I think this is the closest you can get to a simple swap, but it does not have a straightforward usage pattern:
int swap(int a, int b) { // usage: y = swap(x, x=y);
return a;
}
y = swap(x, x=y);
It relies on the fact that x will pass into swap before y is assigned to x, then x is returned and assigned to y.
You can make it generic and swap any number of objects of the same type:
<T> T swap(T... args) { // usage: z = swap(a, a=b, b=c, ... y=z);
return args[0];
}
c = swap(a, a=b, b=c)