问使用.Call()将s4对象发送到C结构

EN

setClass("MyClass", slots = list(x = "numeric", y = "integer"))
r_instance = new("MyClass", x = rnorm(5), y = as.integer(1:10))
dyn.load("parse.so")
.Call("parse", r_instance)

#include <R.h>
#include <Rinternals.h>
#include <Rmath.h>

typedef struct {
  double x;
  int y;
} MyStruct;

SEXP parse(SEXP r_instance){
  MyStruct c_instance = MAKE_S4_INTO_STRUCT(r_instance);
  printf("%g %d\n", c_instance->x[0], c_instance->y[0]);
  return R_NilValue;
}