Sean Kelly wrote:
> You can for the above case.  But D also supports:
> 
>     catch{ ... }
> 
> ie. without the "(Exception e)".  However, unlike C++, "throw;" in this instance is invalid so there's no way to rethrow the exception.
> 
> Basically, I'm wondering why this form of catch exists.  It can catch exceptions but not report anything about them (as it has no object reference), and it can't rethrow them.  I can't think of a single case where I would actually use this statement as it exists now.

Gotcha, and neither can I

On Wed, 07 Jun 2006 17:50:09 -0700, kris wrote:

> Sean Kelly wrote:
>> You can for the above case.  But D also supports:
>> 
>>     catch{ ... }
>> 
>> ie. without the "(Exception e)".  However, unlike C++, "throw;" in this instance is invalid so there's no way to rethrow the exception.
>> 
>> Basically, I'm wondering why this form of catch exists.  It can catch exceptions but not report anything about them (as it has no object reference), and it can't rethrow them.  I can't think of a single case where I would actually use this statement as it exists now.
> 
> Gotcha, and neither can I

I have this routine that I use ...

 bool FileExists(char[] pFileName)
 {
    if (pFileName in lExistingFiles)
    {
        return true;
    }
    try {
      if(std.file.isfile(pFileName) && std.file.exists(pFileName))
      {
        lExistingFiles[pFileName] = true;
        return true;
      }
    } catch { };
    return false;
 }

The idea being that I really don't care what exception is thrown by the called functions 'isfile' and 'exists', but if any exception is thrown then I want to prevent the program from crashing and also inform my caller about the information they requested - namely that the file specified doesn't exist.

-- 
Derek
(skype: derek.j.parnell)
Melbourne, Australia
"Down with mediocracy!"
8/06/2006 11:01:06 AM

James Pelcis wrote:
> overly interrupting the program.  I think the rationale is that after you have taken the time to handle an exception, why would you rethrow it?

This is very common:

connection.open();
try {
    // ...
} catch {
    connection.close();
    throw;
}

Of course, I could replace that with the on_scope keyword.