Function exit_with_error

examples/async.cc:49–61

using handle = std::unique_ptr<T, deleter<T, fn>>;

void exit_with_error(std::string msg, wasmtime_error_t *err,
                     wasm_trap_t *trap) {
  std::cerr << "error: " << msg << std::endl;
  wasm_byte_vec_t error_message;
  if (err) {
    wasmtime_error_message(err, &error_message);
  } else {
    wasm_trap_message(trap, &error_message);
  }
  std::cerr << std::string(error_message.data, error_message.size) << std::endl;
  wasm_byte_vec_delete(&error_message);
  std::exit(1);
}

handle<wasm_engine_t, wasm_engine_delete> create_engine() {
  wasm_config_t *config = wasm_config_new();