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

20 Oct 2008


      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.

In Christ,
Steven Watanabe