<blockquote style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;" class="gmail_quote"><font color="navy" face="Arial" size="2"><span style="font-size: 10pt; font-family: Arial; color: navy;">what about if I have more than one memory mapped file and multiple such vectors in separate memory mapped io areas?</span></font></blockquote><div class="gmail_quote"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> <div link="blue" vlink="blue" lang="EN-US"><div> <p><font color="navy" face="Arial" size="2"><span style="font-size: 10pt; font-family: Arial; color: navy;">I think the method you're suggesting uses global variables, doesn't it <br></span></font></p></div></div></blockquote></div>No. I'm thinking about templating the allocator with a make_-style function that reutnrs an object of type T and then copying its value into the object that you're allocating. So somewhere in the allocator you'd have:<br> <br>new T(make_func())<br><br>This also won't result in the copy that it might seem to require. Most (all?) compilers will optimize it out.<br><br>Andrew Sutton<br><a href="mailto:andrew.n.sutton@gmail.com">andrew.n.sutton@gmail.com</a><br>