checkedint call removal

[Walter Bright via Digitalmars-d]

On 7/30/2014 12:54 AM, David Bregman wrote:
> On Wednesday, 30 July 2014 at 03:32:50 UTC, Walter Bright wrote:
>> I don't either. I still have no idea what the difference between assume(i<6)
>> and assert(i<6) is supposed to be.
>
> assert:
> is a runtime check of the condition.
> is a debugging/correctness checking feature.
> is used when the expression is believed true, but is not proven so.
> (if it was proven, then there is no purpose in asserting it with a redundant
> runtime check that is guaranteed to never activate.)
>
> assume:
> passes a hint to the optimizer to allow better code generation.
> is used when the expression is proven to be true (by the programmer, like
> @trusted).

It still means the same thing as assert.


> The only relation between the two is that if a runtime check for (x) is inserted
> at some point, it is safe to insert an assume(x) statement afterwards, because x
> is known true at that point.

I.e. they're the same thing.


> If assert degenerates to assume in release mode, any bugs in the program could
> potentially cause a lot more brittleness and unexpected/undefined behavior than
> they otherwise would have. In particular, code generation based on invalid
> assumptions could be memory unsafe.

Which is why assert can also do a runtime check.