软件设计模式

PIMPL模式

不使用PIMPL编写的代码

// file CFoo 头文件
#include "FooInternalData.h"
#include "Header.h"
class CFoo
{
public:
    CFoo();
    ~CFoo();
    bool ProcessFile(const CString & csFile);
private:
    CFooInternalData    m_data;
    CHeader             m_header;
}
 
 
// file CFoo 源文件
#include "foo.h"
CFoo::CFoo()
{
}

CFoo::~CFoo()
{
}

bool CFoo::ProcessFile(const CString & csFile)
{
    //do something
    return true;
}
 
 
// main file
#include "foo.h"
int main()
{
    CFoo foo;
    foo.ProcessFile("c:\\data.bin");
    return 0;
} 

使用PIMPL模式编写的代码

// file CFoo 头文件 

//here just declare the class PIMPL to compile.
//As I use this class with a pointer, I can use this declaration
class CFoo_pimpl;
class CFoo
{
public:
    CFoo();
    ~CFoo();
    bool ProcessFile(const CString & csFile);
private:
    std::auto_ptr<CFoo_pimpl>    m_pImpl;
} 
 
 
// file CFoo 源文件
#include "FooInternalData.h"
#include "Header.h"
#include "foo.h"
//here defines PIMPl class, because it is use only in this file
class CFoo_pimpl()
{
public:
    CFoo_pimpl()
    {
    }
 
    ~CFoo_pimpl()
    {
    } 
    bool ProcessFile(const CString & csFile)
    {
        //do something
        return true;
    }
};
 
CFoo::CFoo()
:m_pImpl(new CFoo_pimpl())
{
}
 
CFoo::~CFoo()
{
    //do not have to delete, std::auto_ptr is very nice
}
 
bool CFoo::ProcessFile(const CString & csFile)
{
    //just call your PIMPL function ;-)
    return m_pImpl->ProcessFile(csFile);
}
 

// main file 
#include "foo.h"
int main()
{
    CFoo foo;
    foo.ProcessFile("c:\\data.bin");
    return 0;
}