C++-类型转换(static_cast, const_cast, reinterpret_cast)

/*
static_cast 类型转换 
*/ 
#include <iostream>

using namespace std; 

int main() {
    int* pi = NULL; 
    //char c = int(pi); //C++类型转换 
    //char c = (int)pi; //C类型转换 
    void* pc = pi; 
    pi = static_cast<int *>(pc); 
    char c = static_cast<int>(pi); //会出现报错，因为int* 无法转换为int类型  

}

/* 
const_cast
*/
#include <iostream>

using namespace std; 

int main() {
    //volatile表示易变的，可以变化的 
    const volatile int ci = 100; //表示数字是易变 
    int* pi = const_cast<int *>(&ci); //进行地址的赋值操作
    *pi = 200; //对地址进行赋值 
    cout << *pi << endl; 
    cout << ci << endl; 
    cout << (void *)&ci << endl; 
    cout << pi << endl; 
}

/*
进行隐式转换
*/ 
#include <iostream>

using namespace std; 

int main(void) {
    //\000 = "\0" --> 0 
    char buf[] = "0001\00012345678\000123456"; 
    struct Http {
        char type[5]; 
        char id[9]; 
        char passward[7]; 
    };
    Http *p_http = reinterpret_cast<Http*>(buf); 
    cout << p_http->type << endl; 
    cout << p_http->id << endl; 
    cout << p_http->passward << endl; 
    return 0; 
}