase *windowsFontDatabase;
     };
 }
@@ -642,10 +643,8 @@ static int QT_WIN_CALLBACK storeFont(const LOGFONT *logFont, const TEXTMETRIC *t
         signature = &reinterpret_cast<const NEWTEXTMETRICEX *>(textmetric)->ntmFontSig;
         // We get a callback for each script-type supported, but we register them all
         // at once using the signature, so we only need one call to addFontToDatabase().
-        FontAndStyle fontAndStyle = {familyName, styleName};
-        if (sfp->foundFontAndStyles.contains(fontAndStyle))
+        if (sfp->foundFontAndStyles.hasSeen({familyName, styleName}))
             return 1;
-        sfp->foundFontAndStyles.insert(fontAndStyle);
     }
     addFontToDatabase(familyName, styleName, *logFont, textmetric, signature, type, sfp);