[boost] Re: Submission: Rational numbers

From: Beman Dawes (beman_at_[hidden])
Date: 1999-12-10 12:06:52

At 08:53 AM 12/10/99 -0600, Ed Brey wrote:

>8.  const rational operator++(int)
>    {
>	rational was(*this);
>	operator++();
>	return was;
>    }
>
>Clever variable naming in the use of "was".  I really like it.
>BTW, the postfix operators tend to always be boring code (except for
>creative variable names) that ends up just making a temporary and
>calling the prefix version.  Is there any way to add this to
>operators.hpp?

The pending update to operators.hpp from Jeremy Siek and Dave
Abrahams adds:

template <class T>
struct incrementable
{
  friend T operator++(T& x, int)
  {
    T tmp(x);
    ++x;
    return tmp;
  }
};
  
template <class T>
struct decrementable
{
  friend T operator--(T& x, int)
  {
    T tmp(x);
    --x;
    return tmp;                      
  }
};

That update will be posted as soon as we can get a test program to
compile with a certain notorious compiler (or give up on it!).

--Beman