auto ref function parameters in a free function

[Vlad Levenfeld via Digitalmars-d-learn]

On Sunday, 3 August 2014 at 19:43:53 UTC, anonymous wrote:
> If this exact code errors for you, it ... uhh ... could be
> platform specific? Are you on Windows?

Debian, and your code works for me. I figured out the problem - I 
made less_than to serve as a default sorting predicate, so in a 
few places there is something like this:

void sort (R, T = ElementType!R, alias compare = less_than!T)(R 
range, T item)
{...}

And since auto ref parameters need actual parameters to deduce 
whether they should be ref or not, less_than!T isn't an 
instantiated template - its still an alias, because it still must 
choose between having ref and value parameters.

So, it looks like I can't use auto ref with less-than. Which is 
fine, if I need to quickly compare large structures I will just 
pass in a ref_less_than predicate or something.