C++ 関数例外パフォーマンスの最適化: エラー処理と効率のバランスをとる

void process_file(const std::string& filename) {
  try {
    std::ifstream file(filename);
    // 代码过程...
  } catch (std::ifstream::failure& e) {
    std::cerr << "Error opening file: " << e.what() << std::endl;
  }
}

void process_file_nofail(const std::string& filename) {
  std::ifstream file(filename, std::ifstream::nofail);
  if (!file) {
    std::cerr << "Error opening file: " << file.rdstate() << std::endl;
    return;
  }
  // 代码过程...
}

void process_file_try_catch(const std::string& filename) {
  std::ifstream file(filename);
  try {
    if (!file) {
      throw std::runtime_error("Error opening file");
    }
    // 代码过程...
  } catch (const std::runtime_error& e) {
    std::cerr << "Error: " << e.what() << std::endl;
  }
}

std::exception_ptr process_file_exception_ptr(const std::string& filename) {
  std::ifstream file(filename);
  try {
    if (!file) {
      throw std::runtime_error("Error opening file");
    }
    // 代码过程...
  } catch (const std::runtime_error& e) {
    return std::make_exception_ptr(e);
  }
  return nullptr;
}