Fail to run the example of 3D Surface Mesh Generation with CGAL - c++

Question

I am trying to run this example of 3D Surface Mesh Generation with CGAL. The code is:
#include <CGAL/Surface_mesh_default_triangulation_3.h>
#include <CGAL/Complex_2_in_triangulation_3.h>
#include <CGAL/make_surface_mesh.h>
#include <CGAL/Implicit_surface_3.h>
// default triangulation for Surface_mesher
typedef CGAL::Surface_mesh_default_triangulation_3 Tr;
// c2t3
typedef CGAL::Complex_2_in_triangulation_3<Tr> C2t3;
typedef Tr::Geom_traits GT;
typedef GT::Sphere_3 Sphere_3;
typedef GT::Point_3 Point_3;
typedef GT::FT FT;
typedef FT (*Function)(Point_3);
typedef CGAL::Implicit_surface_3<GT, Function> Surface_3;
FT sphere_function (Point_3 p) {
const FT x2=p.x()*p.x(), y2=p.y()*p.y(), z2=p.z()*p.z();
return x2+y2+z2-1;
}
int main() {
Tr tr; // 3D-Delaunay triangulation
C2t3 c2t3 (tr); // 2D-complex in 3D-Delaunay triangulation
// defining the surface
Surface_3 surface(sphere_function, // pointer to function
Sphere_3(CGAL::ORIGIN, 2.)); // bounding sphere
// Note that "2." above is the *squared* radius of the bounding sphere!
// defining meshing criteria
CGAL::Surface_mesh_default_criteria_3<Tr> criteria(30., // angular bound
0.1, // radius bound
0.1); // distance bound
// meshing surface
CGAL::make_surface_mesh(c2t3, surface, criteria, CGAL::Non_manifold_tag());
std::cout << "Final number of points: " << tr.number_of_vertices() << "\n";
}
The CMakeLists file contains:
# Created by the script cgal_create_CMakeLists
# This is the CMake script for compiling a set of CGAL applications.
cmake_minimum_required(VERSION 3.7)
project(_cgal)
# CGAL and its components
find_package( CGAL QUIET COMPONENTS Core )
if ( NOT CGAL_FOUND )
message(STATUS "This project requires the CGAL library, and will not be compiled.")
return()
endif()
# include helper file
include( ${CGAL_USE_FILE} )
# Boost and its components
find_package( Boost REQUIRED )
if ( NOT Boost_FOUND )
message(STATUS "This project requires the Boost library, and will not be compiled.")
return()
endif()
# Creating entries for target: out
# ############################
set(CMAKE_CXX_STANDARD 11)
set(SOURCE_FILES main.cpp)
add_executable(_cgal ${SOURCE_FILES})
add_to_cached_list( CGAL_EXECUTABLE_TARGETS _cgal )
# Link the executable to CGAL and third-party libraries
target_link_libraries(_cgal ${CGAL_LIBRARIES} ${CGAL_3RD_PARTY_LIBRARIES} )
Output of cmake:
-- The C compiler identification is GNU 7.1.0
-- The CXX compiler identification is GNU 7.1.0
-- Checking whether C compiler has -isysroot
-- Checking whether C compiler has -isysroot - yes
-- Checking whether C compiler supports OSX deployment target flag
-- Checking whether C compiler supports OSX deployment target flag - yes
-- Check for working C compiler: /usr/local/bin/gcc-7
-- Check for working C compiler: /usr/local/bin/gcc-7 -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Checking whether CXX compiler has -isysroot
-- Checking whether CXX compiler has -isysroot - yes
-- Checking whether CXX compiler supports OSX deployment target flag
-- Checking whether CXX compiler supports OSX deployment target flag - yes
-- Check for working CXX compiler: /usr/local/bin/g++-7
-- Check for working CXX compiler: /usr/local/bin/g++-7 -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Build type: Release
-- USING CXXFLAGS = ' -DNDEBUG'
-- USING EXEFLAGS = ' '
-- Targetting Unix Makefiles
-- Using /usr/local/bin/g++-7 compiler.
-- DARWIN_VERSION=16
-- Mac Leopard detected
-- Requested component: Core
-- Requested component: MPFR
-- Requested component: GMP
-- Boost version: 1.64.0
-- Configuring done
-- Generating done
However, I am getting the following error:
Scanning dependencies of target _cgal
[ 50%] Building CXX object CMakeFiles/_cgal.dir/main.cpp.o
[100%] Linking CXX executable _cgal
Undefined symbols for architecture x86_64:
"CGAL::get_mode(std::basic_ios<char, std::char_traits<char> >&)", referenced from:
std::basic_ostream<char, std::char_traits<char> >& CGAL::insert<CGAL::Epick>(std::basic_ostream<char, std::char_traits<char> >&, CGAL::Point_3<CGAL::Epick> const&, CGAL::Cartesian_tag const&) in main.cpp.o
ld: symbol(s) not found for architecture x86_64
collect2: error: ld returned 1 exit status
make[3]: *** [_cgal] Error 1
make[2]: *** [CMakeFiles/_cgal.dir/all] Error 2
make[1]: *** [CMakeFiles/_cgal.dir/rule] Error 2
make: *** [_cgal] Error 2
I would highly appreciate if you could explain me how to fix it.
UPD: This seems to be related, but do not get what packages I should add in my cmake.
UPD2: I found that it may be related to the issue of:
There are two implementations of the standard C++ library available on
OS X: libstdc++ and libc++. They are not binary compatible and libMLi3
requires libstdc++.
On 10.8 and earlier libstdc++ is chosen by default, on 10.9 libc++ is
chosen by default. To ensure compatibility with libMLi3, we need to
choose libstdc++ manually.
To do this, add -stdlib=libstdc++ to the linking command.
I modified the following line in the CMake file, but it did not help:
# Link the executable to CGAL and third-party libraries
target_link_libraries(_cgal ${CGAL_LIBRARIES} ${CGAL_3RD_PARTY_LIBRARIES} -static-libstdc++)
UPD3: I tried the solution suggested here, however it does not help
project( _cgal )
cmake_minimum_required(VERSION 2.8.10)
find_package(CGAL QUIET COMPONENTS Core )
if ( CGAL_FOUND )
include( ${CGAL_USE_FILE} )
include( CGAL_CreateSingleSourceCGALProgram )
create_single_source_cgal_program( "main.cpp" )
else()
message(STATUS "This program requires the CGAL library, and will not be compiled.")
endif()

Answer 1

The answer is: fix compiler! CGAL was installed with brew that uses clang compiler. But to compile the project I had been using g++. I should code in C++ more often :)