是否可以通过带有运算符重载的索引来分配用户定义的数组？-C ++

“表达式不可分配。”

该错误是由iadrv.cpp中的以下代码行产生的：

IntArray a(10);
for(int i = a.low(); i <= a.high(); i++)
    a[i] = i * 10;

我可以像这样将整个IntArray对象分配给另一个对象a = b;，但是当引用特定的索引时，将发生“表达式不可分配”错误。

编辑：我const从大多数函数中删除了声明，并且我不再收到“表达式不可分配”错误了。但是，setName现在给出错误：

“ ISO C ++ 11不允许从字符串文字转换为'char *'”

此错误是由iadrv.cpp中的以下代码引起的：

a.setName("a");

我写了一个IntArray类（用C ++语言编写），其中以下运算符被重载：

• “ []”：允许索引范围检查
• “ =”：允许数组分配
• “ +”：允许将两个数组的总和分配给第三个数组
• “ + =”：允许将两个数组的总和分配给第一个数组
• “ <<”：允许输出数组的内容

该程序还包括以下功能：

• setName：设置IntArray对象的名称
• getName：返回IntArray对象的名称
• 低：返回最小的合法索引
• 高：返回最大的合法指数
• length：返回元素数

驱动程序（iadrv.cpp，iadrv.h）将在IntArray类（IntArray.cpp，IntArray.h）上运行测试，以确定是否所有操作符均已正确重载。

注意：对于每个数组测试数据，驱动程序将在每个数组初始化或修改后立即将数组索引乘以10并输出其内容。当程序遇到运行时错误时，应使用适当的诊断程序“模拟”停止，而不是实际停止程序。

IntArray.h

//  IntArray.h

#ifndef __IntArray__IntArray__
#define __IntArray__IntArray__

#include <iostream>
#include <fstream>
#include <iomanip>

using namespace std;

class IntArray {
private:
    int a, b;
    int size;
    int * num;
    char * name;
public:
    IntArray(int start, int finish);
    IntArray(int finish = 10);
    IntArray(const IntArray &); //constructor copy
    ~IntArray();
    int low() const;
    int high() const;
    char * getName() const;
    //removed the const declaration from functions below
    int & operator [] (int);     //made to return int&
    friend ostream & operator << (ostream &, IntArray &);
    void setName(char *);
    int length() const;
    const IntArray & operator = (IntArray &);
    const IntArray & operator + (IntArray &);
    bool operator += (IntArray &);

};

#endif /* defined(__IntArray__IntArray__) */

IntArray.cpp

//  IntArray.cpp

#include "IntArray.h"

#include <iostream>
#include <fstream>

using namespace std;

extern ofstream csis;

IntArray::IntArray(int start, int finish) {
    if (start > finish) {
        cout << "Simulating a halt.";
        a = finish;
        b = start;
    }
    else {
        a = start;
        b = finish;
    }
    size = b-a;
    num = new int[size];
    name = new char[1];
    for (int i = 0; i < size; i++) {
        num[i] = 0;
    }
}
IntArray::IntArray(int finish) {
    size = finish;
    a = 0;
    b = finish - 1;
    num = new int[size];
    name = new char[1];
    for (int i = 0; i < size; i++) {
        num[i] = 0;
    }
}
IntArray::IntArray (const IntArray & right): size(right.size) {
    num = new int[size];
    name = new char[1];
    for (int i = 0; i < size; i++) {
        num[i] = right.num[i];
    }
}
IntArray::~IntArray() {
    delete[] num;
    delete [] name;
}
int IntArray::low() const{
    return a;
}
int IntArray::high() const{
    return b;
}
char * IntArray::getName() const{
    return name;
}
void IntArray::setName(char * n) {
    name = n;
}
//removed const declarations
//made to return int&
int & IntArray::operator [] (int subscript) const{
    if (subscript < a || subscript > b) {
        cout << "subscript: " << subscript << endl;
        cout << "Out of bound error. Simulating a halt." << endl;
        return num[a];
    }
    return num[subscript-a];
}
int IntArray::length() const{
    //b-a = size
    return (b-a);
}
//removed const declarations
ostream & operator << (ostream & output, IntArray & array) {
    for (int i = array.low(); i <= array.high(); i++) {
        output << array.name << "[" << i << "] = " << array[i] << endl;
    }
    return output;
}
//removed const declarations
IntArray & IntArray::operator = (IntArray & right) {
    if (length() == right.length()) {
        for (int i = 0; i <= length(); i++) {
            num[i] = right[right.low()+i];
        }
    return * this;
    }
    else {
        delete [] num;  //reclaim space
        delete [] name;
        size = right.length();
        num = new int [size]; //space created
        cout << "Different sized arrays. Simulating a hault" << endl;
    }
    return * this;
}
//removed const declarations
IntArray & IntArray::operator + (IntArray & right) {
    int * ptr;
    ptr = new int [right.length()];
    if (length() == right.length()) {
        for (int i = 0; i < length(); i++) {
            ptr[i] = num[i] + right[right.low()+i];
        }
    }
    return * this;
}
//removed const declarations
bool IntArray::operator += (IntArray & right) {
    if (length() == right.length()) {
        for (int i = 0; i <= right.length(); i++) {
            num[i] += right[right.low()+i];
        }
        return true;
    }
    cout << "Could not add the sum of the arrays into first array. Simulating a halt." << endl;
    return false;
}

iadrv.h

//  iadrv.h

#ifndef p6_iadrv_h
#define p6_iadrv_h

#include "intarray.h"

int main();
void test1();
void wait();

#endif

iadrv.cpp

//  iadrv.cpp

#include <iostream>
#include <iomanip>
#include <fstream>
#include <stdlib.h>
#include "iadrv.h"

using namespace std;

ofstream csis;

int main() {
    csis.open("csis.dat");
    test1();
    csis.close();
}

void test1() {
    system("clear");
    cout << "1. Array declared with single integer: IntArray a(10);" << endl << endl;
    csis << "1. Array declared with single integer: IntArray a(10);" << endl << endl;
    IntArray a(10);
    for(int i = a.low(); i <= a.high(); i++)
        a[i] = i * 10;
    a.setName("a");
    cout << a << endl;
    csis << a << endl;
    wait();
}

免责声明：该程序是作为学校作业编写的，已经被上交评分。这是我的第一个C ++程序，所以我想了解我的错误。真诚的感谢您的帮助。