Template hell apis are necessy for a functional d3

[monkyyy]

> phobos v3 will have less templates, especially conv.to -dconf

```d
struct myint{
   int i;
   bool isvalid;
   int to!int()=>cast(int)i;
}
import std.conv;
myint[][][string] foo;
foo.to!(int[][][string]);
```

A recursive hyper overloaded .to template is the best way to 
support this operation of nested user types; theres things to be 
said about simplifying the std, but its not via removing 
templates as a preemptive style decision.

```d
T[] to(T[],S)(S[] array...){
   T[] output;
   foreach(e;array){
     output~=e;
   }
   return output;
}
```

The average block of std code is about 1000x more complex then 
what I would write but templates are essental complexity here