Calls to struct methods and immutable

[bearophile]

Joseph Rushton Wakeling:

> Is it appropriate to have 'nothrow' given that the assert could 
> fail?

Failing asserts produce errors, not exceptions. "nothrow" only 
deals with exceptions. And thankfully in this case your D code 
doesn't need to be "appropriate", because D refuses nothrow if 
the function is able to throw.


> So, in practice, it seems like that function should cast it to 
> immutable as it returns -- and this would be safe, no?

Try to avoid casts as much as possible in D, they are a great 
source for bugs. Take a look at assumeUnique, or better make  
your makeFoo pure so its output is assignable to immutable.


> By the way, I should add -- I recognize I'm deluging the list 
> with a bunch of questions in these last days, and I'm very 
> grateful for the amount of advice you and others have been 
> giving.  I hope it's not becoming too overwhelming or annoying!

For me it's not a problem: when I don't have time to answer I 
don't answer :-)

Bye,
bearophile