在测试可执行文件中使用特定类但不在生产可执行文件中使用特定类的 Boost 序列化的链接器错误

Question

我在一个C++项目中使用了Boost 1.49，OpenCV 2.3.1，CMake 2.8。

我正在使用相同的头文件构建两个可执行文件，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);
   }
}

这些是在contest.cpp文件中实现

的，例如

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;
    }
    }
}

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);
}

其中sr和ar在common.hpp中定义，例如

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

生成文件是从 CMake 配置生成的，如下所示：

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)

因此，这个故事的寓意是，contest和test-contest都是针对相同的标头和库编译和链接的。请注意，其他 Boost 库已成功链接和测试。

当谈到cmake 'Unix Makefiles' ..之后的make时，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，最奇怪的部分是，来自 OpenCV 中具有 serialize(Archive, cv::Rect_<int>, int) 或cv::Size_<int>的同一标头/库的serialize(Archive, cv::Point, int)没有错误。它们的序列化/测试功能定义几乎相同。

我正在成功链接contest.cpp文件中的这些serialize函数。我尝试在定义中用Rect_<int>替换Rect，但没有改变。我尝试在CMakeLists.txt中更改库的顺序，并将boost_serialization从末尾带到当前位置，但无济于事。

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，请参阅为什么只能在头文件中实现模板？或为什么模板类的实现和声明应位于同一头文件中？