Custom operator new and operator delete
I am surprised this compiles and works (it does I test it)

 global_handler();


As global handler is a pointer to a function  I was expecting to see this:

 (*global_handler)();


Comments:

Throw specifiers (except no throw) have been deprecated in the latest standard.
So you should probably follow their lead in that

void* operator new(std::size_t n) throw(std::bad_alloc)


The array version of new calls the no-throw version of new.  

void* operator new[](size_t n, std::nothrow_t const&amp;) throw()


Thus you are not getting the benefits of any registered out of memory handlers. Maybe you should just call the normal version of new so that the out of memory handlers are called for arrays as-well.


  Do I need any special alignment handling?


No. malloc() provides memory that is aligned for any type.
http://pubs.opengroup.org/onlinepubs/009695399/functions/malloc.html


  Should there be any other differences between operator new and operator new[]?


No. Apart from not using the out of memory handlers it looks fine.