std::unordered_map<Foo，Bar>测试是否存在特定的Foo键

#include <iostream>
#include <unordered_map>

struct Foo {
    int id;
    std::string name;
};

struct Bar {
    std::string description;
};

int main() {
    std::unordered_map<Foo, Bar> myMap;

    Foo foo1{1, "Foo1"};
    Bar bar1{"Bar1"};
    myMap[foo1] = bar1;

    Foo foo2{2, "Foo2"};
    Bar bar2{"Bar2"};
    myMap[foo2] = bar2;

    Foo foo3{3, "Foo3"};
    Bar bar3{"Bar3"};
    myMap[foo3] = bar3;

    Foo fooToFind{2, "Foo2"};

    if (myMap.count(fooToFind) > 0) {
        std::cout << "Foo2键存在于std::unordered_map中" << std::endl;
    } else {
        std::cout << "Foo2键不存在于std::unordered_map中" << std::endl;
    }

    return 0;
}