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

3 Mar 2012

      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