* allocate(s) returns a ubyte[] with length at least s, or null. (It does not throw on out-of-memory because that would hurt composability; it turns out many elemental allocators do naturally run out of memory.) This method is required for all allocators. In most allocators this method should be @safe.
Would an 'expected' be a possible alternative to returning null?
Am a big fan of this talk of yours. http://channel9.msdn.com/Shows/Going+Deep/C-and-Beyond-2012-Andrei-Alexandrescu-Systematic-Error-Handling-in-C
