Why not move cast to the standard library?

[downs]

Jeremie Pelletier wrote:
> grauzone wrote:
>> Andrei Alexandrescu wrote:
>>> downs wrote:
>>>> Andrei Alexandrescu wrote:
>>>>> downs wrote:
>>>>>> With all the neat template tricks we have in 2.0, and since we're
>>>>>> widely redefining the syntax anyway, why not deprecate the current
>>>>>> cast syntax and move it into object.d as a library function?
>>>>>>
>>>>>> So instead of cast(Foo) bar; you would say cast!Foo(bar); .. save
>>>>>> on a
>>>>>> keyword and demonstrate language power at the same time.
>>>>>>
>>>>>> What sez ye?
>>>>> What would the implementation look like?
>>>>>
>>>>> Andrei
>>>>
>>>> Unions, and LOTS of static ifs. :)
>>>
>>> Unions won't work for casting class objects and interfaces because
>>> those do pointer adjustments. I think cast must be a primitive.
>>
>> When casting interfaces and objects, the primitive cast just calls
>> into runtime (functions like _d_dynamic_cast etc.). I don't see a
>> reason why cast implemented as templated function couldn't call those
>> runtime functions directly.
>>
>>> Andrei
> 
> What about cast(int) or cast(string) and whatnot then? You'd have
> cast!A(B) for classes and cast(int) for values, that would be backwards.
> 
> Jeremie

What about cast!int could _not_ be done as a function?