Hi All My code is using following (code is old) include/SmDefs.h:#include <strstream.h> include/SmDefs.h: ostrstream logstream(pData, MSGLEN); I am compiling it with gcc 3.2.1.. I get the following warning /usr/local/include/c++/3.2.1/backward/backward_warning.h:32:2: warning: #warning This file includes at least one deprecated or antiquated header. Please consider using one of the 32 headers found in section 17.4.1.2 of the C++ standard. Examples include substituting the <X> header for the <X.h> header for C++ includes, or <sstream> instead of the deprecated header <strstream.h>. To disable this warning use -Wno-deprecated. Now my question is:: In latest g++, what should be used instead of strstream/ostrstream , so that code becomes correct. (I would like to have minimum changes in the code).