"Tuple Declaration"

static void Test() {
	// This line creates a 3-tuple (a tuple with 3 items) named 'userDetails'.
	// The tuple's three properties are an int named Age, a string named Name, and a float named TestScore
	var userDetails = (Age: 30, Name: "Ben", TestScore: 50f);
	// ... Later on we can use the tuple like any old struct/class:
	var age = userDetails.Age;
	var name = userDetails.Name;
	var testScore = userDetails.TestScore;

Code snippet taken from "Complete C# Quick Reference - C# 7".