Rant after trying Rust a bit

[Tobias Müller via Digitalmars-d]

Walter Bright <newshound2 at digitalmars.com> wrote:
> On 7/23/2015 12:50 PM, Tobias Müller wrote:
>> TBH I'm very surprised about that argument, because boolean conditions with
>> version() were dimissed for exactly that reason.
> 
> I knew someone would bring that up :-)
> 
> No, I do not believe it is the same thing. For one thing, you cannot test
> the various versions on one system. On any one system, you have to take
> on faith that you didn't break the version blocks on other systems.
> 
> This is quite unlike D's template constraints, where all the combinations
> can be tested reliably with a unittest{} block.

How is this related to testability? Using boolean conditions does not
introduce any new code paths compared to helper versions/ helper traits.
Testability is exactly the same.

My point was that you argued with cleaner design in the case of versions.
*I agree with that*, and I think the same is true for traits.
Even if you're right and testability is better, that doesn't contradict the
point that I'm trying to make.

Tobi