On 8 December 2011 01:09, Ian Lance Taylor wrote: > Jonathan Wakely <jwakely....@gmail.com> writes: > >>> Should the Cygwin header use >>> extern "C++" on those declarations even though they're inside #ifdef >>> __cplusplus, or should adaint.c not #include things inside extern "C"? >> >> You could surround them in extern "C++", linkage specifications nest. > > ...but I think it would be better for adaint.c to not #include system > header files inside extern "C".
Indeed, I sent a follow up message which the gcc list rejected because the android gmail app refuses to send plain text email. Here's what I said: Oh sorry, I missed that the question was about a /standard/ header. Not sure about that. I think it's invalid, the standard says: "Whether a name from the C standard library declared with external linkage has extern "C" or extern "C++" linkage is implementation-defined." It shouldn't be needed unless the header is quite broken, and might cause problems, as it has here. A well behaved header will put explicit extern "C++" around anything that need "C++" language linkage, to protect against such questionable behaviour from users.
