Question

我一直在使用Visual Studio Express 13中的程序收到编译器错误我在代码中注释了编译器错误出现的两行

Date.cpp

#include "Date.h"
using namespace std;

Date::Date(int d, int m, int y) : day(d), month(m), year(y)
{}

Date::Date() : day(0), month(0), year(0)
{}

const int Date::getDay() { return day; }

const int Date::getMonth() { return month; }

const int Date::getYear(){ return year; }

bool Date::operator<(const Date dOther)
{
    return (year < dOther.year) || (year == dOther.year && month < dOther.month)
        || (year == dOther.year && month == dOther.month && day < dOther.day);
}

string Date::toString()   //Error: Declaration is incompatible with...declared at line 21...Date.h
{
    string s = month + "-" + day; s+="-" + year;
    return s;
}


ofstream& operator<<(ofstream& out, Date& d) 
{
    string s = d.toString();
    out.write(s.c_str(), s.size());         
    return out;
}

void Date::operator=(string s) //no instance of overloaded function "Date::operator=" matches the specified type
{
    stringstream stream;
    stream << s;
    stream >> month;
    stream >> day;
    stream >> year;
}

Date.h

#ifndef DATE_CLASS
#define DATE_CLASS
#include <iostream>
#include <string>
#include <fstream>
#include <sstream>

class Date
{
private:
int day, month, year;

public:
Date();
Date(int, int, int);

const int getDay();
const int getMonth();
const int getYear();

string toString();        
bool operator<(const Date);

friend ofstream& operator<<(ofstream& out, Date&d);


void operator=(string);

}; 

#endif

我不知道为什么会出现这些错误。这是运算符重载的问题吗？或者使用visual studio的东西（出于某种原因，如果我在Date.cpp中删除了一些代码，编译器错误会消失）？

Answer 1

您的命名空间不匹配。在标题中，您不在std之前使用string命名空间前缀，因此编译器无法找到您需要的类型string。

运算符重载错误？

1 个答案: