2

我想在我的异常处理中添加有关程序将要做什么的信息。旧代码对try所有内容都有一个大块：

try {
  read_cfg();  // a sub call might throw runtime_error
  operation1();
  operation2();
}
catch (std::exception& e) {
  std::cerr
    << "Error: " << e.what() << ", "
    // FIXME: also show what we were trying to do
    // FIXME: and what a user could try
    << "\n";
}

错误信息示例：

Error: file "foo.cfg" not found, while reading configuration.
Please make sure the file exists.

我将try-block 转换为三个块，但这感觉很奇怪：

try {
  read_cfg();  // a sub call might throw runtime_error
}
catch (std::exception& e) {
  std::cerr
    << "Error: " << e.what() << ", "
    << "while reading configuration."
    << "\n";
}
try {
  operation1();
}
catch (std::exception& e) {
  std::cerr
    << "Error: " << e.what() << ", "
    << "while performing operation 1."
    << "\n";
}
try {
  operation2();
}
catch (std::exception& e) {
  std::cerr
    << "Error: " << e.what() << ", "
    << "while performing operation 2."
    << "\n";
}

我还尝试为每个调用引入一个异常类（read_cfg_exception, operation1_exception, operation2_exception）。由于在 read_cfg() 调用 open可能会抛出，我捕获它的异常并将其转换为 a read_cfg_exception，从而保存附加信息，即“在读取配置时”出现错误。然而，这也感觉不对：

class read_cfg_exception;
void open(std::string name); // might throw std::runtime_error

void read_cfg()
{
  try {
    open("foo.cfg");
  }
  catch (std::runtime_error& e) {
    throw read_cfg_exception(e.what() + "while reading configuration");
  }
}

因此我有一个问题：什么是一个好的模式来显示错误发生时程序正在做什么的附加信息。

4

1 回答 1

0

take a look at POCO (c++ library) throwing system, that should answer all your questions, you'll learn a lot from that and many good style rules too. The answare to your question will be really long unfortunately (at least I don't know how to make it short).

Anyway don't implement something that makes your code not readable, in your example code is not readable and then not maintainable wich is not wanted.

于 2012-12-03T11:44:33.960 回答