Question on @nothrow

[Vasileios Anagnostopoulos via Digitalmars-d-learn]

On Thursday, 1 June 2017 at 17:03:52 UTC, Ali Çehreli wrote:
> On 06/01/2017 08:41 AM, Vasileios Anagnostopoulos wrote:
>
>> //If I do not know
>>
>> void haveToCommunicateWithAli() {
>> sendEmailToAli();
>> }
>>
>> //can blow-up after code has shipped
>> //and have no chance to recover
>>
>>
>> What shall I do in this case? Thank you in advance.
>>
>> Vasileios
>
> (Sorry if I go to too basic levels here.) I used to think that 
> an unhandled exception was a program crash. It's not. It's a 
> good thing that a program aborts due to an uhandled exception. 
> What happened is that it could not achieve it's task. There was 
> nothing else it could do, so it terminated. (For example, it 
> did not continue with unhealthy radiation levels on the 
> patient.)
>
> Although an abort may be the safest thing to do in many cases, 
> it's not user-friendly. So, you catch the exception at the 
> highest level that it matters or that you can do something 
> about it. For example, you can catch the exception in main(), 
> report a friendly error, and return 1.
>
> Or, you may be in a loop, preparing letters, you catch around 
> that code and either report an error or perhaps grab more 
> stamps and repeat the last operation.
>
> So the answer is, don't catch exceptions any lower than it 
> really matters, which could be as high as the main() function.
>
> Ali

But still I believe that @nothrow should be mandatory if there is 
no possibility for a function to throw something. I understand 
that in the DLL/LIB level this is not possible. However, at least 
in the .di level it should be there.

And if you want my two cents, after reading a lot I came to the 
"personal" conclusion that Exception objects are wrong. For me it 
is enough to have something like

void A() {
  raise;
}

void B() {
  raise;
}

void C() {
  raise;
}


void D () nothrow { //the compiler inferred from body that D 
cannever throw

scope(failure) {
  writeln("The end of the world");
  exit(1);
}

try {
  A();
} else try {
   B();
} else {
  C();
}

}