OverridingClassEquality.cs

public class Foo : IEquatable<Foo>
{
    public int Bar { get; set; }
    public int Baz { get; set; }

    public override bool Equals(object obj)
    {
        return this.Equals(obj as Foo);
    }
    
    public bool Equals(Foo other)
    {
        if (Object.ReferenceEquals(other, null))
            return false;
        if (Object.ReferenceEquals(this, other))
            return true;
            
        return this.Bar.Equals(other.Bar) &&
            this.Baz.Equals(other.Baz);
    }
    
    public override int GetHashCode()
    {
        unchecked
        {
            int hash = 17;
            hash = hash * 23 + this.Bar.GetHashCode();
            hash = hash * 23 + this.Baz.GetHashCode();
            return hash;
        }
    } 
}

OverridingStructEquality.cs

public struct Foo : IEquatable<Foo>
{
    public int Bar { get; set; }
    public int Baz { get; set; }
    
    public override bool Equals(object obj)
    {
        return (obj is Foo) && this.Equals((Foo)obj);
    }
    
    public bool Equals(Foo other)
    {
        return this.Bar.Equals(other.Bar) &&
            this.Baz.Equals(other.Baz);
    }
    
    public override int GetHashCode()
    {
        unchecked
        {
            int hash = 17;
            hash = hash * 23 + this.Bar.GetHashCode();
            hash = hash * 23 + this.Baz.GetHashCode();
            return hash;
        }
    } 
}