Chez Scheme FFI - Structs returned by value

struct-by-value.ss

(load-shared-object "./libsbv.so")

(define-ftype color
  (struct
    [r float]
    [g float]
    [b float]
    [a float]))

(define make-rgba
  (foreign-procedure "make_rgba" (float float float float) color))

;; => invalid (non-base) foreign-procedure result ftype color

struct_by_value.c

/* -*- compile-command: "gcc -c -Wall -Werror -fpic -o sbv.o struct_by_value.c; and gcc -shared -o libsbv.so sbv.o"; -*- */

struct color {
  float r;
  float g;
  float b;
  float a;
};

struct color from_rgba(float r, float g, float b, float a) {
  struct color c;
  c.r = r;
  c.g = g;
  c.b = b;
  c.a = a;
  return c;
}