Using function non-member of class inside this class

[Stas Kubrak]

Hello, here some problem with using function NOT a member of class:

double function (double (*fun) (double),double a) 
{
	
    return (*fun)(a);
}

class SomeClass
{
   private:
   double x;

   public:
   double M;

   double M_func (double y)
   {
       return y*y;
   }

   void set_M()
   {
       M=function(&M_func,x);
   }
}

the error - 49:40: error: cannot convert ‘double (SomeClass::*)(double, double)’ to ‘double (*)(double, double)’

i know it`s looks strange to set M like that, but in my real code i have to.

How to make it right?

[Gaminic]

It does really look weird. What's keeping you from simply doing M = M_func(x);?

[Peter87]

normal functions and member functions are two different things so you can't treat them the same.
Maybe you want to make M_func a static function?