Re: Exception class with shift operator

Jorgen Grahn wrote:


When using exceptions, it usually looks like this:

 try {
   ... // lots of stuff
 } catch( std::exception const& e) {
  ...
 }

IOW, I usually don't care which exception occurred, but I do care that it is
derived from std::exception because otherwise I need to add additional
catch() clauses. In many cases I just throw std::runtime_error, because it
allows me to give a string message to its constructor. In other cases,
where I need a special exception[1], I also usually derive them from
runtime_error, because that already carries the string.

Uli

[1] Typically one that carries errorcodes from a C API:

  struct errno_exception: runtime_error {
    errno_exception( char const* function, int e, char const* comment = 0);
  };

  void* x = malloc(100);
  if(!x)
    throw errno_exception( "malloc", ENOMEM);

Note: the above code is in fact only semi-complete, because 'x' doesn't
handle the resource it handles in an exception-safe way.

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