Value range propagation for if-else

[bearophile via Digitalmars-d]

Daniel Murphy:

> What happens when a function is called from different places 
> with values with different ranges?  What about when it's called 
> from another compilation unit?

One solution is to ignore such cases, so that feature gives 
useful results only when the source is compiled in the same 
compilation unit.

An alternative solution is to handle the functions that use those 
features like templates, and keep the source available across 
different compilation units. This is perhaps acceptable because I 
think that kind of features is going to be used mostly for 
library code and not for most user functions.

Bye,
bearophile