Re: [Boost-users] Can not compile a program that uses typeof package by gcc?

20 Oct 2008


      On Mon, Oct 20, 2008 at 11:14 AM, Steven Watanabe  wrote:
...
AMDG
Peng Yu wrote:
...
template 
   struct multiply_traits;
template 
   struct multiply_traits {
     typedef X<T1> result_type;
   };
The most reliable way to define multiply_traits in general is
template<class T>
T make();
template
struct multiply_traits {
  BOOST_TYPEOF_NESTED_TYPEDEF_TPL(nested, make<T1>() * make<T2>());
  typedef typename nested::type type;
};
...
Y operator*(const Y<T1> &y, const T2 &t)
You need to use BOOST_TYPEOF_TPL.
http://www.boost.org/doc/libs/1_36_0/doc/html/typeof/refe.html#typeof.typo.
Some compilers can handle this (I just tried it on msvc 9.0), but I strongly
advise using multiply_traits as defined above for portability.
Does this mean the error that I saw is not due to a GCC bug? Or it is
due to a GCC bug, but most other compilers would have the same bug so
that I have to use your way as a walkaround?

Thanks,
Peng