CGAL users discussion list

[Philipp Moeller <>]

sebitas 
<>
 writes:

>  Hello I installed cgal with macports and I was triying to run this example 
> I
> found: 
> #include <iostream>
>
> #include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
> #include <CGAL/convex_hull_2.h>
>
> typedef CGAL::Exact_predicates_inexact_constructions_kernel K; 
> typedef K::Point_2 Point_2; 
>
> int main() 
> { 
>     Point_2 points[5] = { Point_2(0,0), Point_2(10,0), Point_2(10,10),
> Point_2(6,5), Point_2(4,1) }; 
>     Point_2 result[5]; 
>     
>     Point_2 *ptr = CGAL::convex_hull_2( points, points+5, result ); 
>     std::cout <<  ptr - result << " points on the convex hull" << 
> std::endl; 
>     return 0; 
> } 
>
> Nevertheless I get this linking errors .I am using xcode 4.3.2 and os 10.7.4
> . Regards 
>
> Undefined symbols for architecture x86_64: 
>   "___gmpq_init", referenced from: 
>       CGAL::Gmpq_rep::Gmpq_rep()in main.o 
>   "___gmpq_clear", referenced from: 
>       CGAL::Gmpq_rep::~Gmpq_rep()in main.o 
>   "___gmpq_set_d", referenced from: 
>       CGAL::Gmpq::Gmpq(double)in main.o 
>   "___gmpq_sub", referenced from: 
>       CGAL::Gmpq::operator-=(CGAL::Gmpq const&)in main.o 
>   "___gmpq_mul", referenced from: 
>       CGAL::Gmpq::operator*=(CGAL::Gmpq const&)in main.o 
>   "___gmpq_cmp", referenced from: 
>       CGAL::Gmpq::operator<(CGAL::Gmpq const&) constin main.o 
>   "___gmpq_equal", referenced from: 
>       CGAL::Gmpq::operator==(CGAL::Gmpq const&) constin main.o 
> ld: symbol(s) not found for architecture x86_64 
> collect2: ld returned 1 exit status 

You are not linking to GMP although macports ships a gmp enabled CGAL
installation. To add an additional library within XCode:
  Go to Project -> Edit Project -> Linking -> Other Linker Flags

and add -L/path/to/gmp/lib/ -lgmp