Hi list,

In 'classic' C++ style I have signalled optional parameters in a function with pointers that might be null (I wouldn't like to create overloads for all possible combination of existing and non-existing parameters) e.g.

// p1 is mandatory, p2, p3 and p4 are optional
void f(const Param1& p1, const Param2* p2, const Param3* p3, const Param4* p4);

And call it
Param1p1; Param2 p2; Param4 p4;
f(p1, &p2, 0, &p4);

I thought I could use boost::optional like this

void f(const Param1& p1, const boost::optional<Param2> & p2, const boost::optional<Param3> p3, const boost::optional<Param4> & p4);

And call it
Param1p1; Param2 p2; Param4 p4;
f(p1, boost::optional<Param2>(p2), boost::optional<Param3>(), boost::optional<Param4>(p4) );