inspect

static VALUE
ossl_engine_inspect(VALUE self)
{
    VALUE str;
    const char *cname = rb_class2name(rb_obj_class(self));

    str = rb_str_new2("#<");
    rb_str_cat2(str, cname);
    rb_str_cat2(str, " id=\"");
    rb_str_append(str, ossl_engine_get_id(self));
    rb_str_cat2(str, "\" name=\"");
    rb_str_append(str, ossl_engine_get_name(self));
    rb_str_cat2(str, "\">");

    return str;
}