c++ - std::priority_queue 复杂类型？

Question

我想使用复杂类型的 std::priority_queue:

typedef struct
{
uint8_t data;
    uint64_t moredata;
}myData;

typedef struct
{
    boost::mutex someQueueLock;
    std::priority_queue<myData> myQueue; //does not work
}

我不想使用充满指针的队列 (priority_queue)，因为指针可能会变得无效。

这可能吗？或者我应该使用另一个 std 容器？

Answer 1

std::priority_queue使用 operator<默认情况下对元素进行排序，它要求元素是严格弱排序

你需要定义operator< myData 的功能类型

bool operator<(const myData& lhs, const myData& rhs)
{
    return lhs.data < rhs.data;
}

§ 23.6.4.1 类模板priority_queue

Any sequence container with random access iterator and supporting operations front(), push_back() and pop_back() can be used to instantiate priority_queue. In particular, vector (23.3.6) and deque (23.3.3) can be used. Instantiating priority_queue also involves supplying a function or function object for mak- ing priority comparisons; the library assumes that the function or function object defines a strict weak ordering (25.4).

§ 25.4

All the operations in 25.4 have two versions: one that takes a function object of type Compare and one that uses an operator<.