#include "MyStudyFile.h"
#include <crtdbg.h>
#include <boost/smart_ptr/shared_ptr.hpp>
int strlength (const char * str)
{
const char *eos = str;
while( *eos++ ) ;
return( eos - str - 1 );
}
char * strcapend (char * dst,const char * src)
{
char * cp = dst;
while( *cp )cp++;
while( *cp++ = *src++ ) ;
return( dst );
}
char * __cdecl strcopy(char * dst, const char * src)
{
char * cp = dst;
while( *cp++ = *src++ );
return( dst );
}
template<class T>
void SwapFun(T& left, T& right)
{
T temp = left;
left = right;
right = temp;
}
template<class T>
class CArry
{
typedef T ELEMENT_TYPE;
public:
CArry(const ELEMENT_TYPE* pChar, int nSize)
:m_iMaxSize(nSize), m_iCurentSize(nSize)
{
m_pVChar = new ELEMENT_TYPE[m_iMaxSize];
ELEMENT_TYPE* pStart = m_pVChar;
while (nSize --)
{
*pStart++ = *pChar++;
}
}
CArry(const ELEMENT_TYPE* pChar, int nSize, int nMaxSize)
:m_iMaxSize(nMaxSize), m_iCurentSize(nSize)
{
m_pVChar = new ELEMENT_TYPE[m_iMaxSize];
ELEMENT_TYPE* pStart = m_pVChar;
while (nSize --)
{
*pStart++ = *pChar++;
}
}
CArry& Append(const ELEMENT_TYPE* pChar, int nSize)
{
if (nSize + m_iCurentSize <= m_iMaxSize)
{
ELEMENT_TYPE* pStart = m_pVChar+ m_iCurentSize;
while(nSize --)
{
*pStart++ = *pChar++;
}
}
else
{
CArry(m_pVChar, m_iCurentSize, nSize + m_iCurentSize).Swap(this);
Append(pChar, nSize);
}
}
CArry& Assign(const int posAfter, ELEMENT_TYPE* pChar, int nSize)
{
ELEMENT_TYPE* pStart = m_pVChar + posAfter;
while(nSize --)
{
*pStart++ = *pChar++;
}
}
~CArry()
{
delete[] m_pVChar;
}
operator ELEMENT_TYPE*()
{
return m_pVChar;
}
int GetSize()
{
return m_iCurentSize;
}
private:
void Swap(CArry& other)
{
SwapFun(m_pVChar, other.m_pVChar) ;
SwapFun(m_iMaxSize, other.m_iMaxSize);
SwapFun(m_iCurentSize, other.m_iCurentSize);
}
ELEMENT_TYPE* m_pVChar;
int m_iMaxSize;
int m_iCurentSize;
};
//共享的实现。
template<class T>
class ShareDataImp
{
typedef T ElementType;
private:
struct SharedData
{
SharedData(ElementType* p = NULL):m_p(p), nRef(1)
{
}
void AddRef()
{
++ nRef;
}
void Release()
{
if (-- nRef == 0)
{
delete m_p;
m_p = NULL;
}
}
ElementType* GetPtr()
{
return m_p;
}
int GetCount()
{
return nRef;
}
private:
ElementType* m_p;
int nRef;
};
public:
ShareDataImp(ElementType* pstr = NULL)
: m_pData(new SharedData(pstr))
{
}
~ShareDataImp()
{
m_pData->Release();
if (m_pData->GetCount() == 0)
{
delete m_pData;
}
m_pData = NULL;
}
ShareDataImp(const ShareDataImp& _right)
: m_pData(_right.m_pData)
{
m_pData->AddRef();
}
//释放对共享数据的所有权。
void ResetAs(ElementType* p)
{
m_pData->Release();
delete m_pData;
m_pData = new SharedData(p);
}
ElementType* Get() const
{
return m_pData->GetPtr();
}
private:
SharedData* m_pData;
};
class CString
{
public:
CString(char* pStr)
{
CArry<char>* pArry = new CArry<char>(pStr, strlength(pStr) + 1);
m_shareData.ResetAs(pArry);
}
~CString()
{
}
const char* cstr() const
{
return *(m_shareData.Get());
}
CString& Append(CString& strVal)
{
CString strRight(strVal.cstr());
m_shareData.ResetAs(CloneData(GetLength() + strRight.GetLength() + 1));
m_shareData.Get()->Assign(GetLength(), strRight.cstr(), strRight.GetLength() + 1);
return *this;
}
CString& Append(char* pChar, int iLength)
{
m_shareData.ResetAs(CloneData(GetLength() + iLength + 1));
m_shareData.Get()->Assign(GetLength(), pChar, iLength + 1);
}
CString& Assign(const CString& strVal)
{
m_shareData.ResetAs(strVal.CloneData(strVal.GetLength() + 1));
return *this;
}
CString& Assign(char* pStr)
{
m_shareData.ResetAs(new CArry<char>(pStr, strlength(pStr) + 1));
return *this;
}
int GetLength() const
{
return m_shareData.Get()->GetSize() - 1;
}
private:
char* cstr()
{
return *(m_shareData.Get());
}
CArry<char>* CloneData(int iSize) const
{
return new CArry<char>(cstr(), GetLength() + 1, iSize);
}
ShareDataImp<CArry<char>> m_shareData;
};
int main()
{
CString* pVal = new CString("121312");
CString* pVa2 = new CString(*pVal);
CString* pVa3 = new CString(*pVa2);
CString* pVa4 = new CString(*pVa3);
delete pVal;
delete pVa2;
delete pVa3;
delete pVa4;
_CrtDumpMemoryLeaks();
}
