Справочное руководство по C++

Страустрап Бьярн

{

 for (int i=0; i‹free; i++)

cout ‹‹ vec[i].name ‹‹ ": " ‹‹ vec[i].val ‹‹ "\n";

}

main

{

 const MAX = 256;

 char buf[MAX];

 assoc vec(512);

 while (cin››buf) vec[buf]++;

 vec.print_all;

}

b6_8.cxx

#include ‹stream.hxx›

#include ‹string.h›

struct pair {

 char* name;

 int val;

};

class assoc {

 friend class assoc_iterator;

 pair* vec;

 int max;

 int free;

public:

 assoc(int);

 int& operator[](char*);

};

class assoc_iterator {

 assoc* cs;

 int i;

public:

 assoc_iterator(assoc& s) { cs =&s; i = 0; }

 pair* operator

 { return (i‹cs-›free) ? &cs-›vec[i++] : 0; }

};

assoc::assoc(int s)

{

 max = (s‹16) ? s : 16;

 free = 0;

 vec = new pair[max];

}

int& assoc::operator[](char* p)

{

 register pair* pp;

 for (pp = &vec[free-1]; vec‹=pp; pp--)

if (strcmp(p,pp-›name)==0) return pp-›val;

 if (free == max) {

pair* nvec = new pair[max*2];

for (int i=0; i‹max; i++) nvec[i] = vec[i];

delete vec;

vec = nvec;

max = 2*max;

 }

 pp =&vec[free++];

 pp-›name = new char[strlen(p)+1];

 strcpy(pp-›name,p);

 pp-›val = 0;

 return pp-›val;

}

main

{

 const MAX = 256;

 char buf[MAX];

 assoc vec(512);

 while (cin››buf) vec[buf]++;

 assoc_iterator next(vec);

 pair* p;

 while (p = next)

cout ‹‹ p-›name ‹‹ ": " ‹‹ p-›val ‹‹ "\n";

}

b6_9.cxx

#include ‹stream.hxx›

#include ‹string.h›

extern void exit(int);

class string {

 struct srep {

char* s;

int n;

 };

 srep *p;

public:

 string(char *);

 string;

 string(string&);

 string& operator=(char *);

 string& operator=(string&);

 ~string;

 char& operator[](int i);

 friend ostream& operator‹‹(ostream&, string&);

 friend istream& operator››(istream&, string&);

 friend int operator==(string&x, char *s)

{ return strcmp(x.p-›s, s) == 0; }

 friend int operator==(string&x, string&y)

{ return strcmp(x.p-›s, y.p-›s) == 0; }

 friend int operator!=(string&x, char *s)

{return strcmp(x.p-›s, s) != 0;}

 friend int operator!=(string&x, string&y)

{return strcmp (x.p-›s, y.p-›s) != 0;}

};

string::string

{

 p = new srep;

 p-›s = 0;

 p-›n = 1;

}

string::string(char* s)

{

 p = new srep;

 p-›s = new char[strlen(s) +1];

 strcpy(p-›s, s);

 p-›n = 1;

}

string::string(string& x)

{

 x.p-›n++;

 p = x.p;

}

string::~string

{

 if (--p-›n - 0) {

delete p-›s;

delete p;

 }

}

string& string::operator=(char* s)