简单的用户定义向量模板示例

Question

考虑下面的代码：

template<typename T> 
class vecTor 
{ 
int size; 
T *v; 
    public: 
vecTor(int s=0): size(s), 
    v(new T[size]) // conv. ctor [1] 
    { 
     for(int i=0; i<size; i++) 
      v[i]=0; 
    } 

vecTor(T *x,int s) // [2] this conv. ctor produces seg. fault if called 
{ 
    size=s; 
    for(int i=0; i<size; i++) 
    v[i] = x[i]; 
} 

void vecTorset(T *a,int s) // this method works fine 
{       // instead of [2] 
    size=s; 
    for(int i=0; i<size; i++) 
     v[i] = a[i]; 
} 

~vecTor() 
{ 
    delete [] v; 
} 

void printvec() const; 
}; 

    template<typename T> 
    void vecTor<T>::printvec() const 
    { 
    cout<<"Vector is:\n"; 
     for(int i=0; i<size; i++) 
     cout<< v[i] <<" "; 
     cout<<"\n"; 
    } 

int main() 
{ 
    int a[3]= {3,5,7}; 

    vecTor<int> v1(3); 

    v1=vecTor<int>(a,3); // this call produces seg. fault 

    //v1.vecTorset(a,3); //this call works fine 

    v1.printvec(); 

    return 0; 

}

如果我称第二转换构造函数

 v1=vecTor<int>(a,3); 

我在codepad.org得到分割故障;它在mingw上崩溃。可能是什么问题呢？

Answer 1

您还没有初始化T*

vecTor(T *x,int s) : size(s), v(new T[size]) 
{ 
    for(int i=0; i<size; i++) 
    v[i] = x[i]; 
}