Move enum conversions over into QMetaType

Take the opportunity to properly handle the underlying type
(size and signed vs unsigned).

Change-Id: I0cb8cf40acac6de03c24ed3fe570db68268952c8
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/src/corelib/kernel/qmetatype.h b/src/corelib/kernel/qmetatype.h
index a6c415b268..b4217bc3a1 100644
--- a/src/corelib/kernel/qmetatype.h
+++ b/src/corelib/kernel/qmetatype.h
@@ -356,6 +356,7 @@ public:
         IsGadget = 0x200,
         PointerToGadget = 0x400,
         IsPointer = 0x800,
+        IsUnsignedEnumeration = 0x1000
     };
     Q_DECLARE_FLAGS(TypeFlags, TypeFlag)
 
@@ -1428,6 +1429,11 @@ namespace QtPrivate {
     template <typename Result, typename... Args>
     struct IsPointerToTypeDerivedFromQObject<Result(*)(Args...)> { enum { Value = false }; };
 
+    template<typename T, bool = std::is_enum<T>::value>
+    constexpr bool IsUnsignedEnum = false;
+    template<typename T>
+    constexpr bool IsUnsignedEnum<T, true> = !std::is_signed_v<std::underlying_type_t<T>>;
+
     template<typename T>
     struct QMetaTypeTypeFlags
     {
@@ -1442,6 +1448,7 @@ namespace QtPrivate {
                      | (IsGadgetHelper<T>::IsGadgetOrDerivedFrom ? QMetaType::IsGadget : 0)
                      | (IsPointerToGadgetHelper<T>::IsGadgetOrDerivedFrom ? QMetaType::PointerToGadget : 0)
                      | (QTypeInfo<T>::isPointer ? QMetaType::IsPointer : 0)
+                     | (IsUnsignedEnum<T> ? QMetaType::IsUnsignedEnumeration : 0)
              };
     };