//str.h#include<iostream>#ifndef _STR_H#define _STR_H
class CStr...{
public: CStr(); CStr(const char*); CStr(int,char); CStr(const CStr&); ~CStr();public: const char* c_str(); int length();public: char& operator[](int); bool operator==(CStr&); CStr& operator=(const CStr&); const CStr operator+(const CStr&); const CStr& operator+=(const CStr&); friend std::ostream& operator<<(std::ostream&,CStr&); friend std::istream& operator>>(std::istream&,CStr&);private: char *m_str; int m_len;
};#endif这个字符串类包含了一些最基本的东西，下面是各个成员函数及重载操作符的实现：
#include"str.h"CStr::CStr():m_str(NULL),m_len(0)...{}CStr::CStr(const char *p)...{ int size=0; const char *t=p; while(*t++) ++size; m_str=new char[size+1]; m_len=size; memcpy(m_str,p,size+1);}CStr::CStr(int n,char ch)...{ m_len=n; m_str=new char[m_len+1]; m_str[m_len]=0; memset(m_str,ch,m_len);}CStr::CStr(const CStr &s)...{ m_str=new char[s.m_len+1]; m_len=s.m_len; memcpy(m_str,s.m_str,m_len+1);}CStr::~CStr()...{ if(m_str) delete[] m_str; }const char* CStr::c_str()...{ return m_str;}bool CStr::operator==(CStr &s)...{
for(int i=0;i!=m_len;++i)...{ if(*(m_str+i)!=*(s.m_str+i)) return false;
} return true;}CStr& CStr::operator=(const CStr &s)...{ if(this==&s) return *this; delete[] m_str; m_len=s.m_len; m_str=new char[m_len+1]; memcpy(m_str,s.m_str,m_len+1); return *this; }const CStr CStr::operator+(const CStr &s)...{ char *p=new char[m_len+s.m_len+1]; memcpy(p,m_str,m_len); memcpy(p+m_len,s.m_str,s.m_len+1); CStr str(p); delete[] p; return str;}std::ostream& operator<<(std::ostream &out,CStr &s)...{ out<<s.m_str; return out;}std::istream& operator>>(std::istream &in,CStr &s)...{ if(s.m_str)...{ delete[] s.m_str; s.m_len=0; } char buf[1024]; in>>buf; while(buf[s.m_len])...{ ++s.m_len; } s.m_str=new char[s.m_len+1]; memcpy(s.m_str,buf,s.m_len+1); return in;}char& CStr::operator[](int n)...{ return m_str[n];}const CStr& CStr::operator+=(const CStr &s)...{ *this=*this+s; return *this;}