STL & Generic Programming: STL Function Objects and Their Adaptors

Listing 2: A typical implementation of bind2nd and binder2nd

template<class BinFunc>
class binder2nd : public unary_function<
  BinFunc::first_argument_type,
  BinFunc::result_type
  > 
{
public:
  binder2nd(
    const BinFunc& func,
    const BinFunc::second_argument_type& secondArg
    ) : m_func(func), m_secondArg(secondArg) {}
  
  result_type operator()(const argument_type& first) const
  { return m_func(first, m_secondArg); }

protected:
  BinFunc m_func;
  BinFunc::second_argument_type m_secondArg;
};

template<class BinFunc, class SecondArg> inline
binder2nd<BinFunc> bind2nd(
  const BinFunc& func, 
  const SecondArg& secondArg
  )
{
  return binder2nd<BinFunc>(
    func,
    BinFunc::second_argument_type(secondArg)
    ); 
}
— End of Listing —