challenge: implement the max function

[Don Clugston]

Jari-Matti Mäkelä wrote:
> Don Clugston kirjoitti:
>> Lionello Lunesu wrote:
>>> donth ave wrote:
>>>> Xinok Wrote:
>>>>
>>>>> T[0]+T[1]
>>>> To have addition is an additional(sic!) requirement not present in the
>>>> challenge.
>>> Would typeof(T[0]>T[1]?T[0]:T[1]) work? I'd have to test it, I guess :)
>> No, it doesn't work. But this does:
>> (starting to fail the simplicity requirement though...)
> 
> Squeezing a bit might help f) a minor bit more:
> 
> template maxtype(T...){
>     static if(T.length == 0) static assert(false);
>     static if(T.length == 1) alias typeof(T[0]) maxtype;
>     static if(T.length == 2 && is( typeof( (T[0] x, T[1] y){ return y <
> x ? y : x;}) Q == return)) {
>         alias Q maxtype;
>     }
>     static if(T.length > 2) {
>         alias maxtype!(maxtype!(T[0..1]), T[2..$]) maxtype;
>     }
> }
> 
> maxtype!(T) max(T...)(T arg){
>     static if(arg.length == 1) return arg[0];
>     static if(arg.length > 1) return arg[0] >= arg[1] ? arg[0] :
> max(arg[1..$]);
> }
> 
> 
> Doesn't it work as an lvalue for classes now?

Maybe. (does ? : preserve lvalues for classes?)
Pared down to the minimum, it is now:

template maxtype(T...){
   static if(T.length == 1) alias typeof(T[0]) maxtype;
   else static if(T.length > 2)
         alias maxtype!(maxtype!(T[0..1]), T[2..$]) maxtype;
   else static if(is( typeof( (T[0] x, T[1] y){ return y > x ? y : x;})
   Q == return))
         alias Q maxtype;
}

maxtype!(T) max(T...)(T arg){
     static if(arg.length == 1) return arg[0];
     else return arg[0] >= arg[1] ? arg[0] : max(arg[1..$]);
}

mintype!(T) min(T...)(T arg){
     static if(arg.length == 1) return arg[0];
     else return arg[0] <= arg[1] ? arg[0] : min(arg[1..$]);
}

Not too terrible.