The FLI :const
type corresponds to the C const
type qualifier. The behavior of a :const
is exactly the same as the behavior of its type , and it is only included to ease the readability of FLI code and for naming conventions.
In the following example a constant is allocated and set equal to 3.141.
(setq pi1 (fli:allocate-foreign-object
:type '(:const :float)))
(setf (fli:dereference pi1) 3.141))