updated mir interface

[Alex]

Ok... sorry for being penetrant, but there is still something 
strange. Having dependencies as you had,

´´´
import mir.random.algorithm;
import mir.algorithm.iteration;
import mir.ndslice;
import mir.random;

void fun(size_t s){}

void main()
{
	size_t[] arr;
	arr.length = 42;

	rne.sample(arr, 1).each!(el => fun(el));
	foreach(i; rne.sample(arr, 1)) { i.fun; }
}
´´´

I get

/Users/alex/.dub/packages/mir-random-2.1.2/mir-random/source/mir/random/algorithm.d(573,48): Error: no property front for type ulong[]
/Users/alex/.dub/packages/mir-algorithm-3.0.3/mir-algorithm/source/mir/algorithm/iteration.d-mixin-922(922,5): Error: template instance `mir.random.algorithm.RandomSample!(MersenneTwisterEngine!(ulong, 64LU, 312LU, 156LU, 31LU, 13043109905998158313LU, 29LU, 6148914691236517205LU, 17LU, 8202884508482404352LU, 37LU, 18444473444759240704LU, 43LU, 6364136223846793005LU), ulong[]).RandomSample.front!()` error instantiating
/Users/alex/.dub/packages/mir-algorithm-3.0.3/mir-algorithm/source/mir/algorithm/iteration.d(966,25):        instantiated from here: eachImpl!(__lambda1, RandomSample!(MersenneTwisterEngine!(ulong, 64LU, 312LU, 156LU, 31LU, 13043109905998158313LU, 29LU, 6148914691236517205LU, 17LU, 8202884508482404352LU, 37LU,18444473444759240704LU, 43LU, 6364136223846793005LU), ulong[]))
source/app.d(13,20):        instantiated from here: 
each!(RandomSample!(MersenneTwisterEngine!(ulong, 64LU, 312LU, 
156LU, 31LU, 13043109905998158313LU, 29LU, 6148914691236517205LU, 
17LU, 8202884508482404352LU, 37LU, 18444473444759240704LU, 43LU, 
6364136223846793005LU), ulong[]))
dmd failed with exit code 1.

If I import in mir.random.algorithm.d (2.1.2) in line 534 
std.range, the error goes away. But I assume, that's not the way 
it should be solved, is it?