迭代器和指针有什么关系?

2021-12-13 00:00:00 pointers iterator c++ stl

带有迭代器的代码看起来很像带有指针的代码.迭代器属于某种晦涩的类型(例如 std::vector::iterator).

我不明白的是迭代器和指针是如何相互关联的――迭代器是一个指针的包装器,带有重载操作以前进到相邻元素还是其他东西?

解决方案

迭代器是指针的泛化.

迭代器(取决于变体)必须实现 * 和 ++

所以指针是迭代器.但不一定反过来.

如果你想迭代一个复杂的结构(一棵树、一个图......),迭代器将不仅仅是一个指针,并且不会对内存中的某个实际位置进行任何引用.

Code with iterators looks pretty much like code with pointers. Iterators are of some obscure type (like std::vector<int>::iterator for example).

What I don't get is how iterators and pointer are related to each other - is an iterator a wrapper around a pointer with overloaded operations to advance to adjacent elements or is it something else?

解决方案

Iterators are a generalization of pointers.

An iterator (depending on the variants) have to implement * and ++

So a pointer IS an iterator. But not necessarily the other way round.

If you want to iterate over a complex structure (a tree, a graph...), the iterator will be much more than a pointer, and doesn't make any reference to some actual place in the ram.

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