checkedint call removal

[Tofu Ninja via Digitalmars-d]

On Wednesday, 30 July 2014 at 15:49:33 UTC, Daniel Murphy wrote:
> "Tofu Ninja"  wrote in message 
> news:dtjqnyucskwnqjvksawg at forum.dlang.org...
>
>> Question?
>> If an if condition throws or returns in its body is it ok for 
>> the optimizer to 'assume' that the condition is false after 
>> and make optimizations for it? If so then every one 
>> complaining that assert gets removed in -release should really 
>> just be using enforce.
>
> Yes.  In fact, it's required that an optimizer do this in order 
> not to be considered garbage.
>
>> The possibility for the optimizer to make the same 
>> optimizations for assert can be done for enforce, the only 
>> difference is that it does not get removed in -release....
>
> Not quite.  With enforce, it is impossible (ignoring hardware 
> or optimizer errors) for the condition to be false if the 
> enforce was not triggered. Because the assert is not checked, 
> the condition could be false and the code could do something 
> awful.
>
> Also, the optimizer can only use the enforce's assumption 
> _after_ it has checked the condition.  Since with assert it 
> doesn't need to check, it can go backwards and assume the 
> previous code will never produce a value that can violate the 
> assertion.
>
> if (y > 7) // x can't possibly be >= 5, so this can't be true
>  x = y + 1;
> assert(x < 5);
>
> if (y > 7) // the program will throw if >= 5, but that doesn't 
> mean it can't be true
>  x = y + 1;
> enforce(x < 5);
>
> Assert is much much more powerful.

Ok so what is sounds like, is that assert is really what every 
one claims assume is and enforce is what every one claims assert 
is...

Maybe a documentation change on assert is all that is needed, it 
seems like the docs describe assert as something similar to 
enforce. Maybe it should be described in a way similar to assume 
with the added benefit that in non-release modes it will actually 
check that it is true at runtime. Also if that was changed then 
the documentation on version(assert) would need changing too.