C# 7 tuples and lambdas

Question

With new c# 7 tuple syntax, is it possible to specify a lambda with a tuple as parameter and use unpacked values inside the lambda?

Example:

var list         


        

Answer 1

You should specify names of tuple properties (well, ValueTuple have fields) otherwise default names will be used, as you have seen:

var list = new List<(int x, int y)>();

Now tuple have nicely named fields which you can use

list.Select(t => t.x * 2 + t.y / 2)

Don't forget to add System.ValueTuple package from NuGet and keep in mind that ValueTuples are mutable structs.

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Update: Deconstruction currently represented only as an assignment to existing variables (deconstructon-assignment) or to newly created local variables (deconstruction-declaration). Applicable function member selection algorithm is the same as before:

Each argument in argument list corresponds to a parameter in the function member declaration as described in §7.5.1.1, and any parameter to which no argument corresponds is an optional parameter.

Tuple variable is a single argument. It cannot correspond to several parameters in the formal parameters list of the method.