Re: [boost] [result_of] result template in case of ambiguity

From: Peter Dimov (pdimov_at_[hidden])
Date: 2006-07-10 14:18:14

Matt Calabrese wrote:
> On 7/10/06, Peter Dimov <pdimov_at_[hidden]> wrote:
>>
>> Instantiating the definition of result_of<Type> causes the
>> instantiation of
>> the declarations of its members, so this would imply that when its
>> nested type member is ill-formed, the definition of result_of<>
>> cannot be instantiated.
>>
>
> Yes, that's not what I'm asking. What I'm asking is should I have a
> nested type at all in the case of ambiguity? This would make
> accessing result_of< Type >::type ill-formed, however, it keeps
> result_of< Type > instantiable.

In principle, a portable program wouldn't be able to depend on the 
"instantiability" of result_of<Type> (if we're talking about the TR1 
result_of) since TR1 doesn't guarantee it. So you may as well pick whatever 
is more convenient for you, I guess.