using unaryFun in functions that take a comparator (eg sort etc): sort!"a[0]" <=> sort!"a[0]<b[0]"

[Andrei Alexandrescu]

On 5/28/13 4:16 AM, Timothee Cour wrote:
> very often I would wish that sort (+ related functions) could take
> unaryFun arguments and convert them to binaryFun as follows:
>
> //pseudocode:
> template unaryToBinaryComp(alias foo) {
> bool unaryToBinaryComp(T)(T a, T b) if (__traits(compiles,foo(a) <
> foo(b)) ) {
> return foo(a) < foo(b);
> }
> }

I actually have a branch in my code that does exactly that. I abandoned 
it because the code, error messages, and documentation got really confusing.

It may be worth to add a keySort algorithm that only works with unary 
keys, but then I thought people can always write a small lambda.


Andrei