Revert "Remove support for MSVC"

sky/engine/wtf/TypeTraits.h

  /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2009, 2010 Google Inc. All rights reserved.
  *
  * 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
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 43 matching lines @@
     template<> struct IsInteger<signed char>        { static const bool value = true; };
     template<> struct IsInteger<unsigned char>      { static const bool value = true; };
     template<> struct IsInteger<short>              { static const bool value = true; };
     template<> struct IsInteger<unsigned short>     { static const bool value = true; };
     template<> struct IsInteger<int>                { static const bool value = true; };
     template<> struct IsInteger<unsigned int>       { static const bool value = true; };
     template<> struct IsInteger<long>               { static const bool value = true; };
     template<> struct IsInteger<unsigned long>      { static const bool value = true; };
     template<> struct IsInteger<long long>          { static const bool value = true; };
     template<> struct IsInteger<unsigned long long> { static const bool value = true; };
+#if !COMPILER(MSVC) || defined(_NATIVE_WCHAR_T_DEFINED)
     template<> struct IsInteger<wchar_t>            { static const bool value = true; };
+#endif
 
     template<typename T> struct IsFloatingPoint     { static const bool value = false; };
     template<> struct IsFloatingPoint<float>        { static const bool value = true; };
     template<> struct IsFloatingPoint<double>       { static const bool value = true; };
     template<> struct IsFloatingPoint<long double>  { static const bool value = true; };
 
     template<typename T> struct IsArithmetic        { static const bool value = IsInteger<T>::value || IsFloatingPoint<T>::value; };
 
     template<typename T> struct IsWeak              { static const bool value = false; };
 
@@ skipping 230 matching lines @@
             Value = true
         };
     };
 
 template<typename T>
 class NeedsTracing {
     typedef char YesType;
     typedef struct NoType {
         char padding[8];
     } NoType;
+#if COMPILER(MSVC)
+    template<typename V> static YesType checkHasTraceMethod(char[&V::trace != 0]);
+#else
     template<size_t> struct HasMethod;
     template<typename V> static YesType checkHasTraceMethod(HasMethod<sizeof(&V::trace)>*);
+#endif // COMPILER(MSVC)
     template<typename V> static NoType checkHasTraceMethod(...);
 public:
     // We add sizeof(T) to both sides here, because we want it to fail for
     // incomplete types. Otherwise it just assumes that incomplete types do not
     // have a trace method, which may not be true.
     static const bool value = sizeof(YesType) + sizeof(T) == sizeof(checkHasTraceMethod<T>(0)) + sizeof(T);
 };
 
 // Convenience template wrapping the NeedsTracingLazily template in
 // Collection Traits. It helps make the code more readable.
 template<typename Traits>
 class ShouldBeTraced {
 public:
     static const bool value = Traits::template NeedsTracingLazily<>::value;
 };
 
 template<typename T, typename U>
 struct NeedsTracing<std::pair<T, U> > {
     static const bool value = NeedsTracing<T>::value || NeedsTracing<U>::value || IsWeak<T>::value || IsWeak<U>::value;
 };
 
 } // namespace WTF
 
 #endif // TypeTraits_h