What I am missing?? Where is sstring????

Hi all, Where is the g++ header called "sstring"? I am using Suse 7.1 and I am not finding it. During a google search I have found a post in gcc's FAQ that says that it is there. Ok, so where it is? Stroustrup writes it must me "sstring". (Obviously I have already been looking at /usr/include/g++). What am I doing wrong? Praise