double F1(boost::function<double(double)> f1); // e.g. Brent's method for root-finding
class A {
public: double TwoArg?(double x, double y); void Compute(double y);};
double A::Compute(double y) {
// 2nd argument of A::TwoArg? binds to y, 1st argument remains open boost::function<double(double)> f1 = boost::bind( boost::mem_fn(&A::TwoArg?), this, _1, y); return F1(f1);}