[cffi-devel] passing value of different type than :int to foreign function

Hi, I have a question about passing values to foreign functions that are not :int. If I define a foreign function as (cffi:defcfun "foo" :void (val :double)) I am not able to call it with (foo 45.0) Because 45.0 is not of type :double. I have tried different ways (convert-to-foreign and so on) but I cannot solve it. Any help is greatly appriciated. // Nik