在构造函数中使用成员函数 [英] use of member functions in constructors
问题描述
这是我的队列类。是否可以从构造函数中调用私有成员函数
？
//自定义构造函数
MyQueue： ：MyQueue（unsigned long lInitialSize，
unsigned long lInitialSizeAlignment）
{
this-> pbQueue = NULL;
this-> InitializeClass（lInitialSize，lInitialSizeAlignment）;
}
//默认构造函数
MyQueue :: MyQueue（）
{
this-> pbQueue = NULL;
this-> InitializeClass（DEFAULT_SIZE，DEFAULT_SIZE_ALIGNMENT）;
} $ / $
//处理构造任务
void
MyQueue :: InitializeClass（unsigned long lInitialSize，
unsigned long lInitialSizeAlignment）
{
if（pbQueue！= NULL）
{
return;
}
if（lInitialSize == 0）
{
lInitialSize = DEFAULT_SIZE;
}
if（lInitialSizeAlignment = 0）
{
lInitialSizeAlignment = DEFAULT_SIZE_ALIGNMENT;
}
this-> pbQueue =（LPBYTE）HeapAlloc（hProcessHeap，HEAP_ZERO_MEMORY，
lInitialSize） ;
CheckAllocation（this-> pbQueue，1）;
this-> pbFront = this-> pbQueue;
this-> lQueueLength = 0;
this-> lQueueMax = lInitialSize;
this-> lSizeAlignment = lInitialSizeAlignment;
}
Here is my queue class. Is it okay to call a private member function
of the class from the constructor?
// custom constructor
MyQueue::MyQueue(unsigned long lInitialSize,
unsigned long lInitialSizeAlignment)
{
this->pbQueue = NULL;
this->InitializeClass(lInitialSize, lInitialSizeAlignment);
}
// default constructor
MyQueue::MyQueue()
{
this->pbQueue = NULL;
this->InitializeClass(DEFAULT_SIZE, DEFAULT_SIZE_ALIGNMENT);
}
// handles construction task
void
MyQueue::InitializeClass(unsigned long lInitialSize,
unsigned long lInitialSizeAlignment)
{
if(pbQueue != NULL)
{
return;
}
if(lInitialSize == 0)
{
lInitialSize = DEFAULT_SIZE;
}
if(lInitialSizeAlignment = 0)
{
lInitialSizeAlignment = DEFAULT_SIZE_ALIGNMENT;
}
this->pbQueue = (LPBYTE) HeapAlloc(hProcessHeap, HEAP_ZERO_MEMORY,
lInitialSize);
CheckAllocation(this->pbQueue, 1);
this->pbFront = this->pbQueue;
this->lQueueLength = 0;
this->lQueueMax = lInitialSize;
this->lSizeAlignment = lInitialSizeAlignment;
}
推荐答案
是否可以从构造函数中调用类的私有成员函数？
Is it okay to call a private member function
of the class from the constructor?
是的。您可以从以下位置调用类的私有成员函数：
A）在类的成员函数内（不一定是当前的
对象）。这包括来自任何构造函数和析构函数。
B）朋友函数和朋友类的成员函数。
-JKop
" Shailesh Humbad" <无***** @ nowhere.com>在消息中写道
"Shailesh Humbad" <no*****@nowhere.com> wrote in message
这是我的队列类。是否可以从构造函数中调用类的私有成员函数？
Here is my queue class. Is it okay to call a private member function
of the class from the constructor?
是的。实际上，这是一种在重载的
构造函数之间共享通用功能的方法。另请注意，构造函数内部未实现虚拟化。
Sharad
Yes. In fact this is a way to share common functionality between overloaded
constructors. Also note that virtuality is not achieved inside constructors.
Sharad
Sharad Kala写道：
Sharad Kala wrote:
Shailesh Humbad <无***** @ nowhere.com>在消息中写道
"Shailesh Humbad" <no*****@nowhere.com> wrote in message
这是我的队列类。可以从构造函数中调用类的私有成员函数吗？
Here is my queue class. Is it okay to call a private member function
of the class from the constructor?
是的。实际上，这是一种在重载的构造函数之间共享通用功能的方法。另请注意，构造函数内部未实现虚拟化。
Sharad
Yes. In fact this is a way to share common functionality between overloaded
constructors. Also note that virtuality is not achieved inside constructors.
Sharad
我发现了一个错误，因为我做了以下操作在我的构造函数中
MyObject :: MyObject（）{
//可能会导致错误，即风格不佳
ZeroMemory（这个，sizeof（this））;
...
}
工作正常，直到我添加了STL列表到MyObject。然后我在一个不相关的部分
代码中的begin（）函数调用中得到了访问冲突
。最后，我追踪它并意识到STL列表的所有内部指标都被重置为零（内存泄漏）。这个
的bug让我有点害怕从构造函数中访问正在构造的对象
，这就是我问这个问题的原因。所以我的
问题也是关于好的风格。
I just found a bug because I had done the following in my constructor
MyObject::MyObject() {
// may cause bugs later, i.e. poor style
ZeroMemory(this, sizeof(this));
...
}
It was working fine until I added an STL list to MyObject. Then I got
an access violation in a begin() function call in an unrelated piece
of code. Eventually, I tracked it down and realized all the internal
pointers of the STL list were being reset to zero (memory leak). This
bug just scared me a little to access the object being constructed
from within the constructor, which is why I asked the question. So my
question is about good style as well.
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