The function foreign-type-size
return the size of
type in bytes. This includes any padding within and following
the in-memory representation as needed to create an array of
type objects.
(defcstruct foo (a :double) (c :char)) CFFI> (foreign-type-size :double) => 8 CFFI> (foreign-type-size :char) => 1 CFFI> (foreign-type-size 'foo) => 16