unary_function<...>::result cannot be void.

[Jim King]

Paolo Carlini-3 wrote:
> 
> Jim King wrote:
>> Thank you very much for your reply. I tried it in OpenSolaris 11, no
>> problem.
>>   
> It's a GCC bug with -g, only not a library issue. Can you file a normal
> Bugzilla PR? Otherwise, let me know and I will do it.
>> I'm so sorry that I disturb all of the users of the list. Never again. So
>> you can delete my thread.
>>   
> That in general is impossible, for the record.
>> Last question, is there any authoritative place which I can ask
>> questions?
>>   
> gcc-help? Or, if it's really about the C++ standard, comp.std.c++. In
> general, if you are unsure, filing the snippet in Bugzilla will provide
> you some sensible feedback.
> 
> Paolo.
> 
> 

I'm a new guy to open source. I don't know what is Bugzilla PR... Sorry.

If you have interest, there is another question:

This code is failed to compile, either.

#include <functional>
#include <algorithm>
#include <iostream>
#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, int>
    {
    private:
        typedef unary_function<T, int>  base_class;

    private:
        using typename base_class::result_type;
        using typename base_class::argument_type;


    public:
        typename base_class::result_type operator()(argument_type pointer)
// compile error here
        {
            delete pointer; return 0;
        }
     };
}


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 line is:
typename base_class::result_type operator()(argument_type pointer) //
compile error here

The "argument_type" is denied by the compiler which means the using
directive does not work.
        using typename base_class::result_type;
        using typename base_class::argument_type;

Next time, I'll go to comp.std.c++.

Thank you again.

Jim
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