std::unordered_set<Key,Hash,KeyEqual,Allocator>::end, std::unordered_set<Key,Hash,KeyEqual,Allocator>::cend

#include <iostream>
#include <unordered_set>

struct Point { double x, y; };

int main()
{
    Point pts[3] = {{1, 0}, {2, 0}, {3, 0}};
    
    // points 是含有点的地址的 set
    std::unordered_set<Point *> points = { pts, pts + 1, pts + 2 };
    
    // 更改每个 (i, 0) 的 y 坐标从 0 到 i^2 并打印点
    for (auto iter = points.begin(); iter != points.end(); ++iter)
    {
        (*iter)->y = ((*iter)->x) * ((*iter)->x); // iter is a pointer-to-Point*
        std::cout << "(" << (*iter)->x << ", " << (*iter)->y << ") ";
    }
    std::cout << '\n';
    
    // 现在用基于范围的 for 循环，我们把每个 y 坐标增加 10
    for (Point* i : points)
    {
        i->y += 10;
        std::cout << "(" << i->x << ", " << i->y << ") ";
    }
}