一个计时器的实现
直接上代码
定义头文件：
//: C09:Cpptime.h
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 2000
// Copyright notice in Copyright.txt
// A simple time class
#ifndef CPPTIME_H
#define CPPTIME_H
#include <ctime>
#include <cstring>
class Time {
time_t t;
tm local;
char asciiRep[26];
unsigned char lflag, aflag;
void updateLocal() {
if(!lflag) {
local = *localtime(&t);
lflag++;
}
}
void updateAscii() {
if(!aflag) {
updateLocal();
strcpy(asciiRep,asctime(&local));
aflag++;
}
}
public:
Time() { mark(); }
void mark() {
lflag = aflag = 0;
time(&t);
}
const char* ascii() {
updateAscii();
return asciiRep;
}
// Difference in seconds:
int delta(Time* dt) const {
return int(difftime(t, dt->t));
}
int daylightSavings() {
updateLocal();
return local.tm_isdst;
}
int dayOfYear() { // Since January 1
updateLocal();
return local.tm_yday;
}
int dayOfWeek() { // Since Sunday
updateLocal();
return local.tm_wday;
}
int since1900() { // Years since 1900
updateLocal();
return local.tm_year;
}
int month() { // Since January
updateLocal();
return local.tm_mon;
}
int dayOfMonth() {
updateLocal();
return local.tm_mday;
}
int hour() { // Since midnight, 24-hour clock
updateLocal();
return local.tm_hour;
}
int minute() {
updateLocal();
return local.tm_min;
}
int second() {
updateLocal();
return local.tm_sec;
}
};
#endif // CPPTIME_H ///:~
使用示例：
//: C09:Cpptime.cpp
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 2000
// Copyright notice in Copyright.txt
// Testing a simple time class
#include "head.h"
#include <iostream>
using namespace std;
int main() {
Time start;
for(int i = 1; i < 1000; i++) {
cout << i << ' ';
if(i%10 == 0) cout << endl;
}
Time end;
cout << endl;
cout << "start = " << start.ascii();
cout << "end = " << end.ascii();
cout << "delta = " << end.delta(&start);
} ///:~
摘自 yucan1001