Replace Qt CONSTEXPR defines with constexpr

Both normal and relaxed constexpr are required by our new minimum of
C++17.

Change-Id: Ic028b88a2e7a6cb7d5925f3133b9d54859a81744
Reviewed-by: Sona Kurazyan <sona.kurazyan@qt.io>

4 files changed, 46 insertions, 80 deletions

diff --git a/src/widgets/itemviews/qlistview_p.h b/src/widgets/itemviews/qlistview_p.h
index 07f4ae4a90..cb41c87043 100644
--- a/src/widgets/itemviews/qlistview_p.h
+++ b/src/widgets/itemviews/qlistview_p.h
@@ -68,28 +68,28 @@ class QListViewItem
     friend class QListModeViewBase;
     friend class QIconModeViewBase;
 public:
-    Q_DECL_CONSTEXPR QListViewItem()
+    constexpr QListViewItem()
         : x(-1), y(-1), w(0), h(0), indexHint(-1), visited(0xffff) {}
-    Q_DECL_CONSTEXPR QListViewItem(QRect r, int i)
+    constexpr QListViewItem(QRect r, int i)
         : x(r.x()), y(r.y()), w(qMin(r.width(), SHRT_MAX)), h(qMin(r.height(), SHRT_MAX)),
           indexHint(i), visited(0xffff) {}
-    Q_DECL_CONSTEXPR bool operator==(const QListViewItem &other) const {
+    constexpr bool operator==(const QListViewItem &other) const {
         return (x == other.x && y == other.y && w == other.w && h == other.h &&
                 indexHint == other.indexHint); }
-    Q_DECL_CONSTEXPR bool operator!=(const QListViewItem &other) const
+    constexpr bool operator!=(const QListViewItem &other) const
         { return !(*this == other); }
-    Q_DECL_CONSTEXPR bool isValid() const
+    constexpr bool isValid() const
         { return rect().isValid() && (indexHint > -1); }
-    Q_DECL_RELAXED_CONSTEXPR void invalidate()
+    constexpr void invalidate()
         { x = -1; y = -1; w = 0; h = 0; }
-    Q_DECL_RELAXED_CONSTEXPR void resize(QSize size)
+    constexpr void resize(QSize size)
         { w = qMin(size.width(), SHRT_MAX); h = qMin(size.height(), SHRT_MAX); }
-    Q_DECL_RELAXED_CONSTEXPR void move(QPoint position)
+    constexpr void move(QPoint position)
         { x = position.x(); y = position.y(); }
-    Q_DECL_CONSTEXPR int width() const { return w; }
-    Q_DECL_CONSTEXPR int height() const { return h; }
+    constexpr int width() const { return w; }
+    constexpr int height() const { return h; }
 private:
-    Q_DECL_CONSTEXPR QRect rect() const
+    constexpr QRect rect() const
         { return QRect(x, y, w, h); }
     int x, y;
     short w, h;
diff --git a/src/widgets/kernel/qsizepolicy.h b/src/widgets/kernel/qsizepolicy.h
index 245a3d069c..5056b91ea7 100644
--- a/src/widgets/kernel/qsizepolicy.h
+++ b/src/widgets/kernel/qsizepolicy.h
@@ -46,22 +46,6 @@
 
 QT_BEGIN_NAMESPACE
 
-// gcc < 4.8.0 has problems with init'ing variant members in constexpr ctors
-// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54922
-#if !defined(Q_CC_GNU) || defined(Q_CC_INTEL) || defined(Q_CC_CLANG) || Q_CC_GNU >= 408
-# define QT_SIZEPOLICY_CONSTEXPR Q_DECL_CONSTEXPR
-# if defined(Q_COMPILER_UNIFORM_INIT)
-#  define QT_SIZEPOLICY_CONSTEXPR_AND_UNIFORM_INIT Q_DECL_CONSTEXPR
-# endif // uniform-init
-#endif
-
-#ifndef QT_SIZEPOLICY_CONSTEXPR
-# define QT_SIZEPOLICY_CONSTEXPR
-#endif
-#ifndef QT_SIZEPOLICY_CONSTEXPR_AND_UNIFORM_INIT
-# define QT_SIZEPOLICY_CONSTEXPR_AND_UNIFORM_INIT
-#endif
-
 class QVariant;
 class QSizePolicy;
 
@@ -110,60 +94,47 @@ public:
     Q_DECLARE_FLAGS(ControlTypes, ControlType)
     Q_FLAG(ControlTypes)
 
-    QT_SIZEPOLICY_CONSTEXPR QSizePolicy() noexcept : data(0) { }
+    constexpr QSizePolicy() noexcept : data(0) { }
 
-#if defined(Q_COMPILER_UNIFORM_INIT) && !defined(Q_QDOC)
-    QT_SIZEPOLICY_CONSTEXPR QSizePolicy(Policy horizontal, Policy vertical, ControlType type = DefaultType) noexcept
+    constexpr QSizePolicy(Policy horizontal, Policy vertical, ControlType type = DefaultType) noexcept
         : bits{0, 0, quint32(horizontal), quint32(vertical),
                type == DefaultType ? 0 : toControlTypeFieldValue(type), 0, 0, 0}
     {}
-#else
-    QSizePolicy(Policy horizontal, Policy vertical, ControlType type = DefaultType) noexcept
-        : data(0) {
-        bits.horPolicy = horizontal;
-        bits.verPolicy = vertical;
-        setControlType(type);
-    }
-#endif // uniform-init
-    QT_SIZEPOLICY_CONSTEXPR Policy horizontalPolicy() const noexcept { return static_cast<Policy>(bits.horPolicy); }
-    QT_SIZEPOLICY_CONSTEXPR Policy verticalPolicy() const noexcept { return static_cast<Policy>(bits.verPolicy); }
+    constexpr Policy horizontalPolicy() const noexcept { return static_cast<Policy>(bits.horPolicy); }
+    constexpr Policy verticalPolicy() const noexcept { return static_cast<Policy>(bits.verPolicy); }
     ControlType controlType() const noexcept;
 
-    Q_DECL_RELAXED_CONSTEXPR void setHorizontalPolicy(Policy d) noexcept { bits.horPolicy = d; }
-    Q_DECL_RELAXED_CONSTEXPR void setVerticalPolicy(Policy d) noexcept { bits.verPolicy = d; }
+    constexpr void setHorizontalPolicy(Policy d) noexcept { bits.horPolicy = d; }
+    constexpr void setVerticalPolicy(Policy d) noexcept { bits.verPolicy = d; }
     void setControlType(ControlType type) noexcept;
 
-    QT_SIZEPOLICY_CONSTEXPR Qt::Orientations expandingDirections() const noexcept {
+    constexpr Qt::Orientations expandingDirections() const noexcept {
         return ( (verticalPolicy()   & ExpandFlag) ? Qt::Vertical   : Qt::Orientations() )
              | ( (horizontalPolicy() & ExpandFlag) ? Qt::Horizontal : Qt::Orientations() ) ;
     }
 
-    Q_DECL_RELAXED_CONSTEXPR void setHeightForWidth(bool b) noexcept { bits.hfw = b;  }
-    QT_SIZEPOLICY_CONSTEXPR bool hasHeightForWidth() const noexcept { return bits.hfw; }
-    Q_DECL_RELAXED_CONSTEXPR void setWidthForHeight(bool b) noexcept { bits.wfh = b;  }
-    QT_SIZEPOLICY_CONSTEXPR bool hasWidthForHeight() const noexcept { return bits.wfh; }
+    constexpr void setHeightForWidth(bool b) noexcept { bits.hfw = b;  }
+    constexpr bool hasHeightForWidth() const noexcept { return bits.hfw; }
+    constexpr void setWidthForHeight(bool b) noexcept { bits.wfh = b;  }
+    constexpr bool hasWidthForHeight() const noexcept { return bits.wfh; }
 
-    QT_SIZEPOLICY_CONSTEXPR bool operator==(const QSizePolicy& s) const noexcept { return data == s.data; }
-    QT_SIZEPOLICY_CONSTEXPR bool operator!=(const QSizePolicy& s) const noexcept { return data != s.data; }
+    constexpr bool operator==(const QSizePolicy& s) const noexcept { return data == s.data; }
+    constexpr bool operator!=(const QSizePolicy& s) const noexcept { return data != s.data; }
 
     friend Q_DECL_CONST_FUNCTION size_t qHash(QSizePolicy key, size_t seed) noexcept { return qHash(key.data, seed); }
 
     operator QVariant() const;
 
-    QT_SIZEPOLICY_CONSTEXPR int horizontalStretch() const noexcept { return static_cast<int>(bits.horStretch); }
-    QT_SIZEPOLICY_CONSTEXPR int verticalStretch() const noexcept { return static_cast<int>(bits.verStretch); }
-    Q_DECL_RELAXED_CONSTEXPR void setHorizontalStretch(int stretchFactor) { bits.horStretch = static_cast<quint32>(qBound(0, stretchFactor, 255)); }
-    Q_DECL_RELAXED_CONSTEXPR void setVerticalStretch(int stretchFactor) { bits.verStretch = static_cast<quint32>(qBound(0, stretchFactor, 255)); }
+    constexpr int horizontalStretch() const noexcept { return static_cast<int>(bits.horStretch); }
+    constexpr int verticalStretch() const noexcept { return static_cast<int>(bits.verStretch); }
+    constexpr void setHorizontalStretch(int stretchFactor) { bits.horStretch = static_cast<quint32>(qBound(0, stretchFactor, 255)); }
+    constexpr void setVerticalStretch(int stretchFactor) { bits.verStretch = static_cast<quint32>(qBound(0, stretchFactor, 255)); }
 
-    QT_SIZEPOLICY_CONSTEXPR bool retainSizeWhenHidden() const noexcept { return bits.retainSizeWhenHidden; }
-    Q_DECL_RELAXED_CONSTEXPR void setRetainSizeWhenHidden(bool retainSize) noexcept { bits.retainSizeWhenHidden = retainSize; }
+    constexpr bool retainSizeWhenHidden() const noexcept { return bits.retainSizeWhenHidden; }
+    constexpr void setRetainSizeWhenHidden(bool retainSize) noexcept { bits.retainSizeWhenHidden = retainSize; }
 
-    Q_DECL_RELAXED_CONSTEXPR void transpose() noexcept { *this = transposed(); }
-    Q_REQUIRED_RESULT
-#ifndef Q_QDOC
-    QT_SIZEPOLICY_CONSTEXPR_AND_UNIFORM_INIT
-#endif
-    QSizePolicy transposed() const noexcept
+    constexpr void transpose() noexcept { *this = transposed(); }
+    Q_REQUIRED_RESULT constexpr QSizePolicy transposed() const noexcept
     {
         return QSizePolicy(bits.transposed());
     }
@@ -173,11 +144,11 @@ private:
     friend Q_WIDGETS_EXPORT QDataStream &operator<<(QDataStream &, const QSizePolicy &);
     friend Q_WIDGETS_EXPORT QDataStream &operator>>(QDataStream &, QSizePolicy &);
 #endif
-    QT_SIZEPOLICY_CONSTEXPR QSizePolicy(int i) noexcept : data(i) { }
+    constexpr QSizePolicy(int i) noexcept : data(i) { }
     struct Bits;
-    QT_SIZEPOLICY_CONSTEXPR explicit QSizePolicy(Bits b) noexcept : bits(b) { }
+    constexpr explicit QSizePolicy(Bits b) noexcept : bits(b) { }
 
-    static Q_DECL_RELAXED_CONSTEXPR quint32 toControlTypeFieldValue(ControlType type) noexcept
+    static constexpr quint32 toControlTypeFieldValue(ControlType type) noexcept
     {
         /*
           The control type is a flag type, with values 0x1, 0x2, 0x4, 0x8, 0x10,
@@ -206,8 +177,7 @@ private:
         quint32 wfh : 1;
         quint32 retainSizeWhenHidden : 1;
 
-        QT_SIZEPOLICY_CONSTEXPR_AND_UNIFORM_INIT
-        Bits transposed() const noexcept
+        constexpr Bits transposed() const noexcept
         {
             return {verStretch, // \ swap
                     horStretch, // /
@@ -238,10 +208,6 @@ Q_WIDGETS_EXPORT QDataStream &operator>>(QDataStream &, QSizePolicy &);
 Q_WIDGETS_EXPORT QDebug operator<<(QDebug dbg, const QSizePolicy &);
 #endif
 
-
-#undef QT_SIZEPOLICY_CONSTEXPR
-#undef QT_SIZEPOLICY_CONSTEXPR_AND_UNIFORM_INIT
-
 QT_END_NAMESPACE
 
 #endif // QSIZEPOLICY_H
diff --git a/src/widgets/styles/qcommonstyle.cpp b/src/widgets/styles/qcommonstyle.cpp
index 1f1fc73727..bb646accf6 100644
--- a/src/widgets/styles/qcommonstyle.cpp
+++ b/src/widgets/styles/qcommonstyle.cpp
@@ -3194,9 +3194,9 @@ struct StaticPolygonF
 {
     QPointF data[N];
 
-    Q_DECL_CONSTEXPR int size() const { return N; }
-    Q_DECL_CONSTEXPR const QPointF *cbegin() const { return data; }
-    Q_DECL_CONSTEXPR const QPointF &operator[](int idx) const { return data[idx]; }
+    constexpr int size() const { return N; }
+    constexpr const QPointF *cbegin() const { return data; }
+    constexpr const QPointF &operator[](int idx) const { return data[idx]; }
 };
 
 static StaticPolygonF<3> calcArrow(const QStyleOptionSlider *dial, qreal &a)
diff --git a/src/widgets/widgets/qcalendarwidget.cpp b/src/widgets/widgets/qcalendarwidget.cpp
index be3d275375..68cd7e8451 100644
--- a/src/widgets/widgets/qcalendarwidget.cpp
+++ b/src/widgets/widgets/qcalendarwidget.cpp
@@ -426,7 +426,7 @@ QString QCalendarYearValidator::text(QDate date, QCalendar cal, int repeat) cons
 ///////////////////////////////////
 
 struct SectionToken {
-    Q_DECL_CONSTEXPR SectionToken(QCalendarDateSectionValidator *v, int rep)
+    constexpr SectionToken(QCalendarDateSectionValidator *v, int rep)
         : validator(v), repeat(rep) {}
 
     QCalendarDateSectionValidator *validator;
@@ -826,9 +826,9 @@ class StaticDayOfWeekAssociativeArray {
     bool contained[7];
     T data[7];
 
-    static Q_DECL_CONSTEXPR int day2idx(Qt::DayOfWeek day) noexcept { return int(day) - 1; } // alt: day % 7
+    static constexpr int day2idx(Qt::DayOfWeek day) noexcept { return int(day) - 1; } // alt: day % 7
 public:
-    Q_DECL_CONSTEXPR StaticDayOfWeekAssociativeArray() noexcept(noexcept(T()))
+    constexpr StaticDayOfWeekAssociativeArray() noexcept(noexcept(T()))
 #ifdef Q_COMPILER_CONSTEXPR
         : contained{}, data{}   // arrays require uniform initialization
 #else
@@ -836,17 +836,17 @@ public:
 #endif
     {}
 
-    Q_DECL_CONSTEXPR bool contains(Qt::DayOfWeek day) const noexcept { return contained[day2idx(day)]; }
-    Q_DECL_CONSTEXPR const T &value(Qt::DayOfWeek day) const noexcept { return data[day2idx(day)]; }
+    constexpr bool contains(Qt::DayOfWeek day) const noexcept { return contained[day2idx(day)]; }
+    constexpr const T &value(Qt::DayOfWeek day) const noexcept { return data[day2idx(day)]; }
 
-    Q_DECL_RELAXED_CONSTEXPR T &operator[](Qt::DayOfWeek day) noexcept
+    constexpr T &operator[](Qt::DayOfWeek day) noexcept
     {
         const int idx = day2idx(day);
         contained[idx] = true;
         return data[idx];
     }
 
-    Q_DECL_RELAXED_CONSTEXPR void insert(Qt::DayOfWeek day, T v) noexcept
+    constexpr void insert(Qt::DayOfWeek day, T v) noexcept
     {
         operator[](day).swap(v);
     }