Add stringification methods for CLR objects

include/internal/catch_tostring.h

@@ -75,6 +75,19 @@ namespace Catch {
             return convertUnknownEnumToString( value );
         }
 
+
+#if defined(_MANAGED)
+        //! Convert a CLR string to a utf8 std::string
+        template<typename T>
+        std::string clrReferenceToString( T^ ref ) {
+            if (ref == nullptr)
+                return std::string("null");
+            auto bytes = System::Text::Encoding::UTF8->GetBytes(ref->ToString());
+            cli::pin_ptr<System::Byte> p = &bytes[0];
+            return std::string(reinterpret_cast<char const *>(p), bytes->Length);
+        }
+#endif
+
     } // namespace Detail
 
 
@@ -112,6 +125,13 @@ namespace Catch {
             return ::Catch::Detail::stringify(static_cast<typename std::underlying_type<E>::type>(e));
         }
 
+#if defined(_MANAGED)
+        template <typename T>
+        std::string stringify( T^ e ) {
+            return ::Catch::StringMaker<T^>::convert(e);
+        }
+#endif
+
     } // namespace Detail
 
     // Some predefined specializations
@@ -245,6 +265,15 @@ namespace Catch {
         }
     };
 
+#if defined(_MANAGED)
+    template <typename T>
+    struct StringMaker<T^> {
+        static std::string convert( T^ ref ) {
+            return ::Catch::Detail::clrReferenceToString(ref);
+        }
+    };
+#endif
+
     namespace Detail {
         template<typename InputIterator>
         std::string rangeToString(InputIterator first, InputIterator last) {
@@ -374,6 +403,13 @@ namespace Catch {
             !std::is_same<decltype(end(std::declval<T>())), not_this_one>::value;
     };
 
+#if defined(_MANAGED) // Managed types are never ranges
+    template <typename T>
+    struct is_range<T^> {
+        static const bool value = false;
+    };
+#endif
+
     template<typename Range>
     std::string rangeToString( Range const& range ) {
         return ::Catch::Detail::rangeToString( begin( range ), end( range ) );