How to make invariant switchable

[Jarrett Billingsley]

On Thu, Jun 18, 2009 at 8:57 AM, Qian Xu<quian.xu at stud.tu-ilmenau.de> wrote:
> Jason House wrote:
>
>> Qian Xu Wrote:
>>
>>> Hi All,
>>>
>>> "invariant" is a great language feature of D. But nice thing costs.
>>>
>>> Is it possible to make it compiler switchable? Like "dmd
>>> --ignore-invariant" or "dmd --version=ignore-invariant" It think it will
>>> be quite helpful to generate test version and release version of
>>> software.
>>>
>>>
>>> Best regards
>>> Qian Xu
>>
>> "dmd -release" will ignore invariants. You can also wrap your invariants
>> inside of debug{} or similar.
>
> Thanks for the hint.
>
> BTW: is assertion switchable as well? I put some assertions outside of
> invariant-block, it will be executed, when my program is compiled in
> release mode.

All the debugging features are optional.  Using -release turns of not
only invariant{} but also in{} and out{} contracts, assert(), and
array bounds checking.  DMD doesn't provide any more fine-grained
support for these, but LDC allows you to turn each of them on or off
individually.