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