1 matches bool, 2 matches long

[Maxim Fomin]

On Thursday, 25 April 2013 at 21:05:43 UTC, Ali Çehreli wrote:
> This question has first appeared on D.learn:
>
> ...
>
> The program calls two separate foo() overloads for 1 and 2:
>
> bool
> long
>
> According to the language spec, both overloads match the int 
> argument by "implicit conversion" as described under "Function 
> Overloading" here:
>
>   http://dlang.org/function.html
>
> Then, the overload must be resolved by partial ordering: "If 
> two or more functions have the same match level, then partial 
> ordering is used to try to find the best match. Partial 
> ordering finds the most specialized function."
>
> Is bool more specialized than long or is this a bug? 
> Intuitively, both should match the 'long' overload. It feels 
> like there should at least be ambiguity.
>
> Ali

Looks like value range propagation bug because 1 is integer 
literal and should be converted to long. There is no way for 1 to 
be converted to bool here (from TDPL long is below int and it is 
the shortest way, value range propagation can work upwards, but 
the path would be longer).