higher-order funcs for ranges (with usual interface)

[Lars T. Kyllingstad]

On Wed, 02 Feb 2011 13:18:07 +0000, Lars T. Kyllingstad wrote:

> [...]
> 
>   struct Map(Range, In, Out)
>       if (isInputRange!Range && is(ElementType!Range : In)
>   {
>       Range input;
>       Out delegate(In) f;
> 
>       @property bool empty() { return input.empty; }
> 
>       // Inefficient, should cache front... @property Out front() {
>       return f(input.front); }
>       
>       void popFront() { input.popFront(); }
>   }
> 
>   Map!(Range, Out) map(Range, In, Out)(Range input, Out delegate(In) f)
>       if (isInputRange!R && is(ElementType!Range : In)
>   {
>       return typeof(return)(input, f);
>   }

Oops, seems i missed a few closing parentheses on the template 
constraints.

-Lars