#include <stdio.h>
#include <stdlib.h>
#include <jansson.h>

struct foo {
    int a;
    double b;
    const char *c;
};

static const char format[] = "{s:i, s:f, s:s}";

static json_t *struct_to_json(struct foo *f) {
    return json_pack(format, "a", f->a, "b", f->b, "c", f->c);
}

static struct foo *json_to_struct(json_t *j) {
    struct foo *ret = malloc(sizeof *ret);
    json_unpack(j, format, "a", &ret->a, "b", &ret->b, "c", &ret->c);
    return ret;
}

int main(void) {

    struct foo f = {43, 2.2, "orange"};
    json_t *j = struct_to_json(&f);
    struct foo *g = json_to_struct(j);

    printf("%d %f %s\n", g->a, g->b, g->c);
    json_decref(j);
    free(g);

    return 1;
}