[OpenIndiana-discuss] weird C++ problem

[Apostolos Syropoulos]

Hello everybody,

I was trying to compile a program and one file failed to compile
with g++ 4.7.2 but it compiles with CC: Sun C++ 5.12 SunOS_i386 2011/11/16.

The following little program reproduces the error I got initially:

#include <iostream>
#include <string>
using namespace std;
    namespace KPS {
        extern "C" {
            #include <string.h> //it includes another header that eventually
        }                       // included this header.
    }
    using namespace KPS;

int main() {
  std::string x;
  string y = "abcdef";
  cout << y << endl;
}

The error I am getting follows:

yy.cpp: In function ‘int main()’:
yy.cpp:12:3: error: reference to ‘std’ is ambiguous
<built-in>:0:0: error: candidates are: namespace std { }
In file included from /usr/include/string.h:33:0,
                 from yy.cpp:6:
/usr/include/iso/string_iso.h:55:15: σφάλμα:                 namespace KPS::std { }
yy.cpp:12:3: σφάλμα: reference to ‘std’ is ambiguous
<built-in>:0:0: σφάλμα: candidates are: namespace std { }
In file included from /usr/include/string.h:33:0,
                 from yy.cpp:6:
/usr/include/iso/string_iso.h:55:15: σφάλμα:                 namespace KPS::std { }
yy.cpp:12:15: σφάλμα: expected ‘;’ before ‘x’

According to http://gcc.gnu.org/bugzilla/show_bug.cgi?id=1773
gcc 4.7.2 defines __cplusplus to be equal to 199711L. And of
course CC assumes that the value of __cplusplus is 
199711L. The line in iso/string_iso.h that makes
g++ to complain is line 55 of this file:

line 54: #if __cplusplus >= 199711L
line 55: namespace std {
line 56: #endif

Has anyone seen this thing before? 

A.S.

----------------------
Apostolos Syropoulos
Xanthi, Greece