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Question

我在编译包含 boost 库的 c++ 程序时遇到问题。在我更新到 Catalina 之后，在一切正常之前，问题似乎已经开始出现。

我使用通过 homebrew 安装的 boost ("brew install boost") 并使用 g++ 版本 9 als 与 homebrew 一起编译程序。

使用“g++-9 -I/usr/local/include -L/usr/local/lib -lboost_serialization test.cc”编译时，编译器可以正确找到库，但会出现以下错误。下面我包括错误消息和导致它的测试程序。

一个有趣的观察是，每次编译时，错误消息中引用为“cclgNgf3.o”的名称都会发生变化。到目前为止，我还得到了“ccmG1kWi.o”和“cc25AYXh.o”。

Undefined symbols for architecture x86_64:
  "boost::archive::text_oarchive_impl<boost::archive::text_oarchive>::save(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)", referenced from:
      void boost::archive::save_access::save_primitive<boost::archive::text_oarchive, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >(boost::archive::text_oarchive&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) in cclgNgf3.o
  "boost::archive::text_oarchive_impl<boost::archive::text_oarchive>::text_oarchive_impl(std::basic_ostream<char, std::char_traits<char> >&, unsigned int)", referenced from:
      boost::archive::text_oarchive::text_oarchive(std::basic_ostream<char, std::char_traits<char> >&, unsigned int) in cclgNgf3.o
  "boost::archive::basic_text_oprimitive<std::basic_ostream<char, std::char_traits<char> > >::~basic_text_oprimitive()", referenced from:
      boost::archive::text_oarchive_impl<boost::archive::text_oarchive>::~text_oarchive_impl() in cclgNgf3.o
      boost::archive::text_oarchive_impl<boost::archive::text_oarchive>::~text_oarchive_impl() in cclgNgf3.o
ld: symbol(s) not found for architecture x86_64
collect2: error: ld returned 1 exit status

#include <boost/archive/text_oarchive.hpp>
#include <iostream>

using namespace std;

int main(int argc, char **argv)
{
    boost::archive::text_oarchive oa{cout};
    return 0;
}

如果通过调用“g++ -lboost_serialization test.cc”使用 macOS clang 编译器进行编译可能相关，则会打印以下错误消息。

test.cc:8:32: error: no matching constructor for initialization of 'boost::archive::text_oarchive'
        boost::archive::text_oarchive oa{cout};
                                      ^
/usr/local/include/boost/archive/text_oarchive.hpp:98:28: note: candidate constructor (the implicit copy constructor) not viable: requires 1
      argument, but 0 were provided
class BOOST_SYMBOL_VISIBLE text_oarchive : 
                           ^
/usr/local/include/boost/archive/text_oarchive.hpp:102:5: note: candidate constructor not viable: requires at least argument 'os_', but no arguments
      were provided
    text_oarchive(std::ostream & os_, unsigned int flags = 0) :
    ^
test.cc:8:34: error: expected ';' at end of declaration
        boost::archive::text_oarchive oa{cout};
                                        ^
                                        ;
2 errors generated.

Answer 1

我使用 gcc 而不是 clang 手动构建了 boost，现在它可以工作了。看来brew版本是用clang构建的，所以当我尝试使用gcc构建我的项目时，我们会遇到标准库的冲突。