Add TypeTraits template for checking safe bitfields (WIP)

third_party/WebKit/Source/core/style/ComputedStyle.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 54 matching lines @@
 #include "platform/geometry/FloatRoundedRect.h"
 #include "platform/geometry/LayoutRectOutsets.h"
 #include "platform/graphics/Color.h"
 #include "platform/scroll/ScrollTypes.h"
 #include "platform/text/TextDirection.h"
 #include "platform/text/UnicodeBidi.h"
 #include "platform/transforms/TransformOperations.h"
 #include "wtf/Forward.h"
 #include "wtf/LeakAnnotations.h"
 #include "wtf/RefCounted.h"
+#include "wtf/TypeTraits.h"
 #include "wtf/Vector.h"
 #include <memory>
 
 template<typename T, typename U> inline bool compareEqual(const T& t, const U& u) { return t == static_cast<T>(u); }
 
 #define SET_VAR(group, variable, value) \
     if (!compareEqual(group->variable, value)) \
         group.access()->variable = value
 
 #define SET_NESTED_VAR(group, base, variable, value)            \
@@ skipping 94 matching lines @@
                 && (m_boxDirection == other.m_boxDirection)
                 && (m_rtlOrdering == other.m_rtlOrdering)
                 && (m_printColorAdjust == other.m_printColorAdjust)
                 && (m_pointerEvents == other.m_pointerEvents)
                 && (m_insideLink == other.m_insideLink)
                 && (m_writingMode == other.m_writingMode);
         }
 
         bool operator!=(const InheritedData& other) const { return !(*this == other); }
 
+        static_assert(IsEnumSafeToStoreInBitfield<EVisibility>::value, "EVisibility is stored in a bitfield on ComputedStyle");
+
         unsigned m_emptyCells : 1; // EEmptyCells
         unsigned m_captionSide : 2; // ECaptionSide
         unsigned m_listStyleType : 7; // EListStyleType
         unsigned m_listStylePosition : 1; // EListStylePosition
-        unsigned m_visibility : 2; // EVisibility
+        EVisibility m_visibility : 2;
         unsigned m_textAlign : 4; // ETextAlign
         unsigned m_textTransform : 2; // ETextTransform
         unsigned m_textUnderline : 1;
         unsigned m_cursorStyle : 6; // ECursor
         unsigned m_direction : 1; // TextDirection
         unsigned m_whiteSpace : 3; // EWhiteSpace
         unsigned m_borderCollapse : 1; // EBorderCollapse
         unsigned m_boxDirection : 1; // EBoxDirection (CSS3 box_direction property, flexible box layout module)
         // 32 bits
 
@@ skipping 87 matching lines @@
     } m_nonInheritedData;
 
 // !END SYNC!
 
     void setBitDefaults()
     {
         m_inheritedData.m_emptyCells = initialEmptyCells();
         m_inheritedData.m_captionSide = initialCaptionSide();
         m_inheritedData.m_listStyleType = initialListStyleType();
         m_inheritedData.m_listStylePosition = initialListStylePosition();
-        m_inheritedData.m_visibility = static_cast<unsigned>(initialVisibility());
+        m_inheritedData.m_visibility = initialVisibility();
         m_inheritedData.m_textAlign = initialTextAlign();
         m_inheritedData.m_textTransform = initialTextTransform();
         m_inheritedData.m_textUnderline = false;
         m_inheritedData.m_cursorStyle = initialCursor();
         m_inheritedData.m_direction = initialDirection();
         m_inheritedData.m_whiteSpace = initialWhiteSpace();
         m_inheritedData.m_borderCollapse = initialBorderCollapse();
         m_inheritedData.m_rtlOrdering = initialRTLOrdering();
         m_inheritedData.m_boxDirection = initialBoxDirection();
         m_inheritedData.m_printColorAdjust = initialPrintColorAdjust();
@@ skipping 1151 matching lines @@
     void setTextSizeAdjust(TextSizeAdjust sizeAdjust) { SET_VAR(m_rareInheritedData, m_textSizeAdjust, sizeAdjust); }
 
     // text-transform (aka -epub-text-transform)
     static ETextTransform initialTextTransform() { return TTNONE; }
     ETextTransform textTransform() const { return static_cast<ETextTransform>(m_inheritedData.m_textTransform); }
     void setTextTransform(ETextTransform v) { m_inheritedData.m_textTransform = v; }
 
     // visibility
     static EVisibility initialVisibility() { return EVisibility::Visible; }
     EVisibility visibility() const { return static_cast<EVisibility>(m_inheritedData.m_visibility); }
-    void setVisibility(EVisibility v) { m_inheritedData.m_visibility = static_cast<unsigned>(v); }
+    void setVisibility(EVisibility v) { m_inheritedData.m_visibility = v; }
 
     // white-space inherited
     static EWhiteSpace initialWhiteSpace() { return NORMAL; }
     EWhiteSpace whiteSpace() const { return static_cast<EWhiteSpace>(m_inheritedData.m_whiteSpace); }
     void setWhiteSpace(EWhiteSpace v) { m_inheritedData.m_whiteSpace = v; }
 
     // word-break inherited (aka -epub-word-break)
     static EWordBreak initialWordBreak() { return NormalWordBreak; }
     EWordBreak wordBreak() const { return static_cast<EWordBreak>(m_rareInheritedData->wordBreak); }
     void setWordBreak(EWordBreak b) { SET_VAR(m_rareInheritedData, wordBreak, b); }
@@ skipping 1070 matching lines @@
 }
 
 inline bool ComputedStyle::hasPseudoElementStyle() const
 {
     return m_nonInheritedData.m_pseudoBits & ElementPseudoIdMask;
 }
 
 } // namespace blink
 
 #endif // ComputedStyle_h