[Boost-bugs] [Boost C++ Libraries] #11422: is_base<T, T> is broken on MSVC10 when T is not defined

Subject: [Boost-bugs] [Boost C++ Libraries] #11422: is_base<T, T> is broken on MSVC10 when T is not defined
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2015-06-26 13:23:48

#11422: is_base<T, T> is broken on MSVC10 when T is not defined
--------------------------------------+-------------------------
 Reporter:  Aleksej Lebedev <root@…>  |      Owner:  johnmaddock
     Type:  Bugs                      |     Status:  new
Milestone:  To Be Determined          |  Component:  type_traits
  Version:  Boost 1.57.0              |   Severity:  Problem
 Keywords:                            |
--------------------------------------+-------------------------
 Currently on Windows with MSVC10 boost defines BOOST_IS_BASE_OF (which is
 used in is_base_and_derived, which is used in is_base_of) as follows:

 {{{
 #define BOOST_IS_BASE_OF(T,U) (__is_base_of(T,U) && !is_same<T,U>::value)
 }}}

 But microsoft's intrinsic {{{__is_base_of}}} cannot be used with the same
 type (i.e. T = U) when it (the type) is not defined.

 When the following is compiled
 {{{
 class A;
 typedef typename boost::is_base_of<A, A>::type x;
 }}}

 you get an error message:
 {{{
 ...\include\boost\type_traits\is_base_and_derived.hpp(228) : error C2139:
 'A' : an undefined class is not allowed as an argument to compiler
 intrinsic type trait '__is_base_of'
 ...\include\boost\type_traits\is_base_of.hpp(29) : see reference to class
 template instantiation 'boost::detail::is_base_and_derived_impl<B,D>'
 being compiled
         with
         [
             B=A,
             D=A
         ]
 }}}

 The same code compiles on gcc-4.8.2 and clang-3.6.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/11422>
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