Checked vs unchecked exceptions

[Moritz Maxeiner via Digitalmars-d]

On Wednesday, 28 June 2017 at 01:35:32 UTC, mckoder wrote:
> On Tuesday, 27 June 2017 at 22:56:47 UTC, Moritz Maxeiner wrote:
>>
>> You mean the very first time you want to call it and you don't 
>> know the exception set yourself by looking at its signature?
>> Put the call in a nothrow scope and compile the module (which 
>> is fast in D), the compiler will then complain which 
>> exceptions you didn't catch (requires improvement of nothrow 
>> analysis [1]).
>>
>
> So to know what exceptions are possible you have to compile the 
> code?

That, or do the even faster thing and use what's written in the 
documentation (which a sensible person might generate 
automatically, embedding the generated exception set for each 
function).
There are only two outcomes (sans compiler bugs):
- What's written there is correct -> It will compile and you're 
fine
- What's written there is incorrect -> It won't compile and tell 
you what's missing
In the 2nd case you have discovered a bug in whatever codebase 
you are using. Report it.

> I consider that inferior to other solutions such as callee 
> explicitly stating what exceptions it may throw, because then 
> all you have to do is glance at the callee.

On the one hand you have a small one-time cost (I would go as far 
as calling it tiny, since I consider it a reasonable assumption 
for you to have the documentation open), on the other hand you 
have a one-time cost with its size depending on the call 
hierarchy level and small constant maintenance costs on every 
change.
If you consider the first inferior to the second, that's your 
call, but I disagree strongly.
That being said, nothing prevents you from putting it there 
anyway:

---
static assert (throwsExactly!(foo, AException, BException));
void foo() { ... }
---

> Also, I think  explicitly stating your intent in this manner 
> (by the callee not just the caller) is a good idea, to make 
> sure you are not throwing some exception you didn't mean to 
> throw.

Add a static assert as shown above and you're done.