Given this code:

void FrMemCopy(void *to, const void *from, size_t sz)
{
    size_t sz8 = sz >> 3;
    size_t sz1 = sz - (sz8 << 3);

    while (sz8-- != 0) {
        *((double *)to)++ = *((double *)from)++;
    }

    while (sz1-- != 0) {
        *((char *)to)++ = *((char *)from)++;
    }
}

I am receiving target of assignment not really an lvalue warnings on the 2 lines inside the while loops.

Can anyone break down those lines?

a cast then an increment?

What is a simplier way to write that?

What does the error mean?