关于操作符重载的问题
本帖最后由 discory 于 2013-02-18 16:08:16 编辑
#include <iostream>
using std::cout;
using std::cin;
using std::endl;
using std::ostream;
using std::istream;
#include <iomanip>
using std::setw;
class PhoneNumber
{
friend ostream &operator <<( ostream&, const PhoneNumber & );
friend istream &operator >>( istream&, const PhoneNumber & );
private:
char areaCode[ 4 ];//3-digit area code and null
char exchange[ 4 ];//3-digit exchange and null
char line[ 5 ];//4-dighit line and null
};
//Overloaded stram-insertion operator( cannot be
//a member function if we would like to invoke it with
//cout << somePhoneNumber; )
ostream &operator <<( ostream &output, const PhoneNumber &num )
{
output << "(" << num.areaCode << ")"
<< num.exchange << "-" << num.line;
return output;//enables cout << a << b << c;
}
istream &operator >>( istream &input, const PhoneNumber &num )
{
input.ignore();//skip (
input >> setw( 4 ) >> num.areaCode;//这里报错
input.ignore( 2 );//skip )
input >> setw( 4 ) >> num.exchange;//这里报错
input.ignore();//skip dash (-)
input >> setw( 5 ) >> num.line;//这里报错
return input;//enables cin >> a >> b >> c;
}
int main()
{
PhoneNumber phone;//create object phone
cout << "Enter phone number in the form (123) 456-7890: \n";
//cin >> phone invokes operator >> function by
//issuing the call operator >>( cin, phone ).
cin >> phone;
//cout << phone invokes operator << function by
//issuing the call operator <<( cout, phone ).
cout << "The phone number entered was: " << phone << endl;
system("pause");
return 0;
}
const了怎么修改内容？
[解决办法]
friend istream &operator >>( istream&, const PhoneNumber & );
被const打败了
