From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2008-03-28 23:40:45
AMDG
Giovanni Piero Deretta wrote:
> That is, something like this is actually possible:
>
> void foo () {
> int i =
> lambda
> // introduce formal parameter names
> [ _<class left>(),
> _<class right>()
> ]
> // now use them!
> [_<left>() + _<right>()]
> // actual parameters values
> ( 10, 20 );
> }
>
> The _<...>() looks a bit clumsy, but it might be actually usable.
>
I'd rather not use _. arg sound better.
lambda<class left, class right>(arg<left>() + arg<right>())
> Still the non-descriptive _N placeholders bother me.
> Using the named placeholder trick it would become:
>
> typedef compose<
> // introduce formal args names
> args<
> class range
> , class init
> , class op
> >
> // expression
> , fold(reverse(range), init, op)
> // function name
> > reverse_fold;
>
> With complex expressions, this could be quite a readability improvement.
> Except for confirming that the above expression does actually compile
> (at least with gcc), I have yet to try to implement it,
> but I think it should be fairly easy.
>
> Comments
Wow. This is awesome. You'd probably better reference the standard
(3.3.1/5)
since most people will look at this and be surprised to find that
it's legal. (I certainly was)
In Christ,
Steven Watanabe