Optimizing of explicit temporary storage

[Richard Guenther]

Is it legal for a conforming C++ compiler to optimize away storage 
allocation / deallocation?  Like in

#include <new>

void foo(void)
{
         int *x = new(std::nothrow) int;
         delete x;
}

is it allowed to kill the new and delete statements?  Would it be 
allowed to do this for the throwing version of new, too?

Thanks,
Richard.