Exam CPP Topic 4 Question 75 Discussion

What happens when you attempt to compile and run the following code?
#include <vector>
# include <iostream>
# include <algorithm>
using namespace std;
class B { int val;
public:
B(int v=0):val(v){}
int getV() const {return val;}
operator int () const { return val;} };
ostream & operator <<(ostream & out, const B & v) { out<<v.getV(); return out;} template<class T>struct Out {
ostream & out;
Out(ostream & o): out(o){}
void operator() (const T & val ) { out<<val<<" "; } };
struct Add {
B operator()(B & a, B & b) { return a+b; } };
int main() {
B t[]={1,2,3,4,5,6,7,8,9,10};
vector<B> v1(t, t+10);
vector<B> v2(10);
transform(v1.begin(), v1.end(), v2.begin(), bind2nd(Add(),1));
for_each(v2.rbegin(), v2.rend(), Out<B>(cout));cout<<endl;
return 0;
}
Program outputs: