Re: [Boost-users] [function_types] comparing arity

Subject: Re: [Boost-users] [function_types] comparing arity
From: Jeff Flinn (Jeffrey.Flinn_at_[hidden])
Date: 2012-03-02 20:55:12

Jeff Flinn wrote:
> I'm trying to come up with the condition for an enable_if condition 
> based on the function_arity of a signature. The following fails to compile:
> 
> bool z
> = boost::mpl::equal_to
> < boost::function_types::function_arity<SIG>::value
> , boost::mpl::int_<3>
>  >;

Ok this compiles:

bool z
= boost::mpl::equal_to
< typename boost::function_types::function_arity<SIG>::type
, boost::mpl::int_<3>
 >::value;

But when used in the following fails to compile:

typename enable_if
< typename boost::mpl::equal_to
   < typename boost::function_types::function_arity<SIG>::type
   , boost::mpl::int_<3>
   >::type
  , typename boost::function_types::result_type<SIG>::type
 >::type

Again, help is appreciated.

Thanks Jeff