diff --git a/include/jsoncons/config/compiler_support.hpp b/include/jsoncons/config/compiler_support.hpp
index 50889508a..5654f6567 100644
--- a/include/jsoncons/config/compiler_support.hpp
+++ b/include/jsoncons/config/compiler_support.hpp
@@ -43,16 +43,6 @@
 
 // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54577
 
-#if defined(__clang__)
-#  define JSONCONS_FALLTHROUGH [[clang::fallthrough]]
-#elif defined(__GNUC__) && ((__GNUC__ >= 7))
-#  define JSONCONS_FALLTHROUGH __attribute__((fallthrough))
-#elif defined (__GNUC__)
-#  define JSONCONS_FALLTHROUGH // FALLTHRU
-#else
-#  define JSONCONS_FALLTHROUGH
-#endif
-
 #if defined(__GNUC__) || defined(__clang__)
 #define JSONCONS_LIKELY(x) __builtin_expect(!!(x), 1)
 #define JSONCONS_UNLIKELY(x) __builtin_expect(!!(x), 0)
@@ -414,4 +404,17 @@ namespace jsoncons {
             JSONCONS_STR( 0 ))); }
 #endif // _DEBUG
 
+#if defined(JSONCONS_HAS_2017)
+#  define JSONCONS_FALLTHROUGH [[fallthrough]]
+#elif defined(__clang__)
+#  define JSONCONS_FALLTHROUGH [[clang::fallthrough]]
+#elif defined(__GNUC__) && ((__GNUC__ >= 7))
+#  define JSONCONS_FALLTHROUGH __attribute__((fallthrough))
+#elif defined (__GNUC__)
+#  define JSONCONS_FALLTHROUGH // FALLTHRU
+#else
+#  define JSONCONS_FALLTHROUGH
+#endif
+        
+        
 #endif // JSONCONS_COMPILER_SUPPORT_HPP
diff --git a/include/jsoncons/json_object.hpp b/include/jsoncons/json_object.hpp
index 3875d32f9..b947355b5 100644
--- a/include/jsoncons/json_object.hpp
+++ b/include/jsoncons/json_object.hpp
@@ -518,23 +518,20 @@ namespace jsoncons {
 
         void uninitialized_init(index_key_value<Json>* items, std::size_t count)
         {
-            auto first = items;
             if (count > 0)
             {
                 members_.reserve(count);
 
-                auto last = first + count;
-
-                std::sort(first, last, compare);
-                members_.emplace_back(key_type(first->name.c_str(), first->name.size(), get_allocator()), std::move(first->value));
-                auto prev_it = first;
-                for (auto it = first+1; it != last; ++it)
+                std::sort(items, items+count, compare);
+                members_.emplace_back(key_type(items[0].name.data(), items[0].name.size(), get_allocator()), std::move(items[0].value));
+                
+                for (std::size_t i = 1; i < count; ++i)
                 {
-                    if (it->name != prev_it->name)
+                    auto& item = items[i];
+                    if (item.name != items[i-1].name)
                     {
-                        members_.emplace_back(key_type(it->name.c_str(), it->name.size(), get_allocator()), std::move(it->value));
+                        members_.emplace_back(key_type(item.name.data(), item.name.size(), get_allocator()), std::move(item.value));
                     }
-                    ++prev_it;
                 }
             }
         }
@@ -1318,9 +1315,11 @@ namespace jsoncons {
                 std::sort(first, last, compare2);
 
                 members_.reserve(count);
-                for (auto it = first; it != last; ++it)
+
+                //for (auto it = first; it != last; ++it)
+                for (std::size_t i = 0; i < count; ++i)
                 {
-                    members_.emplace_back(std::move(it->name), std::move(it->value));
+                    members_.emplace_back(std::move(first[i].name), std::move(first[i].value));
                 }
             }
         }
diff --git a/include/jsoncons/utility/heap_string.hpp b/include/jsoncons/utility/heap_string.hpp
index d89bc0871..d5eb9cb47 100644
--- a/include/jsoncons/utility/heap_string.hpp
+++ b/include/jsoncons/utility/heap_string.hpp
@@ -70,7 +70,7 @@ namespace utility {
         Extra extra() const { return this->extra_; }
 
         heap_string(Extra extra, const Allocator& alloc)
-            : heap_string_base<Extra,Allocator>(extra, alloc), p_(nullptr), length_(0), offset_(0)
+            : heap_string_base<Extra,Allocator>(extra, alloc), p_(nullptr), length_(0), offset_(0), align_pad_(0)
         {
         }
 
diff --git a/include/jsoncons_ext/jsonschema/common/validator.hpp b/include/jsoncons_ext/jsonschema/common/validator.hpp
index 1810e72e4..7a9a8464a 100644
--- a/include/jsoncons_ext/jsonschema/common/validator.hpp
+++ b/include/jsoncons_ext/jsonschema/common/validator.hpp
@@ -172,9 +172,10 @@ namespace jsonschema {
         }
         void merge(std::unordered_set<std::string>&& properties)
         {
-            for (auto&& name : properties)
+            auto end = std::make_move_iterator(properties.end());
+            for (auto it = std::make_move_iterator(properties.begin()); it != end; ++it)
             {
-                evaluated_properties.insert(std::move(name));
+                evaluated_properties.insert(*it);
             }
         }
         void merge(const range_collection& ranges)