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Comment by Joker_vD | Hacker News Reader

C# got Tuple only in version 7.0 which was released in 2017, if you don't know; while TryParse has been there since 1.0 in 2002. And I'd still prefer to have e.g.

    if ([double val, bool ok] = double.TryParse("5.x5"); ok) {
        Console.WriteLine(val);
    } else {
        Console.WriteLine("err");
    }

Of course, having "var" there would be even nicer.

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This golangism hurts readability, it puts an important piece of logic at the end of a pontentially long line. Usually, it's just an ok test, but it's easy to miss when it isn't.

> This golangism hurts readability,

Lolwut? It's basically the same syntax that "for" has, which is why C2Y is finally getting it; besides, C++ already got it in 2017 — or even in 1998, if you count the "if (int x = f()) { ... }" shape.

"For" statement can become quite messy if used outside of several common patterns. And the fact that c/c++ are getting this so late shows that this is not such an obviously good idea.

I don't really see the semantic difference between your code snippet and

  if (double.TryParse("5.x5", out double val)) { ...

which would be the C# equivalent

Do people miss the word "ergonomically" in my original comment? Because yeah, the semantics is essentially the same, just as it would be the same for e.g.

    double.TryParse("5.x5", out double val, out bool ok);
    if (ok) { ... }

in case of a hypothetical variant of C# that doesn't have functions, only procedures, so you'd have to return the data from subroutine calls by ref/out/globals exclusively. It's still would be the same semantics — but quite different ergonomics.

So out of those three choices: return all results by assigning to ref/out parameters; return one result directly, all other by assigning to ref/out parameters; return all results directly — I personally prefer the last one. Almost nobody prefers the first one, yet people seem to be strangely attached to the second variant for some reason.

"only" 2017? :P it's almost 10 years ago

Anyway C# has this:

var (_, _, population1960, _, population2010) = QueryPopulationDataForYears("New York City", 1960, 2010);

> "only" 2017? :P

My original comment was about "the historical inability of commonly used programming languages (from FORTRAN all the way to, say, Java/C#)..." — sure, by the 2010s (when the FP fad got pretty noticeable) the popular programming languages started getting syntactic sugar for handling products/sums, among other things. But in the seventies, the eighties, the nineties, even the early 2000s, the most popular programming languages didn't really have destructuring. Yes, the fringe ones did have it, e.g. Mesa (1979) — in exactly the "list of variables in square brackets" form — but who the hell used them? The mainstream, until very recently, was the single-value assignment only.

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