gmp 4.2.2: add #include <cstdio> in gmp.h

[mabshoff]

Richard B. Kreckel suggested in  http://gmplib.org/list-archives/gmp-bugs/2007-December/000892.html to add #include cstdio> to gmp.h:

Hi Torbjorn!

There's this line in gmp.h.

But std::FILE hasn't been defined and with a conforming C++ compiler it 
won't be unless <cstdio> has been included before <gmp.h>. Note that 
including <stdio.h> is not enough, as it doesn't define namespace std. 
So, defined(__cplusplus) and including <stdio.h> is not enough to 
guarantee that std::FILE is known to the compiler.

Apparently, the intent is to avoid including stdio.h or cstdio. Why? I 
would suggest including it.

Besides, these using declarations are considered bad practice in header 
files. It would be better defining GMP_FILE or similar to either expand 
to FILE or std::FILE and use that instead of FILE.

Cheers
   -richy.

I can only second that and we should do it per default since I have been bitten by this issue numerous times during the gcc 4.3 port. This should be during while doing #542 "get gmp-4.2.2 into SAGE". It is also related to #490 "gcc 4.3: fix gmp.h problem with "using std::FILE""

Cheers,

Michael

[mabshoff]

This has been fixed in #2929.

Cheers,

Michael