错误C2440:“正在初始化”:无法从“ CTable”转换为“ CTable”

时间:2019-11-04 13:41:37

标签: c++ operator-overloading

老实说,我不知道为什么CTable无法转换为CTable?我正在尝试使重载运算符+返回串联的两个表。

错误C2440'正在初始化':无法从'CTable'转换为'CTable'

第二个错误:错误(活动)E0334类“ CTable”没有合适的复制构造函数

#include <iostream>
#include <string>
#include "CTable.h"
int main() {
    CTable c_tab_1, c_tab_0;
    c_tab_0.vSetValueAt(0, 1);
    c_tab_0.vPrint();
    c_tab_0.bSetNewSize(4);
    c_tab_0.vPrint();
    c_tab_1.bSetNewSize(4);

    c_tab_0.vSetValueAt(0, 1);
    c_tab_0.vSetValueAt(1, 2);
    c_tab_0.vSetValueAt(2, 3);
    c_tab_0.vSetValueAt(3, 4);
    c_tab_0.vPrint();

    c_tab_1.vSetValueAt(0, 2);
    c_tab_1.vSetValueAt(1, 3);
    c_tab_1.vSetValueAt(2, 4);
    c_tab_1.vSetValueAt(3, 5);
    c_tab_1.vPrint();

    c_tab_1.vSetValueAt(2, 123);
    c_tab_0.vPrint();
    c_tab_1.vPrint();

    CTable c_tab_3 = c_tab_0 + c_tab_1; //Error C2440!  <-----------------------
    c_tab_3.vPrint();

    return 0;
}
#include <iostream>
#include <string>

using namespace std;

class CTable {

public:
    CTable();
    CTable(CTable& pcOther);
    CTable* pcClone();
    ~CTable();

    bool bSetNewSize(int iTableLen);
    void vSetValueAt(int iOffset, int iNewVal);
    void vPrint();
    CTable operator+(const CTable& pcNewTable);

private:

    string s_name;
    int i_size;
    int* piTable;

    const int SIZE = 10;
    const string NAME = "Name";
};
#include <iostream>
#include <string>
#include "CTable.h"

using namespace std;

CTable::CTable() {

    s_name = NAME;
    cout << "bezp: " << s_name << endl;
    piTable = new int[SIZE];
    i_size = SIZE;
}
///
CTable::CTable(CTable& pcOther) {

    s_name = pcOther.s_name + "_copy";
    piTable = new int[pcOther.i_size];
    i_size = pcOther.i_size;
    for (int i = 0; i < pcOther.i_size; i++) {
        piTable[i] = pcOther.piTable[i];
    }
    cout << "kopiuj: " << s_name << endl;
}

CTable::~CTable() {
    delete[] piTable;
    cout << "usuwam " << s_name << endl;
}
////
bool CTable::bSetNewSize(int iTableLen) {

    if (iTableLen <= 0) {
        return false;
    }

    int* pi_newTable = new int[iTableLen];
    memcpy(pi_newTable, piTable, iTableLen);
    delete this->piTable;
    this->i_size = iTableLen;
    this->piTable = pi_newTable;

    return true;
}
///
void CTable::vSetValueAt(int iOffset, int iNewVal) {
    if (iOffset >= this->i_size) {
        return;
    }
    piTable[iOffset] = iNewVal;
}

void CTable::vPrint() {
    for (int i = 0; i < i_size; i++) {
        cout << piTable[i] << " ";
    }
    cout << endl;
}

CTable CTable::operator+(const CTable& pcNewTable) {
    CTable result;

    int greater_len = i_size < pcNewTable.i_size;
    int smaller_len = i_size > pcNewTable.i_size;
    int* greater_table = i_size > pcNewTable.i_size ? piTable : pcNewTable.piTable;
    int* smaller_table = i_size <= pcNewTable.i_size ? piTable : pcNewTable.piTable;

    result.i_size = greater_len;
    result.piTable = new int[greater_len];

    memcpy(result.piTable, greater_table, greater_len * sizeof(int));

    for (int i = 0; i < smaller_len; i++) {
        result.piTable[i] += smaller_table[i];
    }

    return result;
}

我应该纠正什么?

1 个答案:

答案 0 :(得分:3)

尝试定义

    CTable(const CTable& pcOther)
    { 
     .......
    }