r6:Define:ALIGN DOUBLE POINTER
#define ALIGN_DOUBLE_POINTER [atom_t size in bytes, multiplied by two]
No return value.
The value to use for this define is sizeof(atom_t), multipled by 2. Unfortunately, compilers do not accept C code as an argument to their alignment keyword, so it is not possible to use sizeof(atom_t)*2 in the source code. As such, it must be provided in a define.