C# 7–Deconstruction

With the introduction of ValueTuple in C# 7, the C# team also introduced support for deconstruction that allows you to split out a ValueTuple in its discrete arguments:

	int code;
	string message;
	var pair = (42, "hello");
	(code, message) = pair; // deconstruct a tuple into existing variables

view raw deconstructtuple.cs hosted with ❤ by GitHub

The nice thing is that this feature is not limited to tuples; any type can be deconstructed, as long as it has a Deconstruct method with the appropriate out parameters:

	public class Version
	{
	public Version(int major, int minor, int build, int revision)
	{
	Major=major;
	Minor=minor;
	Build=build;
	Revision=revision;
	}
	public int Major{get;}
	public int Minor{get;}
	public int Build{get;}
	public int Revision{get;}
	public void Deconstruct(out int major, out int minor, out int build, out int revision)
	{
	major = this.Major;
	minor = this.Minor;
	build = this.Build;
	revision = this.Revision;
	}
	}
	var version =new Version(1,2,3,4);
	var (major, minor, build, _) = version;

view raw Version.cs hosted with ❤ by GitHub

Remark: The Deconstruct method can also be an extension method.