hedgezzz的部落格

http://www.parashift.com/c++-faq-lite/calling-virtuals-from-ctors.html

#include <iostream>
#include <string>

void println(std::string const& msg)
{ std::cout << msg << '\n'; }

class Base {
public:
  Base()              { println("Base::Base()");  virt(); }
  virtual void virt() { println("Base::virt()"); }
};

class Derived : public Base {
public:
  Derived()           { println("Derived::Derived()");  virt(); }
  virtual void virt() { println("Derived::virt()"); }
};

int main()
{
  Derived d;
}