From: Doug Gregor (dgregor_at_[hidden])
Date: 2004-11-22 19:15:35
On Nov 22, 2004, at 7:05 PM, Brock Peabody wrote:
> I replaced my home grown result_type<> with boost::result_of<> today
> only to
> find that I couldn't get it to work. When I try to use result_of with
> VC
> 7.1:
>
> struct test_struct {
>
> typedef int result_type;
> };
>
> boost::result_of<test_struct>::type i = 5;
>
> I get:
>
> test.cpp(10) : error C2027: use of undefined type
> 'boost::result_of<F>'
>
> I get the same results if I use function types of pointer to function
> types:
>
> boost::result_of<int (*)()>::type i = 5;
> boost::result_of<int ()()>::type i = 5;
>
> Am I missing something?
Yes :)
With result_of, you pass the function object type _and_ the types of
the arguments, e.g.,
boost::result_of<test_struct(int, float)>::type
That's how result_of is able to deal with polymorphic function objects.
Doug