What is C# analog of C++ std::pair?

Question

I\'m interested: What is C#\'s analog of std::pair in C++? I found System.Web.UI.Pair class, but I\'d prefer something template-based.

Than

Answer 1

The PowerCollections library (formerly available from Wintellect but now hosted on Codeplex @ http://powercollections.codeplex.com) has a generic Pair structure.

Answer 2

Apart from custom class or .Net 4.0 Tuples, since C# 7.0 there is a new feature called ValueTuple, which is a struct that can be used in this case. Instead of writing:

Tuple<string, int> t = new Tuple<string, int>("Hello", 4);

and access values through t.Item1 and t.Item2, you can simply do it like that:

(string message, int count) = ("Hello", 4);

or even:

(var message, var count) = ("Hello", 4);

Answer 3

Unfortunately, there is none. You can use the System.Collections.Generic.KeyValuePair<K, V> in many situations.

Alternatively, you can use anonymous types to handle tuples, at least locally:

var x = new { First = "x", Second = 42 };

The last alternative is to create an own class.

Answer 4

On order to get the above to work (I needed a pair as the key of a dictionary). I had to add:

    public override Boolean Equals(Object o)
    {
        Pair<T, U> that = o as Pair<T, U>;
        if (that == null)
            return false;
        else
            return this.First.Equals(that.First) && this.Second.Equals(that.Second);
    }

and once I did that I also added

    public override Int32 GetHashCode()
    {
        return First.GetHashCode() ^ Second.GetHashCode();
    }

to suppress a compiler warning.

Answer 5

I was asking the same question just now after a quick google I found that There is a pair class in .NET except its in the System.Web.UI ^ ~ ^ (http://msdn.microsoft.com/en-us/library/system.web.ui.pair.aspx) goodness knows why they put it there instead of the collections framework

Answer 6

C# has tuples as of version 4.0.