At Mon, 13 Dec 2010 18:52:34 -0500, John Dlugosz wrote:
[1 <multipart/alternative (7bit)>] [1.1 <text/plain; us-ascii (quoted-printable)>] A couple of times I've run into the situation where a "new" C++ class is written to exactly match "legacy" C structures. At the edges where old code meets new code, you can cast one to the other in-place. For example, given a huge mess of data that includes oldstruct s1; you could write the line newclass& s2= reinterpret_cast<newclass&>(s1); because s2 is designed to exactly overlay s1.
Unless oldstruct and newclass are both POD, the above has implementation-defined behavior. The portable way to do it, if they indeed have the same layout, is newclass& s2= *static_cast<newclass*>(static_cast<void*>(&s1)); HTH, -- Dave Abrahams BoostPro Computing http://www.boostpro.com