Is this the reason why IEquatable<T> was introduced?

Question

Is main reason why IEquatable<T> interface was introduced because it allows you to do the same as the System.Object.Equals method but without having to perform casts?

thank you

Answer 1

To make it type safe, I would think. Equals() takes an object as parameter and hence you will not see an error if you pass in an object of wrong type until you run it.

Answer 2

One reason is so that you can require a class be equatable with a desired type, without necessarily being that type. E.g.

public void MyClass<T> where T : IEquatable<Foo>
{
    private static readonly Foo SpecialFoo = Foo.SpecialFoo;

    public void MyMethodThatProcessesTs(T theT)
    {
        if (theT.Equals(SpecialFoo))
        {
            // process theT.
        }
    }
}

Answer 3

In addition to what @Bala R says, it also avoids boxing when doing custom equality checking between structs.