Re: [boost] Formal Review Request: TypeErasure

Subject: Re: [boost] Formal Review Request: TypeErasure
From: Steven Watanabe (watanabesj_at_[hidden])
Date: 2012-06-15 15:21:51

AMDG

On 06/13/2012 01:46 PM, Karsten Ahnert wrote:
> On 05/22/2012 10:34 PM, Steven Watanabe wrote:
>> I'd like to request a formal review of the
>> TypeErasure library that I've posted about
>> several times before here.
> 
> I am not sure if this has already been a topic here, but I wonder if the
> any type can be default constructible? The docs state that this is
> possible via type_erase::constructible< _self() >, but it is not
> working, at least for me.
> 

What do you want the default constructor to do?
constructible<_self()> captures the default
constructor of the stored type.  However, it
doesn't map to a default constructor of any<>
because there would be no way to know what the
contained type is.

typedef mpl::vector<..., constructible<_self()> > Concept;
T value;
any<Concept> x(value);
any<Concept> y(binding_of(x));

y contains a default constructed instance of T.

Now, as far as having a default constructor that
sets the any to a null state goes, I intended
to implement it, but forgot about it.  I should
have it in before the review, though.

In Christ,
Steven Watanabe