C++是否可以使用.获取union、struct中的成员变量的地址

C++可以使用.获取union、struct中的成员变量的地址

示例代码如下所示

#include <stdio.h>
#include <stdint.h>struct u128 { uint64_t v64; uint64_t v0; };int main() {union { unsigned __int128 ui; struct u128 s; } union_temp_m128;void* p1 = &union_temp_m128;void* p2 = &(union_temp_m128.ui);void* p3 = &(union_temp_m128.ui);void* p4 = &(union_temp_m128.s.v64);void* p5 = &(union_temp_m128.s.v0);printf("p1: %p\n", &union_temp_m128);printf("p2: %p\n", &(union_temp_m128.ui));printf("p3: %p\n", &(union_temp_m128.s));printf("p4: %p\n", &(union_temp_m128.s.v64));printf("p5: %p\n", &(union_temp_m128.s.v0));if(p1==p2) {printf("p1==p2\n");}else {printf("p1!=p2\n");}if(p1==p3) {printf("p1==p3\n");}else {printf("p1!=p3\n");}if(p1==p4) {printf("p1==p4\n");}else {printf("p1!=p4\n");}if(p1==p5) {printf("p1==p5\n");}else {printf("p1!=p5\n");}return 0;
}

运行结果如下所示

p1: 0x7ffeb8fe8380
p2: 0x7ffeb8fe8380
p3: 0x7ffeb8fe8380
p4: 0x7ffeb8fe8380
p5: 0x7ffeb8fe8388
p1==p2
p1==p3
p1==p4
p1!=p5