IPV4掩码后地址计算

计算掩码后IP地址

template<class T>
class SingleInstance {
public:
    static inline T instance() {
        static T obj;
        return obj;
    }
private:
    SingleInstance() = default;
    ~SingleInstance() = default;
};
#include <stdint.h>
#include "single_instance.hpp"
class net_utility {
public:
    inline uint64_t get_mask(uint64_t ip, int mask) {
        if (ip > 0xFFFFFFFF) {
            return 0;
        }
        if (mask <= 0 || mask > 32) {
            return 0;
        }
        return ip & ((0xFFFFFFFF << (32 - mask)));
    }
};

#define G_NET_UTILITY SingleInstance<net_utility>::instance()
#include <iostream>
#include "net_utility.hpp"
int main(int argc, const char** argv) {
    uint64_t ip = 168432899;
    int mask = 24;
    uint64_t rs = G_NET_UTILITY.get_mask(ip, mask);
    std::cout << rs << std::endl;

    return 0;
}