size_t size
This is set by libffi; you should initialize it to zero.
unsigned short alignment
This is set by libffi; you should initialize it to zero.
unsigned short type
For a structure, this should be set to FFI_TYPE_STRUCT.
ffi_type **elements
This is a ‘NULL’-terminated array of pointers to ffi_type
objects. There is one element per field of the struct.
Note that ‘libffi’ has no special support for bit-fields. You
must manage these manually.