[Bug libstdc++/59087] including complex.h in C++11/1y mode should not include C's complex.h

[kikairoya at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59087

--- Comment #2 from Tomohiro Kashiwada <kikairoya at gmail dot com> ---
C's <complex.h> provides a macro named 'I' and this breaks existing codes.

ext/pod_char_traits.h
gcc4.8.2) http://melpon.org/wandbox/permlink/qb87YqrI7I4BAQRw
gcc4.7.3) http://melpon.org/wandbox/permlink/ighn7hGeL2tFXj16

boost/iterator/iterator_facade.hpp
gcc4.8.2) http://melpon.org/wandbox/permlink/VERBb6mK69nva2ML
gcc4.7.3) http://melpon.org/wandbox/permlink/ujalJUbClOd9FjFg


and, anyway, C's complex doesn't work on C++11 mode.
gcc4.8.2 c++11) http://melpon.org/wandbox/permlink/CnsddYRxUohlCGF1
gcc4.8.2 c++03) http://melpon.org/wandbox/permlink/QrBInjH6rlRs2Jdl


Or, if C++'s <complex.h> includes C's one, I think also <ccomplex> should
behave so (I think 26.4.10 is incomprehensible.)