提供常量_转_变量的适配器

/******************************************************************** file name : const2buffer.h author  :   Clark/陈泽丹 created :   2011-11-9 purpose :   提供常量"转"变量的适配器*********************************************************************/#pragma once#include <tchar.h>namespace CLK{//常量转变量template<class T>class const2buffer{public:static const2buffer c2b(const T* _pConst, const int _iLen) throw(const TCHAR*){//结果用值传递比用局部，引用， 指针,静态传出结果的作法更具安全意义try{ return const2buffer(_pConst, _iLen); }catch(const TCHAR* pError){ throw pError; }}explicit const2buffer(const T* _pConst, const int _iLen) throw(const TCHAR*): m_pBuf(NULL) {init(_pConst, _iLen);}const2buffer(const const2buffer& other) throw(const TCHAR*):m_pBuf(NULL) {//有内存操作,传参时需注意class objThis = other时出现浅拷贝问题init(other.m_pBuf, other.m_iLen);}const2buffer& operator = (const const2buffer& other) throw(const TCHAR*){//有内存操作,传参时需注意objThis = other时出现浅拷贝问题init(other.m_pBuf, other.m_iLen);return *this;}~const2buffer(){uninit();}operator T*(){return m_pBuf;}operator T(){return m_pBuf[0];}private:void init(const T* _pConst, const int _iLen){uninit();m_iLen = _iLen;m_pBuf = new T[m_iLen+1]; if( NULL == m_pBuf){TCHAR _tcsError[64];_stprintf(_tcsError,_T("Failed in const2buffer::new[%d]\n"),m_iLen);throw _tcsError;}    memset(m_pBuf,0,(m_iLen+1)*sizeof(T));memcpy(m_pBuf,_pConst,m_iLen*sizeof(T));}void uninit(){if( NULL != m_pBuf){delete[] m_pBuf;m_pBuf = NULL;}}T* m_pBuf;int m_iLen;};//单字节转双字节class a2w   {  public:  explicit a2w():buffer(0){}  explicit a2w(const char* str) throw(const TCHAR*):buffer(0)  {  try { init(str); }  catch(const TCHAR* pError){ throw pError; }  }  a2w(a2w& other) throw(const TCHAR*):buffer(0)  {   try { *this = other; }  catch(const TCHAR* pError){ throw pError; }  }  void init(const char* str) throw(const TCHAR*)  {   if( NULL != buffer)  delete[] buffer;  if(NULL != str)  {  int nLen = ::MultiByteToWideChar(CP_ACP,0,str,-1,NULL,0);  buffer = new wchar_t[nLen+1];if( NULL == buffer) {  buffer = NULL;  TCHAR _tcsError[256];  _stprintf(_tcsError,_T("Failed in a2w -> init -> new wchar_t[%d]\n"),nLen+1);  throw _tcsError;  }  memset(buffer,0,(nLen+1)*sizeof(wchar_t));    ::MultiByteToWideChar(CP_ACP,0,str,-1,buffer,nLen);  buffer[nLen] = 0;  }  }  ~a2w()   {    delete[] buffer;    }   a2w& operator=(a2w& other) throw(const TCHAR*)  {  if( NULL != buffer)  delete[] buffer;  if(NULL != other.buffer)  {  int nLen = wcslen(other.buffer);  buffer = new wchar_t[nLen+1];if( NULL == buffer) {  buffer = NULL;  TCHAR _tcsError[256];  _stprintf(_tcsError,_T("Failed in a2w::init -> new wchar_t[%d]\n"),nLen+1);  throw _tcsError;  }  memset(buffer,0,(nLen+1)*sizeof(wchar_t));    wcscpy(buffer,other.buffer);  buffer[nLen] = 0;  }  return *this;   }  operator const wchar_t*() { return buffer; }  private:  wchar_t* buffer;  };  //双字节转单字节class w2a   {  public:  explicit w2a():buffer(0){}  explicit w2a(const wchar_t* str) throw(const TCHAR*):buffer(0)  {   try { init(str); }  catch(const TCHAR* pError){ throw pError; }  }  w2a(w2a& other) throw(const TCHAR*):buffer(0)  {   try { *this = other; }  catch(const TCHAR* pError){ throw pError; }  }  void init(const wchar_t* str) throw(const TCHAR*)  {  if( NULL != buffer)  delete[] buffer;  if(NULL != str)  {  int nLen = WideCharToMultiByte(CP_ACP, 0, str, -1, NULL, 0, NULL, NULL);  buffer = new char[nLen+1]; if( NULL == buffer)  {  buffer = NULL;  TCHAR _tcsError[256];  _stprintf(_tcsError,_T("Failed in w2a::init -> new char[%d]\n"),nLen+1);  throw _tcsError;  }  memset(buffer,0,(nLen+1)*sizeof(char));    ::WideCharToMultiByte (CP_ACP, 0,str, -1,buffer , nLen, NULL,NULL);  buffer[nLen] = 0;  }  }  ~w2a() {  delete[] buffer;  }   w2a& operator=(w2a& other) throw(const TCHAR*)  {  if( NULL != buffer)  delete[] buffer;  if(NULL != other.buffer)  {  int nLen = strlen(other.buffer);  buffer = new char[nLen+1]; if( NULL == buffer)  {  buffer = NULL;  TCHAR _tcsError[256];  _stprintf(_tcsError,_T("Failed in w2a::init -> new char[%d]\n"),nLen+1);  throw _tcsError;  }  memset(buffer,0,(nLen+1)*sizeof(char));    strcpy(buffer,other.buffer);  buffer[nLen] = 0;  }  return *this;   }  operator const char*() { return buffer; }  private:  char *buffer;  };  }//测试 ------------------------------CLK::const2buffer<TCHAR> Test(){TCHAR szTemp[100];_tcscpy(szTemp,L"123456789");return CLK::const2buffer<TCHAR>(szTemp, _tcslen(szTemp));}try{const int TEMP_SIZE = 100;TCHAR tcsTemp[TEMP_SIZE];_stprintf(tcsTemp,_T("char* = %s\n"), (TCHAR*)CLK::const2buffer<TCHAR>::c2b(L"123",_tcslen(L"123")));MessageBox(tcsTemp);_stprintf(tcsTemp,_T("int = %d\n"), (int)CLK::const2buffer<int>::c2b(&TEMP_SIZE,1));MessageBox(tcsTemp);MessageBox(Test());}catch (const TCHAR* e){MessageBox(e);}//测试结果： 功能正常，无内存漏露