C ++中对象的静态和动态内存分配 [英] static and dynamic memory allocation of objects in C++
问题描述
在C ++程序中，对于一个类，我们如何获得静态创建并动态创建的任何时间点的活动对象的数量？
In a C++ program, for a class, how can we get the counts of the number of active objects at any point of time which are statically created and dynamically created separately??
推荐答案
很遗憾，你不能。
更多关于这个问题的更多信息有效的C ++ - 项目＃27：要求或禁止基于堆的对象。
More Effective C++ - Item #27: Requiring or prohibiting heap-based objects.
确定这里有一个很容易演示的问题我不会总结所有的，但这里至少有一个挑战）：
Ok here's one of the problems that is easily demonstrated (the item in question is several pages long so I won't summarize all of it but here's at least one challenge):
许多（但不是所有）系统以下列方式安排他们的内存：
Many (but not all) systems arrange their memory in the following fashion:
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| Stack |
| (Grows Down) |
| |
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| |
| |
| |
| |
| |
| |
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| Heap |
| (Grows Up) |
| |
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现在你可能会认为这样的内存安排，你可以做一些聪明的运算符new / new运算符，以确定你是否在堆上或不正确（通过检查，如果你在一个特定的内存位置以上或以下）。这里的问题。静态对象是系统依赖的，所以可能发生以下事情：
Now you might think with a memory arrangement like this you could do something clever with operator new/new operator to figure out if you're on the heap or not right (by checking if you're above or below a certain memory location)? Here's the problem. Where static objects go is system dependent, so the following thing could happen:
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| Stack |
| (Grows Down) |
| |
----------------
| |
| |
| |
| |
| |
| |
----------------
| Heap |
| (Grows Up) |
| |
----------------
| Static |
| Objects |
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您现在无法区分静态对象和堆对象。糟糕！也许你可能已经注意到我说这是系统依赖，这意味着即使你找出一种方法来区分它们，你的代码不会是可移植的。
You now fail to distinguish between static objects and heap object. Oops! Also you may have noticed I said this is system dependent, which means even if you were to figure out a way to distinguish between them, well your code would not be portable.
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