是thare在STL或增大图像查找并弹出操作容器？ [英] Is thare in STL or BOOST map like container with find and pop operation?

问题描述

我希望我的地图，可搜索，我想能够从该像被时间最长的前插入它（与它的API元素踢出 map.remove（map.get_iterator_to_oldest_inserted_element（）） ），如queqe和地图的搭配..是否有STL中的任何此类容器或提升？

I want my map to be searchable and I want to be capable to kick out from it elements that were inserted into it longest time ago (with api like map.remove(map.get_iterator_to_oldest_inserted_element()) ) like mix of queqe and map.. Is there any such container in STL or Boost?

推荐答案

您可以使用的的boost :: multi_index 使用 ordered_unique 和序指标，如这个例子。

You can use boost::multi_index using the ordered_unique and sequence indices, as in this example.

#include <iostream>
#include <boost/multi_index_container.hpp>
#include <boost/multi_index/ordered_index.hpp>
#include <boost/multi_index/sequenced_index.hpp>
#include <boost/multi_index/member.hpp>

// Element type to store in container
struct Element
{
    std::string key;
    int value;

    Element(const std::string& key, int value) : key(key), value(value) {}
};

namespace bmi = boost::multi_index;

// Boost multi_index container
typedef bmi::multi_index_container<
    Element,
    bmi::indexed_by<
        bmi::ordered_unique< bmi::member<Element,std::string,&Element::key> >,
        bmi::sequenced<> >
    >
    MyContainer;

typedef MyContainer::nth_index<1>::type BySequence;

// Helper function that returns a sequence view of the container.
BySequence& bySequence(MyContainer& container) {return container.get<1>();}

int main()
{
    MyContainer container;

    // Access container by sequence. Push back elements.
    BySequence& sequence = bySequence(container);
    sequence.push_back(Element("one", 1));
    sequence.push_back(Element("two", 2));
    sequence.push_back(Element("three", 3));

    // Access container by key. Find an element.
    // By default the container is accessed as nth_index<0>
    MyContainer::const_iterator it = container.find("two");
    if (it != container.end())
        std::cout << it->value << "\n";

    // Access container by sequence. Pop elements in a FIFO manner,
    while (!sequence.empty())
    {
        std::cout << sequence.front().value << "\n";
        sequence.pop_front();
    }
}

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