c++有迭代器但没有容器的类
我正在尝试实现一个类，该类允许我迭代 STL 样式的对象，而无需将它们显式存储在容器中。
一个简化的例子是，类中的
另外，我将其称为
我想我的问题是这样的：当没有容器时，用迭代器来思考是否合适？
谢谢
I'm trying to implement a class that would allow me to iterate over objects STL-style without explicitly storing them in a container.
A simplified example of this would be, say, a <Paragraph>::iterator in a class that doesn't actually have a container of Paragraphs, but instead has a <string> text variable. It's easy to create a member function that actually goes through text line by line and assemble paragraphs but it seems silly to me to store all this text again in some container just so that I could inherit from it's iterators.
Also, the reason I called it a <Paragraph>::iterator as opposed to a <string>::iterator is because I may want to have an iterator of some different type. For example, I could count the number of chars in each of the paragraphs and have an <int>::iterator.
I guess my question is this: is it appropriate to think in terms of iterators when there's no container?
Thanks
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这不仅是合适的，而且是一种优越的思维方式：类应该具有精益接口 - 也就是说，它们应该只公开他们需要公开的内容，仅此而已。如何在内部处理段落（是否将它们存储在容器中，如果是，存储在哪个容器中）是实现细节，不属于类的接口。
在任何情况下，该类都应该只公开段落的迭代器范围。一旦您在接口级别上摆脱了容器，就可能没有理由在类中拥有一个容器，正如您自己所注意到的那样。
It’s not only appropriate, it’s the superior way of thinking: classes should have lean interfaces – that is, they should only expose what they need to expose, nothing more. How you handle paragraphs internally (whether you store them in a container, and if so, in which container) is an implementation detail and doesn’t belong in the class’ interface.
The class should in any case only expose an iterator range of the paragraphs. And once you’ve thus got rid of the container on the interface level there might not be a reason to have one inside the class, as you’ve noticed yourself.
是的，迭代器概念完全独立于容器的概念。
例如，标准库有一组流迭代器。任何可以迭代的东西都应该用 C++ 中的迭代器来表示，无论是否有底层的内存容器。
Yes, the iterator concept is completely independent of the concept of a container.
The standard library has a set of stream iterators, for example. Anything that can be iterated over should be represented by iterators in C++, whether or not there is an underlying in-memory container.
Boost.Range 就是围绕这个概念而设计的。
http://www.boost.org/doc/libs/release /libs/range/index.html
Boost.Range is geared around this concept.
http://www.boost.org/doc/libs/release/libs/range/index.html
在我看来，您正在将
Paragraph对象视为段落的容器。但是Paragraph不会是Paragraph容器的一部分吗？每个Paragraph都是单词容器（或字符串，具体取决于您的需要）？那么您可以在Paragraph对象中使用std::string迭代器，并使用 std 容器来保存Paragraph吗？您仍然可以创建一个自定义迭代器来迭代您想要的任何内容，无论您想要什么，这个问题的答案 很好地概述了如何构建迭代器类。
Sounds to me like you are treating a
Paragraphobject as a container of paragrahs. But wouldn't aParagraphbe part of a container ofParagraphs? and eachParagraphbe a container of words (or a string, depending on your needs)? so you could use thestd::stringiterator in theParagraphobject, and a std container to hold theParagraph?You can still create a custom iterator to iterate over what ever you want, however you want, the answer to this question gives a good overview of how to structure your iterator class.