[Boost-users] enable_if for class members

Subject: [Boost-users] enable_if for class members
From: Christopher Jefferson (chris_at_[hidden])
Date: 2009-01-30 09:21:12

In a class, I want to have one member function which has different  
implementations depending on one of the template parameters. I tried  
to use enable_if

template<bool b>
struct foo
{
   typename boost::enable_if_c<b, int>::type
   get_val( )
   { return 2; }

   typename boost::disable_if_c<b, int>::type
   get_val()
   { return 3; }
};

But when I use foo in code, it doesn't work, complaning that:
  error: no type named 'type' in 'struct boost::enable_if_c<true, int>'

Am I not using enable_if in the correct way? Is there any easy way to  
do waht I'm trying to do? I used to do this by declaring an inner  
class and overloading that, but then it is necessary to pass in the  
class and the code looks very messy.

Thanks,

Chris