Fix and close #19

All containers that used insert during loads (map, unordered_map, set, unordered_set)
now use emplace or emplace_hint and move their loaded values into position.

include/cereal/types/map.hpp

@@ -65,7 +65,7 @@ namespace cereal
         typename MapT::mapped_type value;
 
         ar( make_map_item(key, value) );
-        hint = map.insert(hint, {key, value} );
+        hint = map.emplace_hint( hint, std::move( key ), std::move( value ) );
       }
     }
   }

include/cereal/types/set.hpp

@@ -62,7 +62,7 @@ namespace cereal
         typename SetT::key_type key;
 
         ar( key );
-        hint = set.insert(hint, key );
+        hint = set.emplace_hint( hint, std::move( key ) );
       }
     }
   }

include/cereal/types/unordered_map.hpp

@@ -63,7 +63,7 @@ namespace cereal
         typename MapT::mapped_type value;
 
         ar( make_map_item(key, value) );
-        map.insert( {key, value} );
+        map.emplace( std::move( key ), std::move( value ) );
       }
     }
   }

include/cereal/types/unordered_set.hpp

@@ -62,7 +62,7 @@ namespace cereal
         typename SetT::key_type key;
 
         ar( key );
-        set.insert( key );
+        set.emplace( std::move( key ) );
       }
     }
   }

unittests.cpp

@@ -798,6 +798,55 @@ void test_map()
   }
 }
 
+template <class IArchive, class OArchive>
+void test_map_memory()
+{
+  std::random_device rd;
+  std::mt19937 gen(rd());
+
+  for(int i=0; i<100; ++i)
+  {
+    std::map<int, std::unique_ptr<int>> o_uniqueptrMap;
+    std::map<int, std::shared_ptr<int>> o_sharedptrMap;
+
+    for(int j=0; j<100; ++j)
+    {
+      o_uniqueptrMap.emplace( random_value<int>(gen), std::unique_ptr<int>( new int( random_value<int>(gen) ) ) );
+      o_sharedptrMap.emplace( random_value<int>(gen), std::make_shared<int>( random_value<int>(gen) ) );
+    }
+
+    std::ostringstream os;
+    {
+      OArchive oar(os);
+
+      oar( o_uniqueptrMap );
+      oar( o_sharedptrMap );
+    }
+
+    decltype( o_uniqueptrMap ) i_uniqueptrMap;
+    decltype( o_sharedptrMap ) i_sharedptrMap;
+
+    std::istringstream is(os.str());
+    {
+      IArchive iar(is);
+
+      iar( i_uniqueptrMap );
+      iar( i_sharedptrMap );
+    }
+
+    BOOST_CHECK_EQUAL(o_sharedptrMap.size(), i_sharedptrMap.size());
+    BOOST_CHECK_EQUAL(o_uniqueptrMap.size(), i_uniqueptrMap.size());
+
+    auto o_v_it = o_uniqueptrMap.begin();
+    auto i_v_it = i_uniqueptrMap.begin();
+    for(;o_v_it != o_uniqueptrMap.end(); ++o_v_it, ++i_v_it)
+    {
+      BOOST_CHECK_EQUAL(i_v_it->first, o_v_it->first);
+      BOOST_CHECK_EQUAL(*i_v_it->second, *o_v_it->second);
+    }
+  }
+}
+
 BOOST_AUTO_TEST_CASE( binary_map )
 {
   test_map<cereal::BinaryInputArchive, cereal::BinaryOutputArchive>();
@@ -818,6 +867,26 @@ BOOST_AUTO_TEST_CASE( json_map )
   test_map<cereal::JSONInputArchive, cereal::JSONOutputArchive>();
 }
 
+BOOST_AUTO_TEST_CASE( binary_map_memory )
+{
+  test_map_memory<cereal::BinaryInputArchive, cereal::BinaryOutputArchive>();
+}
+
+BOOST_AUTO_TEST_CASE( portable_binary_map_memory )
+{
+  test_map_memory<cereal::PortableBinaryInputArchive, cereal::PortableBinaryOutputArchive>();
+}
+
+BOOST_AUTO_TEST_CASE( xml_map_memory )
+{
+  test_map_memory<cereal::XMLInputArchive, cereal::XMLOutputArchive>();
+}
+
+BOOST_AUTO_TEST_CASE( json_map_memory )
+{
+  test_map_memory<cereal::JSONInputArchive, cereal::JSONOutputArchive>();
+}
+
 // ######################################################################
 template <class IArchive, class OArchive>
 void test_multimap()