How to best implement Equals for custom types?

Question

Say for a Point2 class, and the following Equals:

public override bool Equals ( object obj )

public bool Equals ( Point2 obj )

This is the

Answer 1

Using C# 7 and the is type varname pattern (https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/is#type), provides for a clean Equals(object) that deals with null and type checking using either of the below approaches:

// using Equals(point)
public override bool Equals(object obj) =>
    (obj is Point other) && this.Equals(other);

// using the == operator
public override bool Equals(object obj) =>
    (obj is Point other) && this == other;

Obviously, you need to implement at least one of the following as well:

public bool Equals(Point2 other);
public static bool operator == (Point2 lhs, Point2 rhs);