原來 double 是指標啊

double.c

#include <stdio.h>

int main(int argc, const char *argv[]) {
    double d = 12.34;
    printf("d 0x%016x\n", d);
    printf("&d 0x%016x\n", &d);
    printf("*(long long *)&d 0x%016lx\n", *(long long *)&d);
    return 0;
}

// d 0x0000000056b164a0
// &d 0x0000000056b16460
// *(long long *)&d 0x4028ae147ae147ae