Re: [boost] [bind][tr1] patch for more compliant placeholders

From: Daniel Walker (daniel.j.walker_at_[hidden])
Date: 2007-04-28 12:38:03

On 4/28/07, Peter Dimov <pdimov_at_[hidden]> wrote:
> Daniel Walker wrote:
>
> > One area where it could do better is in adaptability for call
> > wrappers. In TR1 3.3/3 call wrappers with weak result types (the
> > wrappers that bind must generate when the Result template parameter is
> > not explicitly used) are required be un-adaptable (no result_type
> > member) if the bound function object has no result_type member. It
> > could do better if it provided a result<> member that used result_of.
>
> std::result_of is required to do the right thing for every function object
> returned by the standard library, including the result of std::bind. It is
> not specified whether this is done via a nested result<> or via another
> mechanism.
>
> > To go one step further, if Boost provided a result_of implementation
> > using decltype in addition to a TR1 compliant result_of, Boost.Bind
> > could support perfect, generic, non-intrusive return type deduction.
>
> Every C++0x compiler is expected to implement result_of in terms of
> decltype.
>
> http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2194.pdf

Awesome, I didn't realize that had already happened. That's good news.
So, Boost would never need to maintain separate TR1 and TR1++, so to
speak ;), result_of and bind implementations. Is this highly likely to
go into the final ISO draft? It would be great if everyone got the
best possible bind as part of the standard!

Daniel