QWindowsFontDatabase: replace a QPair with a dedicated struct

Pairs are easy to use, but they have no semantics attached: Two
QPair<QString, QString> compare equal, e.g., even though one is used
as a FontAndStyle and the other as, say, a type/subtype. It also
carries no information for the reader of the code.

So, write a minimal struct with equality and qHash() instead.

Change-Id: I9514c9b7d6c2cc6a4831f9ca83ca2ee466d91553
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

1 files changed, 15 insertions, 0 deletions

diff --git a/src/platformsupport/fontdatabases/windows/qwindowsfontdatabase_p.h b/src/platformsupport/fontdatabases/windows/qwindowsfontdatabase_p.h
index 38ddb178bd..0652685fc5 100644
--- a/src/platformsupport/fontdatabases/windows/qwindowsfontdatabase_p.h
+++ b/src/platformsupport/fontdatabases/windows/qwindowsfontdatabase_p.h
@@ -56,6 +56,7 @@
 #include <qpa/qplatformfontdatabase.h>
 #include <QtCore/QSharedPointer>
 #include <QtCore/QLoggingCategory>
+#include <QtCore/qhashfunctions.h>
 #include <QtCore/qt_windows.h>
 
 QT_BEGIN_NAMESPACE
@@ -154,6 +155,20 @@ bool qt_localizedName(const QString &name);
 QString qt_getEnglishName(const QString &familyName, bool includeStyle = false);
 QFontNames qt_getCanonicalFontNames(const LOGFONT &lf);
 
+struct FontAndStyle {
+    QString font;
+    QString style;
+
+    friend inline bool operator==(const FontAndStyle &lhs, const FontAndStyle &rhs) noexcept
+    { return lhs.font == rhs.font && lhs.style == rhs.style; }
+    friend inline bool operator!=(const FontAndStyle &lhs, const FontAndStyle &rhs) noexcept
+    { return !operator==(lhs, rhs); }
+};
+inline size_t qHash(const FontAndStyle &key, size_t seed) noexcept
+{
+    return qHashMulti(seed, key.font, key.style);
+}
+
 QT_END_NAMESPACE
 
 #endif // QWINDOWSFONTDATABASE_H