C++ Constructor with rvalue

gistfile1.txt

#include <iostream>

struct Foo
{
public:
  Foo(int d) : x(d) {}
  int x;
};

int main()
{
  double x = 3.14;

  Foo f( int(x) ); // does not compile!
  //Foo f( (int) x ); // OK

  std::cout << f.x << std::endl;

  return 0;
}