blocks|key|447289|text|我只是偶然发现了你的问题，希望不会太晚。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|447290|我推荐一个很好的(开源)库，名为洛基。它有一个基于向量的关联容器实现，它是std::map的插入替代，称为AssocVector。|offset|length|447291|它为访问元素提供了更好的性能(插入/删除的性能最差)。|447292|这个库是由亚历山大斯库编写的，“现代C%2B%2B设计”的作者。|447293|它还包含了其他一些非常漂亮的东西。|447294|entityMap|0|LINK|mutability|MUTABLE|url|http://loki-lib.sourceforge.net/|1|https://github.com/snaewe/loki-lib/blob/master/include/loki/AssocVector.h|2|http://en.wikipedia.org/wiki/Andrei_Alexandrescu|3|http://en.wikipedia.org/wiki/Modern_C%252B%252B_Design^0|0|G|2|0|1H|B|1|0|0|5|6|2|G|7|3|0|0^^$0|@$1|2|3|4|5|6|7|Z|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|10|8|@]|9|@$D|11|E|12|1|13]|$D|14|E|15|1|16]]|A|$]]|$1|F|3|G|5|6|7|17|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|18|8|@]|9|@$D|19|E|1A|1|1B]|$D|1C|E|1D|1|1E]]|A|$]]|$1|J|3|K|5|6|7|1F|8|@]|9|@]|A|$]]|$1|L|3|-4|5|6|7|1G|8|@]|9|@]|A|$]]]|M|$N|$5|O|P|Q|A|$R|S]]|T|$5|O|P|Q|A|$R|U]]|V|$5|O|P|Q|A|$R|W]]|X|$5|O|P|Q|A|$R|Y]]]]

I just stumbled upon your question, hope its not too late.

I recommend a great (open source) library named <a href="http://loki-lib.sourceforge.net/" rel="nofollow noreferrer">Loki</a>.
It has a vector based implementation of an associative container that is a drop-in replacement for std::map, called <a href="https://github.com/snaewe/loki-lib/blob/master/include/loki/AssocVector.h" rel="nofollow noreferrer">AssocVector</a>.

It offers better performance for accessing elements (and worst performance for insertions/deletions).

The library was written by <a href="http://en.wikipedia.org/wiki/Andrei_Alexandrescu" rel="nofollow noreferrer">Andrei Alexandrescu</a> author of <a href="http://en.wikipedia.org/wiki/Modern_C%2B%2B_Design" rel="nofollow noreferrer">Modern C++ Design</a>.

It also contains some other really nifty stuff.

blocks|key|447198|text|如果找不到合适的东西，我只需包装std::vector+()来对insert执行排序()，然后使用lower_bound()实现find()。它应该是直截了当的，并且和自定义解决方案一样有效。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|447199|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

If you can't find anything suitable, I would just wrap a std::vector to do sort() on insert, and implement find() using lower_bound(). It should be straight forward, and just as efficient as a custom solution.

blocks|key|756907|text|我知道，以前的帖子，但对于最近的访问者来说，Boost的flat_set和flat_map看上去就像你所需要的。有关详细信息，请参阅https://theboostcpplibraries.com/boost.container。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|756908|entityMap|0|LINK|mutability|MUTABLE|url|https://theboostcpplibraries.com/boost.container^0|1U|1C|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

Old post, I know, but for more recent visitors, Boost's flat_set and flat_map look like what you need. See <a href="https://theboostcpplibraries.com/boost.container" rel="nofollow noreferrer">https://theboostcpplibraries.com/boost.container</a> for more information.

blocks|key|1980826|text|我不知道任何这样的实现，但是有一些函数可以帮助处理STL中已经排序过的向量，比如lower_bound和upper_bound。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1980827|entityMap|0|LINK|mutability|MUTABLE|url|http://www.sgi.com/tech/stl/lower_bound.html|1|http://www.sgi.com/tech/stl/upper_bound.html^0|14|B|1G|B|14|B|0|1G|B|1|0^^$0|@$1|2|3|4|5|6|7|P|8|@$9|Q|A|R|B|C]|$9|S|A|T|B|C]]|D|@$9|U|A|V|1|W]|$9|X|A|Y|1|Z]]|E|$]]|$1|F|3|-4|5|6|7|10|8|@]|D|@]|E|$]]]|G|$H|$5|I|J|K|E|$L|M]]|N|$5|I|J|K|E|$L|O]]]]

I don't know any such implementation, but there are some functions that help working with sorted vectors already in STL, such as <a href="http://www.sgi.com/tech/stl/lower_bound.html" rel="nofollow noreferrer"><code>lower_bound</code></a> and <a href="http://www.sgi.com/tech/stl/upper_bound.html" rel="nofollow noreferrer"><code>upper_bound</code></a>.

blocks|key|447163|text|如果集合或地图确实很小，通过微观优化数据结构所获得的性能将几乎没有显著的效果。在搜索小树和小向量时，您可能会节省一两个内存(读:缓存)查找，这在大图中是微不足道的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|447164|话虽如此，您还是可以尝试一下hash_map。按键进行的查找保证在固定时间内运行。|447165|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

If the set or map truly is small, the performance gained by micro-optimizing the data structure will have little to no noticeable effects. You'll save maybe one or two memory (read: cache) lookups when searching a tiny tree vs tiny vector, which in the big picture is insignificant.

Having said that, you could give hash_map a try. Lookups by key are guaranteed to run in constant time.

blocks|key|1980849|text|也许您正在寻找无序映射和无序集。尝试查看依赖散列的TR1无序容器，或者Boost.Unordered容器库。在接口下面，我不确定他们是否真的使用了std::vector，但我敢打赌这是值得一看的。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1980850|entityMap|0|LINK|mutability|MUTABLE|url|http://www.boost.org/doc/libs/1_37_0/doc/html/unordered.html^0|Z|F|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

Maybe you're looking for unordered map's and unordered set's. Try taking a look at the TR1 unordered containers that rely on hashing, or the <a href="http://www.boost.org/doc/libs/1_37_0/doc/html/unordered.html" rel="nofollow noreferrer">Boost.Unordered</a> container library. Underneath the interface, I'm not sure if they really do use std::vector, but I'd wager it's worth taking a look at.

For small sets or maps, it's usually much faster to just use a sorted vector, instead of the tree-based <code>set</code>/<code>map</code> - especially for something like 5-10 elements. LLVM has some classes <a href="http://llvm.org/docs/ProgrammersManual.html#ds_sequential" rel="noreferrer">in that spirit</a>, but no real adapter that would provide a <code>std::map</code> like interface backed up with a <code>std::vector</code>.

Any (free) implementation of this out there?

Edit: Thanks for all the alternative ideas, but I'm really interested in a vector based set/map. I do have specific cases where I tend to create huge amounts of sets/maps which contain usually less than 10 elements, and I do really want to have less memory pressure. Think about for example neighbor edges for a vertex in a triangle mesh, you easily wind up with 100k sets of 3-4 elements each.

Is there already some std::vector based set/map implementation?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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对于小集合或地图，使用排序向量通常要快得多，而不是基于树的set/map --特别是对于5-10个元素。LLVM有一些类，但没有真正的适配器提供像std::map那样的带有std::vector备份的接口。有(免费)实现这一点吗？编辑：谢谢你提供的所有其他想法，但我真的对基于向量的集/映射感兴趣。我确实有一些特殊的例子，我倾向于创建大量的集合/地图，这些集合/地图通常包含的元素少于10个，而且我确

问是否已经有了一些基于向量的集/地图实现？
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