extend "in" to all array types

[Tobias Pankrath]

On Wednesday, 15 January 2014 at 17:13:37 UTC, Meta wrote:
>
> auto inWrap(T)(T[] arr)
> {
>     static struct InWrapper
>     {
>         import std.typecons: Nullable;
>
>         private T[] payload;
>
>         Nullable!size_t opBinaryRight(string op: "in")(T val)
>         {
>             Nullable!size_t index;
>             foreach (i, element; payload)
>             {
>                 if (element == val)
>                 {
>                     index = i;
> 					
> 					return index;
>                 }
>             }
>
>             return index;
>         }
>     }
>
>     return InWrapper(arr);
> }
>
> void main()
> {
>     auto arr = [0, 1, 2, 3, 4];
> 	auto i = 2 in arr.inWrap;
>     assert(!i.isNull);
> 	assert(i == 2);
> }

The in-operator should return T* for consistency with the 
build-in ones.