无法从Go到C ++序列化big.Int

Question

I've got the following Golang function:

//export getBigInt
func getBigInt() unsafe.Pointer {
    return C.CBytes(big.NewInt(int64(7)).Bytes())
}

Which I'm trying to call from C:

    uint8_t *byte_array = (uint8_t *)getBigInt();

    for (int i = 0; i < sizeof(byte_array); ++i) {
        std::cout << (int)byte_array[i] << std::endl;
    }

However instead outputting 0..., 7 I'm getting:

7
0
0
0
0
0
0
32

Answer 1

sizeof(byte_array) gives you the size of a pointer (in you case 8) and not the length of the array. The array is probably shorter than 8 elements causing your program to have undefined behavior.