[boost] Re: mpl apply_if.hpp question

13 Oct 2004


      On 10/13/2004 01:47 PM, Larry Evans wrote:
...
That's probably not the problem, because with this input:
<-------------
#include <boost/mpl/eval_if.hpp>
struct A{};
struct B{};
struct C{};
typedef boost::mpl::eval_if<A,B,C>::type X;
X x;
...
-------------
compilation succeeds.
OOPS. Forgot to rm the -E flag.  The following:

<----------------
#include <boost/mpl/eval_if.hpp>
struct C
{
     static bool const value=true;
};
struct f1
{};
struct f2
{};
namespace boost{namespace mpl{

typedef  eval_if<C,f1,f2>::type X;
X x;

}}
...
----------------
gets error:
<----------------
test.cpp(12): error: class "boost::mpl::eval_if<C, f1, f2>" has no 
member "type"
   typedef  eval_if<C,f1,f2>::type X;
                              ^
----------------