[Bug c++/39452] New: G++ cannot compile local classes together with template.

[jim_king_2000 at 163 dot com]

The following code cannot be compiled by GCC 4.3.3.



#include 
#include 
#include 


using namespace std;


int main()
{
class PrintOne : unary_function
{
public:
result_type operator()(argument_type i)
{
wcout << i << L'\n';
}
};
int a[20] = {0, 0, 0, 0, 0};
for_each(a, a + 20, PrintOne());

return 0;
}



The error message is:
test.cpp:22: error: no matching function for call to `for_each(int[20], int*,
main()::PrintOne)'


If we move class PrintOne outside or do not use template function, the
compilation will succeed.


-- 
   Summary: G++ cannot compile local classes together with template.
   Product: gcc
   Version: 4.3.4
Status: UNCONFIRMED
  Severity: minor
  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=39452

[Bug c++/39452] G++ cannot compile local classes together with template.

[jim_king_2000 at 163 dot com]

--- Comment #2 from jim_king_2000 at 163 dot com  2009-03-13 10:45 ---
So, is it possible that the error message could be made more meaningful? I
spent several hours to find out what the "no matching function for call to"
refers to. Thanks.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39452

[Bug c++/39452] G++ cannot compile local classes together with template.

[jim_king_2000 at 163 dot com]

--- Comment #3 from jim_king_2000 at 163 dot com  2009-03-13 10:59 ---
And I'm still wondering which line in the C++ spec disallows the usage of local
class within the template function. Would you please figure it out?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39452

[Bug c++/39452] G++ cannot compile local classes together with template.

[jim_king_2000 at 163 dot com]

--- Comment #5 from jim_king_2000 at 163 dot com  2009-03-13 12:41 ---
Thank you very much.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39452

[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  
#include  
#include  
#include  
#include  
#include  


using namespace std; 


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


namespace 
{ 
 template 
 class destroyer : public unary_function 
 { 
 public: 
 using typename unary_function::result_type; 
  using typename unary_function::argument_type; 


 public: 
 typename unary_function::result_type operator()(typename
unary_function::argument_type pointer) 
  { 
   delete pointer; 
  } 
 }; 
} 


int main() 
{ 
 vector 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::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 ¡®::destroyer¡¯: 
../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