Tuple deconstruction in Phobos

[IchorDev]

Why does Phobos not provide a method to easily deconstruct 
tuples? Here's a trivial implementation:
```d
//Similar to C++'s `std::tie`. Can anyone tell me why it's called 
`tie`?
void tie(T...)(typeof(T) src){
	static foreach(ind, i; src){
		T[ind] = i;
	}
}

//Usage example:
import std.stdio, std.typecons;

auto tupRetFn() => tuple(47, "test!");

void main(){
	string x = "discarded";
	int y;
	tie!(y, x) = tupRetFn().expand;
	writeln(x,", ",y);
}
```
Not having this is like if Phobos didn't have `AliasSeq`. Yes you 
can make your own, but it's wasteful boilerplate.