<PackageReference Include="System.ValueTuple" Version="4.5.0-rc1" />

System.ValueTuple<T1, T2, T3>

Represents a 3-tuple, or triple, as a value type.
namespace System { public struct ValueTuple<T1, T2, T3> : IEquatable<(T1, T2, T3)>, IStructuralEquatable, IStructuralComparable, IComparable, IComparable<(T1, T2, T3)>, System.ITupleInternal { public T1 Item1; public T2 Item2; public T3 Item3; public ValueTuple(T1 item1, T2 item2, T3 item3); public bool Equals((T1, T2, T3) other); public int CompareTo((T1, T2, T3) other); } }