为我的对象分配特定/显式的内存位置 [英] Assigning specific/explicit memory locations to my objects

问题描述

我可以在C ++中使对象明确指定其内存地址吗?这是因为我为每个实体(对象)有单独的ID.因此，如果我能做到这一点，我将能够仅通过添加指针就可以遍历所有对象. 考虑: 我有一个内存位置为x的对象. 我想创建一个下一个对象，其内存位置为x +(下一个对象的唯一ID)* K 其中K是两个物体之间的恒定间隙(例如)

Can i make an object in C++ specifying its memory address explicitly? This is because i am having separate ids for each of my entities (the objects). So if i can do this, i will be able to traverse through all my objects by mere pointer additions. Consider: I have an object with memory location x. I want to create the next object with memory location x+(the unique id of the next object)*K where K is the constant gap between two objects(say)

推荐答案

您可以使用放置new运算符来指定内存.

You can specify the memory using the placement new operator.

因此，如果我能做到这一点，我将能够通过仅添加指针来遍历所有对象.

So if i can do this, i will be able to traverse through all my objects by mere pointer additions.

并非如此. 无视告诉您执行此操作的答案！您不能在数组外部进行指针算术运算.仅仅因为您有2个对象o1和o2，一个位于0x4，另一个位于0x5，并不意味着&o1 + 1将产生&o2.实际上，这是未定义的行为.

Not really. Disregard answers that tell you to do this! You can't do pointer arithmetics outside of an array. Just because you have 2 objects o1 and o2, one located at 0x4 and the other at 0x5, it doesn't mean that &o1 + 1 will yield &o2. In fact, it's undefined behavior.

要使此功能按预期工作，可以动态分配内存，或者更好的是使用std::vector并使用迭代器. (这就是他们的目的)

For this to work as expected, you can allocate the memory dynamically, or, better yet, use a std::vector and use iterators. (that's what they are for)

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