#include <cassert>
#include <cstring>

#include <mongoc.h>

void log_bson(const bson_t *bson) {
  char *json = bson_as_json(bson, NULL);
  puts(json ? json : "[bson_as_json_error]");
  if (json) bson_free(json);
}

int main() {
  bool status;
  bson_t bson = BSON_INITIALIZER;
  bson_t child = BSON_INITIALIZER;
  status = bson_append_document_begin(&bson, "$set", 4, &child);
  assert(status);
  status = bson_append_bool(&child, "foo", 3, true);
  assert(status);
  status = bson_append_document_end(&bson, &child);
  assert(status);
  log_bson(&bson);
  bson_reinit(&child); // <- this line destroy bson object
  //child = BSON_INITIALIZER; <- this seems no hurt, in C++ 11 mode
  log_bson(&bson);
}