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copied!<p>I think it's good to create a new type when it makes sense to introduce a new value set into your program. For example, if you are writing a complex calculator, then make a complex number type. If you really just want to "glue" a few variables together for a moment, then a tuple is probably a better choice. Let's say you've got a simple function that gathers two numbers from the console... you might do something like:</p> <pre><code>static void GetNumbers(out int x, out int y) { ... } ... int x, y; GetNumbers(out x, out y); </code></pre> <p>I think it usually makes sense when a "getter" function has a return value but in this case it doesn't because I can't really have two return values. I could go and make a new type called TwoNumbers and use that but I think this quickly becomes more of a problem than a solution. If C# had tuples I may be able to do something like the following:</p> <pre><code>static (int, int) GetNumbers() { ... } ... int x, y; (x, y) = GetNumbers(); </code></pre> <p>Now the really interesting question is: although C# doesn't have this feature am I able to implement it myself with a library? The code you suggest is a start but won't allow me to assign like I've done in the second example. I'm not sure about C# but you can get really darn close to this in C++ by using the fact that <em>a function call can be the left operand to the assignment operator when it's return value is a reference type</em>. Consider the following:</p> <pre><code>// this class is implemented much like yours only with C++ template<typename T1, typename T2> class tuple { ... } ... template<typename T1, typename T2> tuple<T1, T2>& tie(T1 a, T2 b) { ... } ... template<typename T1, typename T2> tuple<T1, T2> get_numbers() { ... } ... int x, y; tie(x, y) = get_numbers(); </code></pre> <p>I'd say that is pretty darn close... instead of <code>(x, y) =</code> we have <code>tie(x, y) =</code>. If you are interested in implementation details, I'll refer you to the TR1 library where I first learned about this:</p> <p><a href="http://www.boost.org/doc/libs/1_41_0/libs/tuple/doc/tuple_users_guide.html#tiers" rel="nofollow noreferrer">http://www.boost.org/doc/libs/1_41_0/libs/tuple/doc/tuple_users_guide.html#tiers</a></p> <p>So to bring all this back to C# 3.0... we can certainly create a generic tuple class as you've shown, but can we create a function like tie to "unpack" the tuple in C#? I haven't tried it, sounds like fun. Without something like that, I'd be reluctant to let a C# tuple library proliferate through my code. </p>

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