The deserialize() for std::string was written under the assumption that std::string

doesn't store it's data in a contiguous block.  However, that isn't quite the case.
See this discussion:
http://stackoverflow.com/questions/1986966/does-s0-point-to-contiguous-characters-in-a-stdstring

Anyway, I changed deserialize() for std::string to be more efficient and read
directly into the string rather than into a contiguous buffer and then do a copy.

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%404235

dlib/serialize.h

@@ -745,27 +745,16 @@ namespace dlib
         std::istream& in
     )
     {
-        char* buf = 0;
-        try
+        unsigned long size;
+        try { deserialize(size,in); }
+        catch (serialization_error& e)
+        { throw serialization_error(e.info + "\n   while deserializing object of type std::string"); }
+
+        item.resize(size);
+        if (size != 0)
         {
-            unsigned long size;
-            try { deserialize(size,in); }
-            catch (serialization_error& e)
-            { throw serialization_error(e.info + "\n   while deserializing object of type std::string"); }
-
-            buf = new char[size+1];
-            buf[size] = 0;            
-            in.read(buf,size);
-            item.assign(buf);
+            in.read(&item[0],size);
             if (!in) throw serialization_error("Error deserializing object of type std::string");
-            delete [] buf;
-        }
-        catch (...)
-        {
-            if (buf)
-                delete [] buf;
-            item.erase();
-            throw;
         }
     }