Re: [Boost-users] Boost Phoenix Arguments Passing & Storage (-- Proper Type?) & Application to RValues -- Possible?

Subject: Re: [Boost-users] Boost Phoenix Arguments Passing & Storage (-- Proper Type?) & Application to RValues -- Possible?
From: Matt (matdzb_at_[hidden])
Date: 2012-02-15 12:33:55

On 2/15/2012 03:57, Mathias Gaunard wrote:
> You're using Phoenix v2, which doesn't support rvalues and also has
> many type deduction problems. Try v3.

Thanks!

Upgrading to Version 1.49.0 beta 1 fixed the Application-to-RValues part.

Now, to the proper-type-name for passing & storage part.

I've tried the following and it works:

auto newActor() -> decltype((arg1 % 2 == 1))
{
        return (arg1 % n == 0);
}

auto f = (arg1 % 2 == 1);
auto g = f;
g = newActor();

I can find out the type name using non-portable typeid(Variable).name(),
but the output is somewhat inconvenient (quoted below).

Is there a nice-to-type solution?
It'd be esp. useful for non-C++11 compiler, where I cannot use 
trailing-return-type for "newActor" function nor type deduction for "f" 
and "g" variables -- what's the suggested type in this situation?

I've realized that using boost::function (or std::function) won't work 
either, since it's monomorphic (while one of the reasons I'm looking at 
Boost.Phoenix is polymorphic lambdas).

Type name:

struct boost::phoenix::actor
<
   struct boost::proto::exprns_::basic_expr
   <
     struct boost::proto::tagns_::tag::equal_to,
     struct boost::proto::argsns_::list2
     <
       struct boost::phoenix::actor
       <
         struct boost::proto::exprns_::basic_expr
         <
           struct boost::proto::tagns_::tag::modulus,
           struct boost::proto::argsns_::list2
           <
             struct boost::phoenix::actor
             <
               struct boost::proto::exprns_::basic_expr
               <
                 struct boost::proto::tagns_::tag::terminal,
                 struct boost::proto::argsns_::term
                 <
                   struct boost::phoenix::argument<1>
                 >,
                 0
               >
             >,
             struct boost::phoenix::actor
             <
               struct boost::proto::exprns_::basic_expr
               <
                 struct boost::proto::tagns_::tag::terminal,
                 struct boost::proto::argsns_::term<int>, 0
               >
             >
           >,
           2
         >
       >,
       struct boost::phoenix::actor
       <
         struct boost::proto::exprns_::basic_expr
         <
           struct boost::proto::tagns_::tag::terminal,
           struct boost::proto::argsns_::term<int>, 0
         >
       >
     >,
     2
   >
 >

Best,

Matt