struct subproblem
{
...
virtual void solve (double& solution, double parameter)=0;
}
struct subproblem0: public subproblem
{
...
virtual void solve (double& solution, double parameter){...};
}
struct subproblem1: public subproblem
{
...
virtual void solve (double* solution, double parameter){...};
}

int main{
subproblem problem[2];
subproblem[0] = new subproblem0();
subproblem[1] = new subproblem1();
double argument0(0),
       argument1(1),
       sol0[2],
       sol1[2];
for(unsigned int i(0);i<2;++i)
    {
    problem[i]->solve( &(sol0[i]) , argument0);
    problem[i]->solve( &(sol1[i]) , argument1);
    }
return 0;
}

Arg<T1,T2> argument0(f1,f2)

template<T1,T2> solve (double* solution, Arg<T1,T2> parameter)

struct param_list_base {
  virtual double getParam(int i) const = 0;
};

template <typename ParamStorage>
struct param_list : param_list_base {
  const ParamStorage& params;
  param_list(const ParamStorage& aParams) : params(aParams) { };
  virtual double getParam(int i) const {
    return params[i];
  };
};

class subproblem {
  protected:
    virtual void solve_impl(double* sol, param_list_base* params) = 0;
  public:
    template <typename ParamStorage>
    void solve(double* sol, ParamStorage params) {
      param_list<ParamStorage> tmp(params);
      solve_impl(sol, &tmp);
    };
};