Why does Phobos not provide a method to easily deconstruct tuples? Here's a trivial implementation:

//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.

On Saturday, 20 July 2024 at 14:02:21 UTC, IchorDev wrote:

Not having this is like if Phobos didn't have `AliasSeq`. Yes you can make your own, but it's wasteful boilerplate.

Instead of the tie assignment, you can just do:

	import std.meta;
	AliasSeq!(y, x) = tupRetFn().expand;

On Saturday, 20 July 2024 at 20:48:29 UTC, Nick Treleaven wrote:

	import std.meta;
	AliasSeq!(y, x) = tupRetFn().expand;

And here I was trying to use comma expressions for this like a buffoon! Of course they didn't work, but I'm pleasantly surprised that using a sequence does. I should really PR std.typecons to add a couple of examples of this, because I think a lot of people will have overlooked it.
I honestly thought there was no way to do this in D for the longest time until I saw some C++ code using std::tie and I realised that obviously the same thing is doable in D using opAssign, and then refined it to use UFCS because the syntax Tie!(y,x)() was a bit clunky.

On Sunday, 21 July 2024 at 04:05:52 UTC, IchorDev wrote:

	import std.meta;
	AliasSeq!(y, x) = tupRetFn().expand;

I think The lvalue sequence docs in template.dd were only updated in the last year to mention sequence assignment.

Good idea.