CString

#pragma once

 class Cstring{
 Cstring():m_pData(new char[1]){  *m_pData='\0';}    //默认构造

 Cstring(const char *pStr):m_pData(new char[strlen(pStr)+1]){ strcpy(m_pData,pStr); }

 Cstring(const Cstring &str):m_pData(new char[str.size()+1]){strcpy(m_pData,str.m_pData);}    //赋值构造

 friend ostream& operator<<(ostream& os,Cstring& str);
 friend istream& operator>>(istream& is,Cstring& str);

 ~Cstring(){ delete [] m_pData;}  //析构
 public:
 size_t size() const
 {
 return strlen(m_pData);
 }
 Cstring & operator = ( const Cstring & other);
 Cstring & operator = ( const char * pchar);
 Cstring & operator + ( const Cstring & other);
 Cstring & operator + ( const Cstring & other) const;
 private:
      char * m_pData;
 };

 inline Cstring& Cstring ::operator =( const Cstring & other){
 if (this != &other)
{
 delete [] m_pData;
 m_pData = new char[other.size()+1];
 strcpy(m_pData,other.m_pData);
 }
 return *this;
 }

 Cstring & Cstring::operator = ( const char * pchar)
 {
 if (m_pData != NULL)
 {
 delete [] m_pData;
 }
 size_t sz = strlen(pchar);
      m_pData = new char[sz+1];
     strcpy(m_pData,pchar);
 return *this;
 }
 inline Cstring& Cstring::operator +(const Cstring & other)      //改变被加数
 {
 char * temp = m_pData;
 m_pData = new char[strlen(m_pData)+strlen(other.m_pData)+1];
 strcpy(m_pData,temp);
 delete []temp;
 strcat(m_pData,other.m_pData);
 return *this;
 }

 inline Cstring& Cstring::operator +(const Cstring & other) const    //不改变被加数
 {
     Cstring strnew();  //Cstring* pstrnew = new Cstring();
 delete [] strnew.m_pData;
 strnew.m_pData = new char[strlen(m_pData)+strlen(other.m_pData)+1];
 strcpy(strnew.m_pData,m_pData);
 strcat(strnew.m_pData,other.m_pData);
 return strnew;
 }
 ostream& Cstring::operator<<(ostream& os,Cstring& str)
 {
     os<< str.m_pData;
 return os;
 }

 istream& Cstring::operator>>(istream& is,Cstring& str)
 {
 char arrchar[100];
     is.getline(arrchar,100);
 str = arrchar;
 return is;
 }