Just where has this language gone wrong?

[q66]

On Thursday, 19 July 2012 at 14:31:41 UTC, Petr Janda wrote:
>> Array gets sorted, then doubles are removed (uniq) and then 
>> everything is converted to a string (map).
>>
>> Everything was recently introduced around 2.059.
>
> Ok, but what is map!(). What's the point of the exclamation 
> mark, is it a template specialization?

stuff after ! specifies template arguments, in this case a 
predicate; "map" is a standard function in many languages; what 
it does basically is to go over an iterable object, apply the 
predicate function given in the template argument to each element 
and returns a new iterable containing the results of the 
predicate call on each element.