How Can I inherit the string class?

Question

I want to inherit to extend the C# string class to add methods like WordCount() and several many others but I keep getting this error:

Er

Answer 1

Another option could be to use an implicit operator.

Example:

class Foo {
    readonly string _value;
    public Foo(string value) {
        this._value = value;
    }
    public static implicit operator string(Foo d) {
        return d._value;
    }
    public static implicit operator Foo(string d) {
        return new Foo(d);
    }
}

The Foo class acts like a string.

class Example {
    public void Test() {
        Foo test = "test";
        Do(test);
    }
    public void Do(string something) { }
}