[Bug c++/39680] New: unary_function<...>::result_type cannot be void.

[jim_king_2000 at 163 dot com]

Hi everyone 

The following code cannot pass compilation by g++ v4.3.2.


#include <functional> 
#include <algorithm> 
#include <iostream> 
#include <string> 
#include <memory> 
#include <vector> 


using namespace std; 


class test 
{ 
public: 
 void func(int i) { wcout << i << L": test\n"; } 
}; 


namespace 
{ 
 template<class T> 
 class destroyer : public unary_function<T, void> 
 { 
 public: 
         using typename unary_function<T, void>::result_type; 
  using typename unary_function<T, void>::argument_type; 


 public: 
         typename unary_function<T, void>::result_type operator()(typename
unary_function<T, void>::argument_type pointer) 
  { 
   delete pointer; 
  } 
 }; 
} 


int main() 
{ 
 vector<test *> data; 

 for (int i = 0; i < 5; ++i) 
  data.push_back(new test); 

 for_each(data.begin(), data.end(), bind2nd(mem_fun(&test::func), 0)); 

 for_each(data.begin(), data.end(), destroyer<vector<test *>::value_type>()); 

    return 0; 
} 


The error message is quite vague:
g++ -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"src/Test_Cplusplus.d"
-MT"src/Test_Cplusplus.d" -o"src/Test_Cplusplus.o" "../src/Test_Cplusplus.cpp" 
../src/Test_Cplusplus.cpp: In instantiation of ¡®<unnamed>::destroyer<test*>¡¯: 
../src/Test_Cplusplus.cpp:49:   instantiated from here 
../src/Test_Cplusplus.cpp:25: internal compiler error: in
dwarf2out_imported_module_or_decl, at dwarf2out.c:14261 
Please submit a full bug report, 
with preprocessed source if appropriate. 
See <http://bugs.opensuse.org/> for instructions. 
make: *** [src/Test_Cplusplus.o] error 1

However, if the "result_type" is not void, the code can be compiled
successfully. Does this behavior conform to the standard?


-- 
           Summary: unary_function<...>::result_type cannot be void.
           Product: gcc
           Version: 4.3.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: jim_king_2000 at 163 dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39680