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c++ 操作符重载

2013年03月18日 ⁄ 综合 ⁄ 共 1845字 ⁄ 字号 评论关闭

c++
操作符重载

 

 

 /* file = main.cpp 涉及操作符重载,友元函数,重载类型转换*/
#include <iostream>
#include "testClass.h"
using namespace std;

int main()
{
    testClass tc1(2);
    testClass tc2(3);
    testClass tc3 = 1 + tc1 + tc2 + 4;// 重载加法
    testClass tc4 = 5 - tc2 - tc1 - 1;//
重载减法
    int a = tc1;//
重载了类型转换
    cout << "tc3:= " << tc3 <<
", tc4:=" << tc4 << endl;
    //
重载了类型转换才能用下面这样的语句
    cout << "tc3 + t4 := " << tc3 + tc4
<< endl;
    cout << "tc3 - t4 := " << tc3 - tc4
<< endl;
    return 0;
}
/* file = testClass.h */
#ifndef TESTCLASS_H
#define TESTCLASS_H
#include <iostream>
class testClass
{
    public:
        testClass(int i);
        virtual ~testClass();
        testClass operator +(testClass &
sf) const;
        testClass operator +(int j) const;
        testClass operator -(testClass &
sf) const;
        testClass operator -(int j) const;
        operator int() const;//
重载类型转换;必须是成员函数,零参数,无返回值
        friend testClass operator +(int j,
testClass & sf);
        friend testClass operator -(int j,
testClass & sf);
        friend std::ostream & operator
<<(std::ostream & os, testClass & sf);
    protected:
    private:
        int m_i;
};

#endif // TESTCLASS_H

/* file = testClass.cpp */
#include "testClass.h"

testClass::testClass(int i)
{
    this->m_i = i;
}

testClass::~testClass()
{
}

testClass testClass::operator +(testClass & sf) const{
testClass tc(this->m_i + sf.m_i);
return tc;
}

testClass testClass::operator +(int j) const{
testClass tc(this->m_i + j);
return tc;
}

testClass operator +(int j, testClass & sf){
   return sf + j;
}

testClass testClass::operator -(testClass & sf) const{
testClass tc(this->m_i - sf.m_i);
return tc;
}

testClass testClass::operator -(int j) const{
testClass tc(this->m_i - j);
return tc;
}

testClass operator -(int j, testClass & sf){
testClass tc(j - sf.m_i);
return tc;
}

testClass::operator int() const{
return this->m_i;
}

std::ostream & operator <<(std::ostream & os, testClass &
sf){
    os << sf.m_i;
    return os;
}
共含三个文件,在winxp + codeblock
8.02
上测试通过,由于codeblock 新创建的类文件头文件放在include路径下,需要在project ->
build options -> Search directories -> Compiler -> Add ,
添加一个include 路径,否则codeblock 会报告找不到头文件"testClass.h"

 

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