Question

I have a class that is not a templated class, I need to add a function to this class that is a template function. The problem is that I call a function in the class that requires a string as the parameter, so I need to make a specialized version of this template so I can call this function only if the parameter is a const char* or make a conditional check inside the function to only make a call to the function if the parameter is a const char* but that does not seem to work either. Any help would be appreciated!

template<class myType> __declspec(nothrow)
std::string GetStrVal(int row, int col, myType default) {

    try {
        CheckColumnType(col, String);
    }
    catch(DatatableException e){
        return default;
    }
    return this->m_rows[row][col];
}

template<class myType> 
std::string GetStrVal(int row, const char* col, myType default) {

    unsigned int columnIndex = this->GetColumnIndex(col);
    return GetStrVal(row,columnIndex, default);
}

GetColumnIndex() only takes a const char*.

Answer 1

You don’t need to specialize anything; you can just provide an overload or two:

    template<class myType> __declspec(nothrow)
    std::string GetStrVal(int row, int col, myType default);  // template

    __declspec(nothrow)
    std::string GetStrVal(int row, int col, std::string default); // overload

    __declspec(nothrow)
    std::string GetStrVal(int row, int col, const char *default); // overload