c++关键字delete出现未知信号

Question

#include <iostream>
template <class T>
class Vector{
public:
    typedef T value_type;
    typedef T * iterator;
    typedef size_t size_type;

private:
    value_type * data;
    size_type size;
    size_type totalSize;

public:
    //  default constructor(empty)
    Vector(void):data(nullptr),size(0),totalSize(0){};
    // deconstructor
    ~Vector(void){
        delete[] data;
        data = nullptr;
    }
    // expansion
    void expansion(size_type val){
        if (val <= totalSize){
            return;
        }
        value_type * temp = new value_type(val);
        for (size_type i = 0; i < size; ++i){
            temp[i] = data[i];
        }
        delete[] data;
        data = temp;
        totalSize = val;
    }
// modifiers
public:
    void push_back(value_type val);
};

template <class T>
void Vector<T>::push_back(value_type val){
    if (totalSize == 0){
        size = totalSize = 1;
        data = new value_type(totalSize);
    }
    else if (size + 1 > totalSize){
        this->expansion(totalSize * 2);
    }
    data[size] = val;
    size++;
}


int main(){
    Vector<int> vec;
    vec.push_back(10);
    vec.push_back(20); 
}

断点调试到该处时出现未知信号，一直找不到问题出在哪里。

Answer 1

push_back函数当totalSize=0时，不应将size设置成1。

#include <iostream>
#include <cassert>

using namespace std;

template <class T>
class Vector{
public:
    typedef T value_type;
    typedef T * iterator;
    typedef size_t size_type;
private:
    value_type * data;
    size_type size;
    size_type totalSize;
public:
    //  default constructor(empty)
    Vector(void):data(nullptr),size(0),totalSize(0){};
    // deconstructor
    ~Vector(void){
        delete[] data;
        data = nullptr;
    }
    // expansion
    void expansion(size_type val){
        if (val <= totalSize){
            return;
        }
        value_type * temp = new value_type(val);
        for (size_type i = 0; i < size; ++i){
            temp[i] = data[i];
        }
        delete[] data;
        data = temp;
        totalSize = val;
    }
// modifiers
public:
    void push_back(value_type val);
};
template <class T>
void Vector<T>::push_back(value_type val){
    if (totalSize == 0){
        /*size = */totalSize = 1;
        data = new value_type(totalSize);
    }
    else if (size + 1 > totalSize){
        this->expansion(totalSize * 2);
    }
    assert(size<totalSize);
    data[size] = val;
    cout<<data[size]<<",";
    size++;
}
int main(){
    Vector<int> vec;
    vec.push_back(10);
    vec.push_back(20);
    vec.push_back(30);
    vec.push_back(40);
    vec.push_back(50);
    return 0;
}