boost - 在测试可执行文件中使用特定类但在生产可执行文件中不使用 Boost 序列化的链接器错误

Question

我在 C++ 项目中使用 Boost 1.49、OpenCV 2.3.1、CMake 2.8。

我正在构建两个具有相同头文件的可执行文件，一个用于生产，另一个用于测试。 contest.hpp文件指定:

namespace boost
{
   namespace serialization 
   {

   template<class Archive>
   void serialize(Archive& ar, cv::Point& p, const unsigned int version);

   template<class Archive>
   void serialize(Archive& ar, cv::Rect_<int>& r, const unsigned int version);

   template<class Archive>
   void serialize(Archive& ar, cv::Size_<int>& s, const unsigned int version);
   }
}

这些在contest.cpp中实现像这样的文件

namespace boost
{
    namespace serialization
    {

    template<class Archive>
    void serialize(Archive& ar, cv::Point& p, const unsigned int version)
    {
        ar & p.x;
        ar & p.y;
    }

    template<class Archive>
    void serialize(Archive& ar, cv::Rect_<int>& r, const unsigned int version)
    {
        ar & r.x;
        ar & r.y;
        ar & r.height;
        ar & r.width;
    }

    template<class Archive>
    void serialize(Archive& ar, cv::Size_<int>& s, const unsigned int version)
    {
        ar & s.width;
        ar & s.height;
    }

    }
}

和test-contest.cpp平凡地测试这些像

    BOOST_AUTO_TEST_CASE(Serialization1)
{

Point point_write(3, 5);
{
    ofstream point_file("Point.txt");
    ar::text_oarchive point_archive(point_file);
    sr::serialize(point_archive, point_write, 0);
}
Point point_read(0, 0);
{
    ifstream point_file("Point.txt");
    ar::text_iarchive point_archive(point_file);
    sr::serialize(point_archive, point_read, 0);
}
BOOST_CHECK(point_read == point_write);


Rect rect_write(3, 5, 1, 7);
{
    ofstream rect_file("Rect.txt");
    ar::text_oarchive rect_archive(rect_file);
    sr::serialize(rect_archive, rect_write, 0);
}
Rect rect_read(0, 0, 0, 0);
{
    ifstream rect_file("Rect.txt");
    ar::text_iarchive rect_archive(rect_file);
    sr::serialize(rect_archive, rect_read, 0);
}
BOOST_CHECK((rect_read.x) == (rect_write.y) && (rect_read.y) == (rect_write.y));

Size size_write(3, 5);
{
    ofstream size_file("Size.txt");
    ar::text_oarchive size_archive(size_file);
    sr::serialize(size_archive, size_write, 0);
}
Size size_read(0, 0);
{
    ifstream size_file("Size.txt");
    ar::text_iarchive size_archive(size_file);
    sr::serialize(size_archive, size_read, 0);
}
BOOST_CHECK(size_read == size_write);
}

哪里sr和 ar在 common.hpp 中定义喜欢

namespace ar = ::boost::archive;
namespace sr = ::boost::serialization;

makefile 是从 CMake 配置生成的，例如:

link_directories(${DEPENDENCY_DIR}/libboost/lib)
link_directories(${DEPENDENCY_DIR}/libopencv/lib)

add_executable(test-contest test-contest.cpp contest.cpp)
add_executable(contest main.cpp contest.cpp)

target_link_libraries(test-contest boost_serialization opencv_core opencv_highgui opencv_imgproc boost_program_options boost_unit_test_framework boost_filesystem)

target_link_libraries(contest boost_serialization opencv_core opencv_highgui opencv_imgproc boost_program_options boost_filesystem)

所以，这个故事的寓意是，contest和 test-contest针对相同的 header 和库 进行编译和链接。请注意，其他 Boost 库已成功链接和测试。

说到make在 cmake 'Unix Makefiles' .. 之后, 对于 contest它说

[ 40%] Building CXX object CMakeFiles/contest.dir/main.cpp.o
[ 60%] Building CXX object CMakeFiles/contest.dir/contest.cpp.o
Linking CXX executable contest
[ 60%] Built target contest

但对于 test-contest

[ 80%] Building CXX object CMakeFiles/test-contest.dir/test-contest.cpp.o
[100%] Building CXX object CMakeFiles/test-contest.dir/contest.cpp.o
Linking CXX executable test-contest
CMakeFiles/test-contest.dir/test-contest.cpp.o: In function `otap::TPageImage::Serialization1::test_method()':
/home/iesahin/Repository/otapexplorer/cli/contest-2012/test-contest.cpp:119: undefined reference to `void boost::serialization::serialize<boost::archive::text_oarchive>(boost::archive::text_oarchive&, cv::Rect_<int>&, unsigned int)'
/home/iesahin/Repository/otapexplorer/cli/contest-2012/test-contest.cpp:125: undefined reference to `void boost::serialization::serialize<boost::archive::text_iarchive>(boost::archive::text_iarchive&, cv::Rect_<int>&, unsigned int)'
/home/iesahin/Repository/otapexplorer/cli/contest-2012/test-contest.cpp:133: undefined reference to `void boost::serialization::serialize<boost::archive::text_oarchive>(boost::archive::text_oarchive&, cv::Size_<int>&, unsigned int)'
/home/iesahin/Repository/otapexplorer/cli/contest-2012/test-contest.cpp:139: undefined reference to `void boost::serialization::serialize<boost::archive::text_iarchive>(boost::archive::text_iarchive&, cv::Size_<int>&, unsigned int)'
collect2: ld returned 1 exit status
make[2]: *** [test-contest] Error 1

恕我直言，最奇怪的是，serialize(Archive, cv::Point, int) 没有错误它来自 OpenCV 中与 serialize(Archive, cv::Rect_<int>, int) 相同的 header /库或 cv::Size_<int> .它们的序列化/测试函数的定义几乎相同。

我正在链接这些 serialize来自 contest.cpp 的功能归档成功。我尝试更换 Rect与 Rect_<int>在定义中，没有变化。我尝试更改 CMakeLists.txt 中库的顺序并采取了boost_serialization从头到尾到现在的地方，都无济于事。

我哪里做错了？

Answer 1

我认为您需要将三个serialize 函数的实现从contest.cpp 移动到contest.hpp。

有关原因，请参阅 Why can templates only be implemented in the header file?或 Why should the implementation and the declaration of a template class be in the same header file?