store and restore individual elements of vectors if the data is not densely packed in the vector

src/OpenMesh/Core/IO/SR_binary_spec.hh

@@ -347,12 +347,12 @@ struct binary< std::vector< T > > {
       for(auto v : _v)
       {
         size += binary<T>::size_of(v);
+      }
       if(_store_size)
       {
         unsigned int   N     = _v.size();
         size += binary<unsigned int>::size_of();
       }
-      }
 
       return size;
     }
@@ -370,12 +370,25 @@ struct binary< std::vector< T > > {
     if (_swap)
       bytes += std::accumulate( _v.begin(), _v.end(), static_cast<size_t>(0),
       FunctorStore<elem_type>(_os,_swap) );
-    else {
+    else
+    {
+      auto elem_size = binary<elem_type>::size_of();
+      if (elem_size != IO::UnknownSize && elem_size == sizeof(elem_type))
+      {
+        // size of all elements is known, equal, and densely packed in vector.
+        // Just store vector data
         auto bytes_of_vec = size_of(_v, false);
         bytes += bytes_of_vec;
         if (_v.size() > 0)
           _os.write( reinterpret_cast<const char*>(&_v[0]), bytes_of_vec);
       }
+      else
+      {
+        // store individual elements
+        for (const auto& v : _v)
+          bytes += binary<elem_type>::store(_os, v, _swap);
+      }
+    }
     return _os.good() ? bytes : 0;
   }
 
@@ -395,11 +408,23 @@ struct binary< std::vector< T > > {
              FunctorRestore<elem_type>(_is, _swap) );
     else
     {
+      auto elem_size = binary<elem_type>::size_of();
+      if (elem_size != IO::UnknownSize && elem_size == sizeof(elem_type))
+      {
+        // size of all elements is known, equal, and densely packed in vector.
+        // Just restore vector data
         auto bytes_of_vec = size_of(_v, false);
         bytes += bytes_of_vec;
         if (_v.size() > 0)
           _is.read( reinterpret_cast<char*>(&_v[0]), bytes_of_vec );
       }
+      else
+      {
+        // restore individual elements
+        for (auto& v : _v)
+          bytes += binary<elem_type>::restore(_is, v, _swap);
+      }
+    }
     return _is.good() ? bytes : 0;
   }
 };