Make QFlags enum flags (C++11 strict enums) friendly

Change-Id: I9ccb3e4d281a545ca1845db4f6aa7ac6c04e8621
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>

src/corelib/global/qflags.h

@@ -97,31 +97,32 @@ public:
     inline QFlags(const QFlags &other);
     inline QFlags &operator=(const QFlags &other);
 #endif
-    Q_DECL_CONSTEXPR inline QFlags(Enum f) : i(f) {}
+    Q_DECL_CONSTEXPR inline QFlags(Enum f) : i(Int(f)) {}
     Q_DECL_CONSTEXPR inline QFlags(Zero = 0) : i(0) {}
     Q_DECL_CONSTEXPR inline QFlags(QFlag f) : i(f) {}
 
     inline QFlags &operator&=(int mask) { i &= mask; return *this; }
     inline QFlags &operator&=(uint mask) { i &= mask; return *this; }
+    inline QFlags &operator&=(Enum mask) { i &= Int(mask); return *this; }
     inline QFlags &operator|=(QFlags f) { i |= f.i; return *this; }
-    inline QFlags &operator|=(Enum f) { i |= f; return *this; }
+    inline QFlags &operator|=(Enum f) { i |= Int(f); return *this; }
     inline QFlags &operator^=(QFlags f) { i ^= f.i; return *this; }
-    inline QFlags &operator^=(Enum f) { i ^= f; return *this; }
+    inline QFlags &operator^=(Enum f) { i ^= Int(f); return *this; }
 
     Q_DECL_CONSTEXPR  inline operator Int() const { return i; }
 
     Q_DECL_CONSTEXPR inline QFlags operator|(QFlags f) const { return QFlags(Enum(i | f.i)); }
-    Q_DECL_CONSTEXPR inline QFlags operator|(Enum f) const { return QFlags(Enum(i | f)); }
+    Q_DECL_CONSTEXPR inline QFlags operator|(Enum f) const { return QFlags(Enum(i | Int(f))); }
     Q_DECL_CONSTEXPR inline QFlags operator^(QFlags f) const { return QFlags(Enum(i ^ f.i)); }
-    Q_DECL_CONSTEXPR inline QFlags operator^(Enum f) const { return QFlags(Enum(i ^ f)); }
+    Q_DECL_CONSTEXPR inline QFlags operator^(Enum f) const { return QFlags(Enum(i ^ Int(f))); }
     Q_DECL_CONSTEXPR inline QFlags operator&(int mask) const { return QFlags(Enum(i & mask)); }
     Q_DECL_CONSTEXPR inline QFlags operator&(uint mask) const { return QFlags(Enum(i & mask)); }
-    Q_DECL_CONSTEXPR inline QFlags operator&(Enum f) const { return QFlags(Enum(i & f)); }
+    Q_DECL_CONSTEXPR inline QFlags operator&(Enum f) const { return QFlags(Enum(i & Int(f))); }
     Q_DECL_CONSTEXPR inline QFlags operator~() const { return QFlags(Enum(~i)); }
 
     Q_DECL_CONSTEXPR inline bool operator!() const { return !i; }
 
-    Q_DECL_CONSTEXPR inline bool testFlag(Enum f) const { return (i & f) == f && (f != 0 || i == Int(f) ); }
+    Q_DECL_CONSTEXPR inline bool testFlag(Enum f) const { return (i & Int(f)) == Int(f) && (Int(f) != 0 || i == Int(f) ); }
 private:
     Int i;
 };

src/corelib/global/qglobal.cpp

@@ -239,6 +239,12 @@ Q_CORE_EXPORT void *qMemSet(void *dest, int c, size_t n);
     \overload
 */
 
+/*!
+    \fn QFlags &QFlags::operator&=(Enum mask)
+
+    \overload
+*/
+
 /*!
     \fn QFlags &QFlags::operator|=(QFlags other)
 

src/corelib/io/qdebug.h

@@ -280,7 +280,7 @@ inline QDebug operator<<(QDebug debug, const QFlags<T> &flags)
                 debug.nospace() << '|';
             else
                 needSeparator = true;
-            debug.nospace() << "0x" << QByteArray::number(T(1 << i), 16).constData();
+            debug.nospace() << "0x" << QByteArray::number(typename QFlags<T>::Int(1) << i, 16).constData();
         }
     }
     debug << ')';

tests/auto/corelib/global/qflags/tst_qflags.cpp

@@ -49,6 +49,7 @@ private slots:
     void testFlagMultiBits() const;
     void constExpr();
     void signedness();
+    void classEnum();
 };
 
 void tst_QFlags::testFlag() const
@@ -137,6 +138,121 @@ void tst_QFlags::signedness()
                      QtPrivate::is_signed<Qt::Alignment::Int>::value));
 }
 
+#if defined(Q_COMPILER_CLASS_ENUM)
+enum class MyStrictEnum { StrictZero, StrictOne, StrictTwo, StrictFour=4 };
+Q_DECLARE_FLAGS( MyStrictFlags, MyStrictEnum )
+Q_DECLARE_OPERATORS_FOR_FLAGS( MyStrictFlags )
+
+Q_STATIC_ASSERT( !QTypeInfo<MyStrictFlags>::isComplex );
+Q_STATIC_ASSERT( !QTypeInfo<MyStrictFlags>::isStatic );
+Q_STATIC_ASSERT( !QTypeInfo<MyStrictFlags>::isLarge );
+Q_STATIC_ASSERT( !QTypeInfo<MyStrictFlags>::isPointer );
+#endif
+
+void tst_QFlags::classEnum()
+{
+#if defined(Q_COMPILER_CLASS_ENUM)
+    // The main aim of the test is making sure it compiles
+    // The QCOMPARE are there as an extra
+    MyStrictEnum e1 = MyStrictEnum::StrictOne;
+    MyStrictEnum e2 = MyStrictEnum::StrictTwo;
+
+    MyStrictFlags f1(MyStrictEnum::StrictOne);
+    QCOMPARE(f1, 1);
+
+    MyStrictFlags f2(e2);
+    QCOMPARE(f2, 2);
+
+    MyStrictFlags f0;
+    QCOMPARE(f0, 0);
+
+    MyStrictFlags f3(e2 | e1);
+    QCOMPARE(f3, 3);
+
+    QVERIFY(f3.testFlag(MyStrictEnum::StrictOne));
+    QVERIFY(!f1.testFlag(MyStrictEnum::StrictTwo));
+
+    QVERIFY(!f0);
+
+    QCOMPARE(f3 & int(1), 1);
+    QCOMPARE(f3 & uint(1), 1);
+    QCOMPARE(f3 & MyStrictEnum::StrictOne, 1);
+
+    MyStrictFlags aux;
+    aux = f3;
+    aux &= int(1);
+    QCOMPARE(aux, 1);
+
+    aux = f3;
+    aux &= uint(1);
+    QCOMPARE(aux, 1);
+
+    aux = f3;
+    aux &= MyStrictEnum::StrictOne;
+    QCOMPARE(aux, 1);
+
+    aux = f3;
+    aux &= f1;
+    QCOMPARE(aux, 1);
+
+    aux = f3 ^ f3;
+    QCOMPARE(aux, 0);
+
+    aux = f3 ^ f1;
+    QCOMPARE(aux, 2);
+
+    aux = f3 ^ f0;
+    QCOMPARE(aux, 3);
+
+    aux = f3 ^ MyStrictEnum::StrictOne;
+    QCOMPARE(aux, 2);
+
+    aux = f3 ^ MyStrictEnum::StrictZero;
+    QCOMPARE(aux, 3);
+
+    aux = f3;
+    aux ^= f3;
+    QCOMPARE(aux, 0);
+
+    aux = f3;
+    aux ^= f1;
+    QCOMPARE(aux, 2);
+
+    aux = f3;
+    aux ^= f0;
+    QCOMPARE(aux, 3);
+
+    aux = f3;
+    aux ^= MyStrictEnum::StrictOne;
+    QCOMPARE(aux, 2);
+
+    aux = f3;
+    aux ^= MyStrictEnum::StrictZero;
+    QCOMPARE(aux, 3);
+
+    aux = f1 | f2;
+    QCOMPARE(aux, 3);
+
+    aux = MyStrictEnum::StrictOne | MyStrictEnum::StrictTwo;
+    QCOMPARE(aux, 3);
+
+    aux = f1;
+    aux |= f2;
+    QCOMPARE(aux, 3);
+
+    aux = MyStrictEnum::StrictOne;
+    aux |= MyStrictEnum::StrictTwo;
+    QCOMPARE(aux, 3);
+
+    aux = ~f1;
+    QCOMPARE(aux, -2);
+
+    // Just to make sure it compiles
+    if (false)
+        qDebug() << f3;
+#endif
+}
+
 // (statically) check QTypeInfo for QFlags instantiations:
 enum MyEnum { Zero, One, Two, Four=4 };
 Q_DECLARE_FLAGS( MyFlags, MyEnum )