for_each bind2nd mem_fun vs 2005

Question

Having problems with STL under VS 2005. I am restricted to VS 2005.

class SpeedTest
{
public:
    void AddDataPair(const std::pair<std::string, double> & datum, const std::string & insertName = "");

private:
    std::map <std::string, double> _Data;
}

void SpeedTest::AddDataPair(const pair<string, double> & datum, const string & insertName)
{
    string key = insertName + '_' + datum.first;
    _Data[key] += datum.second;
}

void SpeedTest::Insert(SpeedTest * toCopy, const string & insertName)
{
    map<string, double>::iterator dataIter;
    map<string, double>::iterator beginIter = toCopy->_Data.begin();
    map<string, double>::iterator endIter = toCopy->_Data.end();

    for_each
    (
        beginIter,
        endIter,
        bind2nd(mem_fun(&INGSpeedTest::AddDataPair)(), insertName)
    );
}

I get error C2784:

'std::const_mem_fun1_t<_Result,_Ty,_Arg> std::mem_fun(Result (_thiscall _Ty::* )(_Arg) const)' :

could not deduce template argument for 'Result (_thiscall _Ty::* )(_Arg) const'

from 'void (__thiscall INGSpeedTest::* )(const std::pair<_Ty1,_Ty2> &,const std::string &)'

        with
        [
            _Ty1=std::string,
            _Ty2=double
        ]

If I replace the for_each with a for loop

for (dataIter = beginIter; 
     dataIter != endIter; 
     ++dataIter)
{
    AddDataPair(*dataIter, insertName);
}

It compiles nicely. But I would still like to know what is failing with the for_each.

Thank you very much for any time, knowledge and effort you can spare me,

Robert

Answer 1

std::mem_fun can only wrap a member function taking zero or one parameter. Yours takes two.