如何在数组（动态数组）的开头打开一个空间？

function: shiftLeft() 
description: shifts all values in the array one space to the left in place (do not allocate a new array)
pre-condition: a MyVector object exists
post-condition: all values are shifted to the left (removes first value from the array)
return: nothing

我正在为动态数组T执行此功能

template <class T>
class MyVector :
{
private:
    T    *data;
    int  size;
    int  capacity;
    void grow();
    void shiftRight();
    void shiftLeft();
public:
    MyVector();
}

template <class T>
MyVector<T>:MyVector(){
    size = 0;
    capacity = 10;
    data = new T[capacity];
}

//my function of shiftLeft
//requirement: do not allocate a new array
template <class T>
void MyVector<T>::shiftLeft(){
    for(int i = 0; i < size-1; i++){
        data[i] = data[i+1];
    }
}

我不确定如何清除shiftLeft之后的最后一个元素。

另外，对于函数shiftRight

function: shiftRight()
description: shifts all values in the array one space to the right in place (do not allocate a new array)
pre-condition:a MyVector object exists
post-condition: all values are shifted to the right (opens up one space at the beginning of the array)
return: nothing

我不知道如何在数组的开头打开一个空间