[Bug c++/49107] [C++0x][4.7 Regression] incomplete type regression with std::pair

["marc.glisse at normalesup dot org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49107

--- Comment #20 from Marc Glisse <marc.glisse at normalesup dot org> 2011-06-10 20:39:59 UTC ---
The patch fixes the example (thanks), but I still have trouble with the
following (and I also get a different type of failure elsewhere that I'll
investigate later):

#include <utility>

template <class R_>
struct Vector3
{
        typedef typename R_::Ray_3                 Ray_3;
        Vector3() {}
        explicit Vector3(const Ray_3& r);
};

template < class R_ > class LineC3
{
        typedef typename R_::Vector_3             Vector_3;
        std::pair<int, Vector_3> x;
};

template < class R_ > class RayH3
{
        typedef typename R_::Vector_3             Vector_3;
        std::pair<int, Vector_3> x;
};

template <typename Kernel >
struct Homogeneous_base
{
        typedef LineC3<Kernel>                          Line_3;
        typedef RayH3<Kernel>                           Ray_3;
};

template < typename RT_>
struct Simple_homogeneous
: public Homogeneous_base< Simple_homogeneous<RT_> >
{
        typedef Vector3<Simple_homogeneous<RT_> > Vector_3;
};

int main()
{
        typedef   Simple_homogeneous<double>     R;
        R::Line_3 l3;
}




which fails with:
In file included from
/tmp/gcc/inst/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/../../../../include/c++/4.7.0/utility:72:0,
                 from Simple_homogeneous.cpp:1:
/tmp/gcc/inst/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/../../../../include/c++/4.7.0/bits/stl_pair.h:
In constructor 'std::pair<_T1, _T2>::pair(std::pair<_T1, _T2>&&) [with _T1 =
int, _T2 = Vector3<Simple_homogeneous<double> >, std::pair<_T1, _T2> =
std::pair<int, Vector3<Simple_homogeneous<double> > >]':
/tmp/gcc/inst/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/../../../../include/c++/4.7.0/type_traits:740:46:
  required from 'struct
std::__is_direct_constructible_impl<Vector3<Simple_homogeneous<double> >,
Vector3<Simple_homogeneous<double> >&&>'
/tmp/gcc/inst/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/../../../../include/c++/4.7.0/type_traits:89:12:
  required from 'struct
std::__and_<std::is_destructible<Vector3<Simple_homogeneous<double> > >,
std::__is_direct_constructible_impl<Vector3<Simple_homogeneous<double> >,
Vector3<Simple_homogeneous<double> >&&> >'
/tmp/gcc/inst/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/../../../../include/c++/4.7.0/type_traits:744:12:
  required from 'struct
std::__is_direct_constructible_new_safe<Vector3<Simple_homogeneous<double> >,
Vector3<Simple_homogeneous<double> >&&>'
/tmp/gcc/inst/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/../../../../include/c++/4.7.0/type_traits:816:12:
  required from 'struct
std::__is_direct_constructible_new<Vector3<Simple_homogeneous<double> >,
Vector3<Simple_homogeneous<double> >&&>'
/tmp/gcc/inst/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/../../../../include/c++/4.7.0/type_traits:824:12:
  required from 'struct
std::__is_direct_constructible<Vector3<Simple_homogeneous<double> >,
Vector3<Simple_homogeneous<double> >&&>'
/tmp/gcc/inst/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/../../../../include/c++/4.7.0/type_traits:863:12:
  [ skipping 3 instantiation contexts ]
/tmp/gcc/inst/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/../../../../include/c++/4.7.0/type_traits:960:12:
  required from 'struct
std::is_nothrow_constructible<Vector3<Simple_homogeneous<double> >,
Vector3<Simple_homogeneous<double> >&&>'
/tmp/gcc/inst/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/../../../../include/c++/4.7.0/type_traits:991:12:
  required from 'struct
std::__is_nothrow_move_constructible_impl<Vector3<Simple_homogeneous<double> >,
false>'
/tmp/gcc/inst/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/../../../../include/c++/4.7.0/type_traits:997:12:
  required from 'struct
std::is_nothrow_move_constructible<Vector3<Simple_homogeneous<double> > >'
/tmp/gcc/inst/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/../../../../include/c++/4.7.0/type_traits:89:12:
  required from 'struct std::__and_<std::is_nothrow_move_constructible<int>,
std::is_nothrow_move_constructible<Vector3<Simple_homogeneous<double> > > >'
/tmp/gcc/inst/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/../../../../include/c++/4.7.0/bits/stl_pair.h:122:7:
  required from 'std::pair<_T1, _T2>::pair(std::pair<_T1, _T2>&&) [with _T1 =
int, _T2 = Vector3<Simple_homogeneous<double> >, std::pair<_T1, _T2> =
std::pair<int, Vector3<Simple_homogeneous<double> > >]'
Simple_homogeneous.cpp:40:12:   required from here
/tmp/gcc/inst/lib/gcc/x86_64-unknown-linux-gnu/4.7.0/../../../../include/c++/4.7.0/bits/stl_pair.h:122:7:
error: incomplete type 'std::__and_<std::is_nothrow_move_constructible<int>,
std::is_nothrow_move_constructible<Vector3<Simple_homogeneous<double> > > >'
used in nested name specifier