Merge pull request Tencent#1034 from bluehero/master

Allow Swap with ValueType

Author: miloyip

include/rapidjson/document.h

@@ -2183,6 +2183,10 @@ class GenericDocument : public GenericValue<Encoding, Allocator> {
         return *this;
     }
 
+    // Allow Swap with ValueType.
+    // Refer to Effective C++ 3rd Edition/Item 33: Avoid hiding inherited names.
+    using ValueType::Swap;
+
     //! free-standing swap function helper
     /*!
         Helper function to enable support for common swap implementation pattern based on \c std::swap:

test/unittest/documenttest.cpp

@@ -300,7 +300,14 @@ TEST(Document, Swap) {
     o.SetObject().AddMember("a", 1, a);
 
     // Swap between Document and Value
-    // d1.Swap(o); // doesn't compile
+    d1.Swap(o);
+    EXPECT_TRUE(d1.IsObject());
+    EXPECT_TRUE(o.IsArray());
+
+    d1.Swap(o);
+    EXPECT_TRUE(d1.IsArray());
+    EXPECT_TRUE(o.IsObject());
+
     o.Swap(d1);
     EXPECT_TRUE(d1.IsObject());
     EXPECT_TRUE(o.IsArray());