"var" for props/fields

test.cs

static class X
{
    public static X<T> Create<T>(T t) { return new X<T>(t); }
}

class X<T>
{
    T MyT { get; }
    public X(T t)
    {
        MyT = t;
    }
}

class Program 
{
    static void Main() 
    {
        var x = X.Create(10);
    }
}