Re: [boost] detecting a constructor with a specific signature

Subject: Re: [boost] detecting a constructor with a specific signature
From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2010-01-26 22:15:36

AMDG

Kenny Riddile wrote:
> I'm trying to create a type trait to detect the presence of a 
> constructor with a very specific signature.  Types passed to this 
> trait will *always* have a constructor of the form:
>
> T( const std::string& );
>
> but some of them will have this constructor as well:
>
> T( const std::string&, Foo& ); // Second parameter will always be a Foo&
>
> I would like to create a type trait that returns true when the second 
> constructor is present.  I can't simply do:
>
> !is_convertible<std::string, T>::value
>
> since that will return false when the second constructor is present 
> since all Ts are convertible from std::string.  Is it possible to 
> create such a trait?

As far as I know, it's impossible.

In Christ,
Steven Watanabe