Re: [Boost-users] Why not overloading && and || in bind?

15 Feb 2008

      On Fri, Feb 15, 2008 at 3:14 AM, Jean-Pierre Bergamin <james@ractive.ch> wrote:
...
Could there be a way to provide a function object safe_logical_and that only
 evaluates the second argument if the first one is true?
I've written something like that before as:

// warning, code typed in e-mail
template <typename F0, typename F2>
struct and_
{
   F0 first;
   F1 second;

   and_(F0 f0, F1, f1) : first(f0), second(f1) { }

   bool operator()() const
   {
      return first() && second();
   }
};

but if you needed function arguments that weren't available to be
bound at and_ construction time you'd have to do some more trickery.
This would also scale well using variadic templates.

--Michael Fawcett