c++ - 自定义字符串类中的堆损坏

因此，当我使用智能指针创建我自己的字符串类时（这样我就可以习惯它们了），除operator +（）函数外，它一直运行良好。

它不断使程序崩溃，并且当VS调试程序时，析构函数将引发异常。我似乎无法查明原因，即使删除所有算法并仅返回mystring对象，这也是导致程序崩溃的唯一函数。

有什么建议么？

#include <iostream>
#include <string>
#include <memory>
#include <cstring>

using namespace std;

class mystring {
public:
    mystring() : word(make_unique<char[]>('\0')), len(0) {}
    ~mystring() { cout << "goodbye objects!";}
    mystring(const char *message) : word(make_unique<char[]>(strlen(message) + 1)), len(strlen(message)) {
        for (int i = 0; i < len; i++) word[i] = message[i];
        word[len] = '\0';
    }
    mystring(const mystring &rhs) : word(make_unique<char[]>(rhs.len)), len(rhs.len + 1) {
        for (int i = 0; i < len; i++) word[i] = rhs.word[i];
        word[len] = '\0';
    }
    mystring &operator=(const mystring &rhs) {
        if (this != &rhs) {
            releaseWord();
            word = make_unique<char[]>(rhs.len + 1);
            len = rhs.len;
            for (int i = 0; i < len; i++) word[i] = rhs.word[i];
            word[len] = '\0';
        }
        return *this;
    }

    //what is wrong with this function/what should be changed?
    friend mystring operator+(const mystring& lhs, const mystring& rhs) {
        mystring Result;

        int lhsLength = lhs.len, rhsLength = rhs.len;

        Result.releaseWord();
        Result.word = make_unique<char[]>(lhsLength + rhsLength + 1);
        Result.len = lhsLength + rhsLength;
        for (int i = 0; i < lhsLength; i++) Result.word[i] = lhs.word[i];
        for (int j = lhsLength; j < Result.len; j++) Result.word[j] = rhs.word[j];
        Result.word[Result.len] = '\0';


        return Result;
    }

    friend ostream &operator<<(ostream &os, const mystring &message) {
        return os << message.word.get();
    }
    int size() const {
        return len;
    }
private:
    int len;
    unique_ptr<char[]> word;
    void releaseWord() {
        char *temp = word.release();
        delete[] temp;
    }
};

int main()
{
    mystring word1 = "Darien", word2 = "Miller", word3;

    cout << word1 + word2;//causes heap corruption
    word3 = word1 + word2; //causes heap corruption

    return 0;
}

最佳答案

此行中的问题：

for (int j = lhsLength; j < Result.len; j++) Result.word[j] = rhs.word[j];

j对于rhs.word[j];是错误的

应该是rhs.word[j-lhsLength];之类的

您正在破坏阵列限制

关于c++ - 自定义字符串类中的堆损坏，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/48739717/