The syntax of sort and templates

[Gary Willoughby via Digitalmars-d-learn]

On Friday, 26 May 2017 at 09:59:26 UTC, zakk wrote:
> 1) Why is D making using of the binary ! operator, which as far 
> as I understand introduces a template?

The exclamation mark here is not a binary operator, it's used in 
D templates to define where compile-time parameters are.

> 2) Why is a template needed here?

It's a template so you can use differently typed ranges. Remember 
a range is an interface and very different types can implement it.

> 3) It seems to me like the argument passed to the template is a 
> lambda expression. I only know about templates taking types as 
> argument. What's going on?

The function parameter is defined as an alias which is also valid 
at compile-time.

https://dlang.org/phobos/std_algorithm_sorting.html#sort