View Compilation Error

0_0_18828947_28595.cpp: In function 'int main()':
0_0_18828947_28595.cpp:58:8: error: reference to 'extent' is ambiguous
   news=extent(s,tmp);
        ^
0_0_18828947_28595.cpp:25:7: note: candidates are: Point extent(Point, Point)
 Point extent(Point a,Point b)
       ^
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/move.h:57:0,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_pair.h:59,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/utility:70,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/algorithm:60,
                 from 0_0_18828947_28595.cpp:2:
GCC4.9.2/x86_64-w64-mingw32/include/c++/type_traits:693:12: note:                 template<class, unsigned int <anonymous> > struct std::extent
     struct extent;
            ^