Convert some ints into a byte array without allocations?

[Yazan D via Digitalmars-d-learn]

On Sat, 16 Jan 2016 14:42:27 +0000, Yazan D wrote:
> 
> You can do this:
> ubyte[] b = (cast(ubyte*) &a)[0 .. int.sizeof];
> 
> It is casting the pointer to `a` to a ubyte (or byte) pointer and then
> taking a slice the size of int.

You can also use a union:

union Foo
{
  int i;
  ubyte[4] b;
}

// write to int part
Foo f = Foo(a);
// then read from ubyte part
writeln(foo.b);

ps. I am not sure of the aliasing rules in D for unions. In C, this is 
allowed, but in C++, this is undefined behaviour AFAIK.