Re: [boost] [proto] Problems with operator <<

Subject: Re: [boost] [proto] Problems with operator <<
From: John Maddock (boost.regex_at_[hidden])
Date: 2011-08-26 12:53:21

> Yes. You want:
>
>  // Match any integral terminal
>  proto::and_<
>    proto::terminal< proto::_ >,
>    proto::if_ < boost::is_integral< proto::_value >() >
>  >

That works a treat, thanks!

Now I have another question about refining those terminals, when I have:

struct big_number_grammar
  : proto::or_<
        proto::terminal<proto::_>
      , proto::plus< big_number_grammar, big_number_grammar >
      , proto::multiplies< big_number_grammar, big_number_grammar >
      , proto::minus< big_number_grammar, big_number_grammar >
      , proto::divides< big_number_grammar, big_number_grammar >
      , proto::unary_plus< big_number_grammar >
      , proto::negate< big_number_grammar >
      , proto::or_<
           proto::modulus<big_number_grammar, big_number_grammar>
         , proto::shift_left<big_number_grammar, integer_terminal>
         , proto::shift_right<big_number_grammar, integer_terminal>
         , proto::bitwise_and<big_number_grammar, big_number_grammar>
      >
    >
{};

Then the operator overloads work just fine, but if I try and refine it to:

struct big_number_grammar
  : proto::or_<
        proto::terminal<boost::math::big_number<proto::_> >
      , proto::plus< big_number_grammar, big_number_grammar >
      , proto::multiplies< big_number_grammar, big_number_grammar >
      , proto::minus< big_number_grammar, big_number_grammar >
      , proto::divides< big_number_grammar, big_number_grammar >
      , proto::unary_plus< big_number_grammar >
      , proto::negate< big_number_grammar >
      , proto::or_<
           proto::modulus<big_number_grammar, big_number_grammar>
         , proto::shift_left<big_number_grammar, integer_terminal>
         , proto::shift_right<big_number_grammar, integer_terminal>
         , proto::bitwise_and<big_number_grammar, big_number_grammar>
      >
    >
{};

Then trying to add two big_number's results in:

1>m:\data\boost\sandbox\big_number\libs\math\ide\extended_real\scrap\scrap.cpp(24): 
error C2893: Failed to specialize function template 'const 
boost::proto::detail::enable_binary<boost::proto::domainns_::deduce_domain,boost::proto::detail::not_a_grammar,boost::mpl::or_<boost::proto::is_extension<T>,boost::proto::is_extension<Right>>,boost::proto::tag::plus,const 
Left,const Right>::type boost::proto::exprns_::operator +(const Left &,const 
Right &)'
       With the following template arguments:
          'boost::math::mpf_real_50'
          'boost::math::mpf_real_50'

Where mpf_real_50 is just a typedef for "big_number<some_backend_type>".

Is there anything obvious I'm doing wrong here?  I'm using VC10 BTW, and 
big_number inherits from proto::terminal<big_number*> in case that makes any 
difference.

Thanks again, John.