Fix invalid type in Pointer

Fixed miloyip/rapidjson-gitbook#1

Author: miloyip

include/rapidjson/pointer.h

@@ -537,22 +537,22 @@ class GenericPointer {
     */
     ValueType& GetWithDefault(ValueType& root, const ValueType& defaultValue, typename ValueType::AllocatorType& allocator) const {
         bool alreadyExist;
-        Value& v = Create(root, allocator, &alreadyExist);
+        ValueType& v = Create(root, allocator, &alreadyExist);
         return alreadyExist ? v : v.CopyFrom(defaultValue, allocator);
     }
 
     //! Query a value in a subtree with default null-terminated string.
     ValueType& GetWithDefault(ValueType& root, const Ch* defaultValue, typename ValueType::AllocatorType& allocator) const {
         bool alreadyExist;
-        Value& v = Create(root, allocator, &alreadyExist);
+        ValueType& v = Create(root, allocator, &alreadyExist);
         return alreadyExist ? v : v.SetString(defaultValue, allocator);
     }
 
 #if RAPIDJSON_HAS_STDSTRING
     //! Query a value in a subtree with default std::basic_string.
     ValueType& GetWithDefault(ValueType& root, const std::basic_string<Ch>& defaultValue, typename ValueType::AllocatorType& allocator) const {
         bool alreadyExist;
-        Value& v = Create(root, allocator, &alreadyExist);
+        ValueType& v = Create(root, allocator, &alreadyExist);
         return alreadyExist ? v : v.SetString(defaultValue, allocator);
     }
 #endif