在C++中实现图形时，将map键定义为自定义结构

struct Key {
    int width;
    int height;
    std::string color;
};

bool operator<(const Key& lhs, const Key& rhs) {
    if (lhs.width != rhs.width) {
        return lhs.width < rhs.width;
    }
    if (lhs.height != rhs.height) {
        return lhs.height < rhs.height;
    }
    return lhs.color < rhs.color;
}

std::map<Key, Shape> shapeMap;
shapeMap.insert(std::make_pair(Key{10, 20, "red"}, Shape("Rectangle")));
shapeMap.insert(std::make_pair(Key{5, 5, "blue"}, Shape("Circle")));

auto it = shapeMap.find(Key{10, 20, "red"});
if (it != shapeMap.end()) {
    Shape& shape = it->second;
    // 对找到的图形进行操作
    shape.draw();
}