在Mac OS X上用G++4.8编译Boost：：Program_Options（Mac端口）

Question

我正在尝试使用GCC4.8（通过MacPorts安装）编译boost::program_options示例之一,http://svn.boost.org/svn/boost/trunk/libs/program_options/example/first.cpp。然而，我不断得到错误：

Undefined symbols for architecture x86_64:
  "boost::program_options::to_internal(std::basic_string, std::allocator > const&)", referenced from:
      std::vector, std::allocator >, std::allocator, std::allocator > > > boost::program_options::to_internal, std::allocator > >(std::vector, std::allocator >, std::allocator, std::allocator > > > const&) in ccEWnIGV.o
  "boost::program_options::options_description::options_description(std::basic_string, std::allocator > const&, unsigned int, unsigned int)", referenced from:
      _main in ccEWnIGV.o
  "boost::program_options::invalid_option_value::invalid_option_value(std::basic_string, std::allocator > const&)", referenced from:
      void boost::program_options::validate(boost::any&, std::vector, std::allocator >, std::allocator, std::allocator > > > const&, double*, long) in ccEWnIGV.o
  "boost::program_options::error_with_option_name::error_with_option_name(std::basic_string, std::allocator > const&, std::basic_string, std::allocator > const&, std::basic_string, std::allocator > const&, int)", referenced from:
      boost::program_options::validation_error::validation_error(boost::program_options::validation_error::kind_t, std::basic_string, std::allocator > const&, std::basic_string, std::allocator > const&, int) in ccEWnIGV.o
  "boost::program_options::detail::cmdline::set_additional_parser(boost::function1, std::allocator >, std::basic_string, std::allocator > >, std::basic_string, std::allocator > const&>)", referenced from:
      boost::program_options::basic_command_line_parser::extra_parser(boost::function1, std::allocator >, std::basic_string, std::allocator > >, std::basic_string, std::allocator > const&>) in ccEWnIGV.o
  "boost::program_options::detail::cmdline::cmdline(std::vector, std::allocator >, std::allocator, std::allocator > > > const&)", referenced from:
      boost::program_options::basic_command_line_parser::basic_command_line_parser(int, char const* const*) in ccEWnIGV.o
  "boost::program_options::operator >&, boost::program_options::options_description const&)", referenced from:
      _main in ccEWnIGV.o
  "boost::program_options::abstract_variables_map::operator[](std::basic_string, std::allocator > const&) const", referenced from:
      boost::program_options::variables_map::operator[](std::basic_string, std::allocator > const&) const in ccEWnIGV.o
  "boost::program_options::error_with_option_name::substitute_placeholders(std::basic_string, std::allocator > const&) const", referenced from:
      vtable for boost::program_options::invalid_option_value in ccEWnIGV.o
      vtable for boost::program_options::validation_error in ccEWnIGV.o
etc...

boost库通过MacPorts安装，将头文件放在/opt/local/include中，将库文件放在/opt/local/lib中。使用的compile命令是：

$G++-i/opt/local/include first.cpp-l/opt/local/lib-lboost_program_options-mt

使用G++4.8（即阶乘、hermite等）编译仅标头的boost函数可以很好地工作。

我觉得奇怪的是，如果我使用LLVM-G++编译器，这个示例会进行编译：

$LLVM-g++-i/opt/local/include first.cpp-l/opt/local/lib-lboost_program_options-mt

 $ g++ -v
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/opt/local/libexec/gcc/x86_64-apple-darwin12/4.8.1/lto-wrapper
Target: x86_64-apple-darwin12
Thread model: posix
gcc version 4.8.1 (MacPorts gcc48 4.8.1_3)

 $ llvm-g++ -v
Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn)
Target: x86_64-apple-darwin13.0.0
Thread model: posix

为什么这个例子没有用GCC4.8编译？有什么想法吗？有办法解决吗？

Update：该示例还使用clang++进行编译

Answer 1

正如Shigerello已经提到的，问题在于用clang编译的boost和用gcc编译的boost不兼容。

用GCC-4.8编译boost的一个更简单的变体是只使用boost的gcc48变体：

sudo port install boost +gcc48