cygwinのgccなんですが、
#include <iostream.h>

int main()
{
return 0;
}
こんな簡単なプログラムを書いて
g++ hoge.cpp
とコンパイルすると
In file included from /usr/include/c++/3.2/backward/iostream.h:31,
from hoge.cpp:1:
/usr/include/c++/3.2/backward/backward_warning.h:32:2: warning:
#warning This file includes at least one deprecated or antiquated header.
Please consider using one of the 32 headers found in section 17.4.1.2 of
the C++ standard. Examples include substituting the <X> header for the
<X.h> header for C++ includes, or <sstream> instead of the deprecated
header <strstream.h>. To disable this warning use -Wno-deprecated.
こういうエラーが出てきます。原因をご存知の方いませんか。