Check noexcept in VariantImpl

Author: sfodagain

include/aws/crt/Variant.h

@@ -178,11 +178,16 @@ namespace Aws
                     VariantDetail::Checker::HasType<typename std::decay<OtherT>::type, Ts...>::value,
                     int>::type;
 
+                using FirstAlternative = typename ThisVariantAlternative<0>::type;
+
+                static constexpr bool isFirstAlternativeNothrowDefaultConstructible =
+                    std::is_nothrow_default_constructible<FirstAlternative>::value;
+
               public:
                 using IndexT = VariantDetail::Index::VariantIndex;
                 static constexpr std::size_t AlternativeCount = sizeof...(Ts);
 
-                VariantImpl()
+                VariantImpl() noexcept(isFirstAlternativeNothrowDefaultConstructible)
                 {
                     using FirstAlternative = typename ThisVariantAlternative<0>::type;
                     new (m_storage) FirstAlternative();
@@ -669,16 +674,11 @@ namespace Aws
             using EnableIfOtherIsThisVariantAlternative = typename std::
                 enable_if<VariantDetail::Checker::HasType<typename std::decay<OtherT>::type, Ts...>::value, int>::type;
 
-            using FirstAlternative = typename ThisVariantAlternative<0>::type;
-
-            static constexpr bool isFirstAlternativeNothrowDefaultConstructible =
-                std::is_nothrow_default_constructible<FirstAlternative>::value;
-
           public:
             using IndexT = VariantDetail::Index::VariantIndex;
             static constexpr std::size_t AlternativeCount = sizeof...(Ts);
 
-            Variant() noexcept(isFirstAlternativeNothrowDefaultConstructible) = default;
+            Variant() = default;
 
             template <typename T, EnableIfOtherIsThisVariantAlternative<T> = 1> Variant(const T &val) : m_variant(val)
             {