$ cat 832794.c
#include <iostream.h>

$ g++ -c 832794.c
In file included from /usr/include/c++/4.2/backward/iostream.h:31,
                 from 832794.c:1:
/usr/include/c++/4.2/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 <iostream> instead of the deprecated header <iostream.h>. To disable this warning use -Wno-deprecated.

$ gcc -c 832794.c
832794.c:1:22: error: iostream.h: No such file or directory

##</code><code>##

_01basic_t_5cd2.xs:2:22: iostream.h: No such file or directory