gistfile1.txt

//
//  main.cpp
//  fdouble
//
//  Created by wshuai on 2021/12/29.
//

#include <stdio.h>

void * store[3];

void convert(float a, double b)
{
    store[0] = *(void**)&a;
    store[1] = *(void**)&b;
}

int main(int argc, const char * argv[]) {
    // insert code here...
    float arg1=29.88;
    double arg2=29.88;
    float arg3;
    
    store[0]=0;
    store[1]=0;
    convert(arg1, arg2);
    
    printf("%p\n", store[0]);
    printf("%p\n", store[1]);
    
    printf("%f\n", *(float *)(store+0));
    printf("%f\n", *(float *)(store+1));
    printf("%f\n", *(double *)(store+1));
    arg3 = *(double *)(store+1);
    printf("%f\n", arg3);
    
    store[2] = *(void**)&arg3;
    printf("%p\n", store[2]);
    printf("%f\n", *(float *)(store+2));
    printf("%f\n", *(double *)(store+2));
    return 0;
}
//MACOS X-code
/*
0xefbff47041ef0a3d
0x403de147ae147ae1
29.879999
-0.000000
29.880000
29.879999
0xae147ae141ef0a3d
29.879999
-0.000000
*/
//MSVC2017 x64
/*
0000000141EF0A3D
403DE147AE147AE1
29.879999
-0.000000
29.880000
29.879999
CCCCCCCC41EF0A3D
29.879999
-92559604747829222126337803568271202203659446267699534005010432.000000
*/