extern C and static data type problem with g++

llewelly@xmission.com llewelly@xmission.com
Tue Apr 27 14:33:00 GMT 2004


"Luu Vo" <vtluu@tma.com.vn> writes:

> In RH Linux 9, when compiling my C++ program with lines as below:
> 
> extern "C" struct {int x};
> static enum E{A=0, B, C};

extern "C"
{
  struct x {int x;};
  enum e{a= 0, b, c};
}

> 
> g++ said:
> 
> storage class specified for field `x'

Maybe the gcc 3.4 diagnostic is better:
extrn.cc:3: error: ISO C++ prohibits anonymous structs

> `static' can only be specified for objects and functions
> 
> Is this just the implementation of g++?

It is required by the ISO C++ standard. 

> That means I can't use static and
> extern "C" for those lines of code?
> 
> Another question: with GNU g++/gcc compiler and its C++ library, can I use
> both traditional C++ lib (e.g., classic iostream) and standard C++ lib
> (e.g., standard iostream) in my C++ program.

Any code which uses classic iostreams should be updated to use standard
    iostreams. 

GCC >= 3.0 does not support classic iostreams. "iostream.h" is just:

#include "backward_warning.h"
#include <iostream>

and some appropriate using declarations. For simple cases this is
    backward-compatible with classic iostreams, but in some cases it
    is not.

So if you tried to use 'both' you would really be using the same
    iostreams in both places.


> Are the both libraries
> implemented in glibstdc++?

No.



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