Problem with g++ and iostream

[Baptiste Demoulin]

Hello,

I encountered a problem today with the =g++= compiler from the 
package =gcc-toolchain=.  When compiling a simple hello world 
program:

#+begin_src c++
 #include <iostream>
 
 int main () {
   std::cout << "Hello World\n";
   return 0;
 }
#+end_src

with:
#+begin_src bash
 g++ hello.cc
#+end_src

I have the following errors, tracing back to the =iostream.h= 
file:
#+begin_example
In file included from 
/home/baptiste/.guix-profile/include/c++/bits/move.h:57,
                from 
                /home/baptiste/.guix-profile/include/c++/bits/exception_ptr.h:43,
                from 
                /home/baptiste/.guix-profile/include/c++/exception:153,
                from 
                /home/baptiste/.guix-profile/include/c++/ios:39,
                from 
                /home/baptiste/.guix-profile/include/c++/ostream:38,
                from 
                /home/baptiste/.guix-profile/include/c++/iostream:39,
                from iostream.cc:1:
/home/baptiste/.guix-profile/include/c++/type_traits:732:26: 
error: expected identifier before '(' token
 732 |     _GLIBCXX20_DEPRECATED("use is_standard_layout && 
 is_trivial instead")
     |                          ^
/home/baptiste/.guix-profile/include/c++/type_traits:732:27: 
error: expected unqualified-id before string constant
 732 |     _GLIBCXX20_DEPRECATED("use is_standard_layout && 
 is_trivial instead")
     | 
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/baptiste/.guix-profile/include/c++/type_traits:732:27: 
error: expected ')' before string constant
 732 |     _GLIBCXX20_DEPRECATED("use is_standard_layout && 
 is_trivial instead")
     | 
     ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     |                           )
/home/baptiste/.guix-profile/include/c++/type_traits:1497:12: 
error: expected identifier before '__is_nothrow_convertible'
1497 |     struct __is_nothrow_convertible
     |            ^~~~~~~~~~~~~~~~~~~~~~~~
/home/baptiste/.guix-profile/include/c++/type_traits:1497:12: 
error: expected unqualified-id before '__is_nothrow_convertible'
/home/baptiste/.guix-profile/include/c++/type_traits:3058:66: 
error: template argument 2 is invalid
3058 |             __is_nothrow_convertible<typename 
_Result::type, _Ret>>
     | 
     ^~
/home/baptiste/.guix-profile/include/c++/type_traits:3153:25: 
error: expected unqualified-id before string constant
3153 |   _GLIBCXX20_DEPRECATED("use is_standard_layout_v && 
is_trivial_v instead")
     | 
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/baptiste/.guix-profile/include/c++/type_traits:3153:25: 
error: expected ')' before string constant
3153 |   _GLIBCXX20_DEPRECATED("use is_standard_layout_v && 
is_trivial_v instead")
     | 
     ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     |                         )
#+end_example

Is it a bug, or am I doing something wrong here ?

Thanks a lot for your help !

bests,

baptiste



--
Baptiste Demoulin <baptiste.demoulin@univ-amu.fr>
Research Engineer (Ingénieur de Recherche, CNRS)
Centre Interdisciplinaire de Nanoscience de Marseille (CINaM)
Département Théorie et Simulation Numérique
Campus de Luminy – Case 913
13288 MARSEILLE Cedex 09