Renaming first and second of a map iterator

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北恋 2020-12-14 02:41

Is there any way to rename the first and second accessor functions of a map iterator. I understand they have these names because of the underlying pair which represents the

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粉色の甜心 (楼主)

2020-12-14 02:53

I wouldn't recommend really using this, but it does seem to work, at least to the minimum degree of the test program doing what I wanted/expected:

#include 
#include 
#include 

template 
struct my_pair : public std::pair {
    T const &vertex;
    my_pair(std::pair const &x) : std::pair(x), vertex(x.first) { }
};

template 
struct my_map : public std::map { 
    my_pair find(T const &t) { return my_pair(*std::map::find(t)); }
};

class Vertex { 
    int x;
public:
    Vertex(int v) : x(v) {}
    bool operator<(Vertex const &other) const { return x < other.x; }
    friend std::ostream &operator<<(std::ostream &os, Vertex const &v) { return os << v.x; }
};

int main() { 
    my_map m;

    m[1] = "This is it";

    my_pair mp = m.find(1);
    std::cout << mp.vertex << ": " << mp.second;
    return 0;
}

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