Are value types immutable by definition?

Question

I frequently read that structs should be immutable - aren\'t they by definition?

Do you consider int to be immutable?

int i         


        

Answer 1

No, value types are not immutable by definition.

First, I should better have asked the question "Do value types behave like immutable types?" instead of asking if they are immutable - I assume this caused a lot of confusion.

struct MutableStruct
{
    private int state;

    public MutableStruct(int state) { this.state = state; }

    public void ChangeState() { this.state++; }
}

struct ImmutableStruct
{
    private readonly int state;

    public MutableStruct(int state) { this.state = state; }

    public ImmutableStruct ChangeState()
    {
        return new ImmutableStruct(this.state + 1);
    }
}

[To be continued...]