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

[paolo.carlini at oracle dot com]

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

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|libstdc++                   |c++

--- Comment #4 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-05-22 12:28:51 UTC ---
Thanks Marc. Well, now I would say it's a C++ front-end issue.

Consider the below: uncomment the seemingly unrelated VectorH3 constructor from
const Line_3&, and doesn't compile anymore.

////////////////

#include <type_traits>

template<typename _Tp>
  inline void
  swap(_Tp& __a, _Tp& __b)
  noexcept(std::is_nothrow_move_constructible<_Tp>::value) ;

template<class _T1>
  struct pair
  {
    _T1 first;

    void
    swap(pair& __p)
    noexcept(noexcept(swap(first, __p.first)));
  };

template < class R_ >
struct VectorH3
{
  typedef typename R_::RT                   RT;
  typedef typename R_::Ray_3                Ray_3;
  typedef typename R_::Line_3               Line_3;
  VectorH3() {}
  VectorH3(const Ray_3& r) ;
  // VectorH3(const Line_3& l) ;
  VectorH3(const RT& x, const RT& y, const RT& z, const RT& w) ;
};

template < class R_ >
class RayH3
{
   typedef typename R_::Vector_3             Vector_3;
   typedef pair<Vector_3>             Rep;
   Rep base;
};

template < class R_ >
struct LineC3
{
  typedef typename R_::Vector_3             Vector_3;
  typedef pair<Vector_3>             Rep;
  Rep base;
};

struct Kernel
{
    typedef double                                  RT;
    typedef VectorH3<Kernel>                        Vector_3;
    typedef LineC3<Kernel>                          Line_3;
    typedef RayH3<Kernel>                           Ray_3;
    struct Construct_vector_3
    {
    Vector_3
    operator()(const RT& x, const RT& y, const RT& z, const RT& w) const
    { return Vector_3(x, y, z, w); }
    };
};


int main()
{
  Kernel::Construct_vector_3()( 8, 2, 4, 1);
}