为什么不能在c ++ 0x模式下用libc ++发出clang

Question

编译此示例代码以获取boost :: program_options：http : //svn.boost.org/svn/boost/trunk/libs/program_options/example/first.cpp

...在MacOS Lion（10.7.2）上，使用随MacPorts安装的boost-1.48.0：

$ clang++ -v

Apple clang version 3.0 (tags/Apple/clang-211.12) (based on LLVM 3.0svn)

Target: x86_64-apple-darwin11.2.0

Thread model: posix

$ clang++ -std=c++0x --stdlib=libc++ -lc++ -I/opt/local/include -L/opt/local/lib -lboost_program_options first.cpp -o first

Undefined symbols for architecture x86_64:

  "boost::program_options::options_description::options_description(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, unsigned int, unsigned int)", referenced from:

      _main in cc-6QQcwm.o

  "boost::program_options::operator<<(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, boost::program_options::options_description const&)", referenced from:

      _main in cc-6QQcwm.o

  "boost::program_options::abstract_variables_map::operator[](std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&) const", referenced from:

      boost::program_options::variables_map::operator[](std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&) const in cc-6QQcwm.o

  "boost::program_options::detail::cmdline::set_additional_parser(boost::function1<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&>)", referenced from:

  

怎么了？为什么boost :: program_options和libc ++不能一起工作？