checkedint call removal

[John Colvin via Digitalmars-d]

On Monday, 28 July 2014 at 12:52:07 UTC, John Colvin wrote:
> On Monday, 28 July 2014 at 12:08:39 UTC, Daniel Murphy wrote:
>> "John Colvin"  wrote in message 
>> news:iguetbdxlyilavlizqry at forum.dlang.org...
>>
>>> To what extent can a compiler use assertions? Can it work 
>>> backwards from an assert to affect previous code?
>>>
>>> void foo(int a)
>>> {
>>>    enforce(a & 1);
>>>    assert(a & 1);
>>> }
>>
>> The assert is dead code, because it will never be reached if 
>> (a & 1) is false.
>>
>>> void bar()
>>> {
>>>    assert(a & 1);
>>>    enforce(a & 1);
>>> }
>>
>> The throw inside enforce is dead code, because it will never 
>> be reached if (a & 1) is false.
>>
>> The compiler is free to remove dead code, because it doesn't 
>> change the program's behaviour.
>
> Ok. What about this:
>
> int c;
>
> void foo(int a)
> {
>     if(a < 0) c++;
>     assert(a > 0);
> }
>
> I presume that cannot be optimised away entirely to:
>
> void foo(int a) {}
>
> ?

sorry, I mean

void foo(int a)
{
     assert(a > 0);
}

of course you can't optimise away the check.