Best practices of using const

[drug]

On 19.02.2019 19:19, Kagamin wrote:
> On Tuesday, 19 February 2019 at 15:30:22 UTC, Atila Neves wrote:
>> I keep hearing how const is nigh unusable in D, and except for ranges 
>> I litter my code with const everywhere, pretty much just as often as I 
>> used in C++.
> 
> I once spent a good amount of effort to annotate my code with pure and 
> inout only to find a compiler bug, then I realized that annotations 
> aren't really needed, because the collection is inherently mutable 
> anyway (appender).

I use const all over the place too. And I made PR to other libraries to 
add const qualifier.
Yes, it sometimes forces me to make a copy of data to mutate it - but 
I'm pretty sure this is the purpose of the qualifier. This helps me to 
catch/prevent bug. So I don't agree with people who do not use const at 
all. Definitely const qualifier in D is usable and is useful. The same I 
can say about properties - for example I use them in meta programming to 
detect what to serialize/process - I skip methods but serialize 
properties and for me this is a nice language feature.