bottom type as parameter or local variable, does that make sense?

WebFreak001 at
Fri Jan 14 11:52:04 UTC 2022

For example:
import std.stdio;

void foo(noreturn a)
     writeln("we got called!");

void bar()
     noreturn b;

void main()

Guess what it prints and reply to it on this thread. I think the 
result is pretty nonsensical.


Should this usage be allowed? I would say not allowing it would 
make more sense.

Additionally if we don't allow it we could allow aliasing to it 

deprecated("OldType is no longer supported, use NewType instead") 
alias OldType = noreturn;

and with that both add hint messages for users to migrate and not 
allow broken code to compile.

A sample for this would be libdparse, where the arguments of the 
visit functions determine which function is called, even if the 
argument isn't actually used or just ignored. The cases where the 
argument type is specified, but not used, do happen and migrating 
types there to force the user to rewrite code is currently not 
possible without completely removing the type.

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