Question

我有以下代码：

//test.cpp
#include <Physical_file.h>
#include <boost\python.hpp>

using namespace boost::python;
using namespace FMS_Physical;


BOOST_PYTHON_MODULE(python_bridge)
{
    class_<Physical_file>("pf")
        .def("pcreate", &Physical_file::pcreate)
    ;
}

//physical_file.h
#include <fstream>
#include "tools.h"
using namespace std;

#define FMS_lvl0_DLL_API __declspec(dllexport) 

namespace FMS_Physical
{
    const int BLOCK_OFFSET = 20 + 4;
    const string SUFFIX(".hash");

    struct block
    {
        unsigned int BlockNr;
        char filler[20];
        char data[1024 - BLOCK_OFFSET];
    };

    class Physical_file
    {
    public:
        fstream filefl;
        string workingDir;
        string fileName;
        int fileSize;
        block currBlock;
        block FHBuffer;
        bool opened;
        string openMode;

        /************
        functions
        ************/

        FMS_lvl0_DLL_API Physical_file(void);
        FMS_lvl0_DLL_API Physical_file(string &FileName, int FileSize, string &Dir = getCurrentPath());
        FMS_lvl0_DLL_API Physical_file(string &FileName, string &Type, string &Dir = getCurrentPath());

        FMS_lvl0_DLL_API ~Physical_file(void);

        void FMS_lvl0_DLL_API pcreate(string &Name, int Size = 1000, string &Dir = getCurrentPath());
        void FMS_lvl0_DLL_API pdelete(void);
        void FMS_lvl0_DLL_API popen(string &name, string &OpenMode = string("I"), string &Dir = getCurrentPath());
        void FMS_lvl0_DLL_API pclose(void);

        void FMS_lvl0_DLL_API seekToBlock(unsigned int BlockNr);

        void FMS_lvl0_DLL_API WriteBlock(void);
        void FMS_lvl0_DLL_API ReadBlock(void);
        void FMS_lvl0_DLL_API WriteFH(void);
        void FMS_lvl0_DLL_API ReadFH(void);

    };
}

//physical_file.cpp
void Physical_file::pcreate(string &Name, int Size, string &Dir)
{
    if (Dir.compare("") == 0)
        Dir = getCurrentPath();
    string fileFullName = Dir + '\\' + Name + SUFFIX;
    this->filefl.open(fileFullName.c_str(),ios::in | ios::binary);
    if (filefl.is_open())
    {
        throw new exception((string("in function Physical_file::pcreate, file:") + fileFullName + " exists.").c_str());
    }
    try{
        this->filefl.open(fileFullName.c_str(),ios::binary | ios::out);
        this->opened = true;
        this->seekToBlock(0);
        this->currBlock.BlockNr = 0;
        for (int i = 0; i < Size; i++)
        {
            for (int j = 0; j < sizeof(currBlock.data); j++)
                this->currBlock.data[j] = 0;
            for (int j = 0; j < sizeof(currBlock.filler); j++)
                this->currBlock.filler[j] = 0;
            this->WriteBlock();
        }

        this->pclose();

        this->fileName = Name;
        this->workingDir = Dir;
        this->fileSize = Size;
    }
    catch(exception e)
    {
        throw new exception("in Physical_file::pcreate \n" + *e.what());
    }
}
Physical_file::Physical_file(void)
{
    this->fileName = string("");
    this->workingDir = string("");
    this->opened = false;
}

（还有一些代码，我认为它与问题无关）

尝试编译时出现以下错误：

error C2248: 'std::basic_ios<_Elem,_Traits>::basic_ios' : cannot access private member declared in class 'std::basic_ios<_Elem,_Traits>'

任何人都可以解释为什么会出现这个问题以及如何解决它？

（我正在使用vs2010，python27和c ++ boost libs进行编译）

文件physical_file.cpp和physical_file.h被编译为test.cpp使用的dll

Answer 1

默认情况下，Boost.Python会自动为曝光类型注册to_python次转换，例如Physical_file。因此，Boost.Python要求这些类型是可复制的。在这种情况下，Physical_file不可复制，其filefl成员的类型不可复制：fstream。

要解决此问题，请执行以下操作：

确定filefl的复制/所有权语义，并通过持有者对象进行管理。例如，boost::shared_ptr。

在公开boost::noncopyable类时，通过提供Physical_file作为模板参数来禁止自动注册python转换。

BOOST_PYTHON_MODULE(python_bridge)
{
  boost::python::class_<Physical_file, boost::noncopyable>("pf")
    .def("pcreate", &Physical_file::pcreate)
    ;
}

有关将C ++类公开给Python时的更多选项，请参阅boost::python::class_文档。

boost python无法访问ios私有项目

1 个答案: